Polar Bear Suburban

[NastyBuzzard]

Originally Posted by DirtyLarry

Nah, I sure don't. That project was 10 years ago in 2006. Built it for a friend that lives in Detroit. It got an AM General 6.5L backed by a TH400. He swapped in a 4L80E and painted it when it got to Michigan.

Ahh I see. I am just trying to figure out how I will have to do it or what I will need. I am supposed to be picking up my NV4500 today. It has the bellhousing on it for the 6.5 which from my research should bolt up to any standard SBC bolt pattern. I think the hydraulic clutch setup is on the passenger side though or something. I see you used the AA bellhousing.

[83GMCK2500]

Hi Larry, I've read through this thread, the NV4500 swap thread, and the 8.1 install thread for the K10 and I have some questions for you. I'm looking for big block exhaust recommendations/advice and your threads were the first that came to mind. I am past due for exhaust on my '96 and after reading through your threads I recognize you've got a lot of big block experience. If you have the time or inclination to impart any exhaust wisdom upon me, I would appreciate it. If you would like to reply back to me in my thread on my '96 instead of cluttering your thread that works for me.

I've got just under 290k miles on my truck and for the last 20k or so I've had something rattling in the muffler, I assume a weld has broken internally. It's obnoxious and I find it embarrassing.

Ultimately, when this is no longer my daily driver, I'd like to freshen up the engine, rebuild the heads, and put a more aggressive cam in it, injectors, 0411 ECM swap and tune. I would like to replace everything from the manifolds back and I'm considering a dual in/out muffler (unless otherwise recommended), at this time I'm looking at the oval 5x11 Magnaflow mufflers. Unless absolutely recommended I wasn't going to do headers at this time. When the time comes for those, this shop is local to me. I'm open to not replacing the cats, I'm prepared to have it tuned for that (now) or dummy O2 sensors.

The questions I haven't been able to find the answers for: what size exhaust to run on a big block, what kind of backpressure/velocity/flow characteristics are ideal? Do I use two separate mufflers but incorporate an x-/h-pipe before them or is the Mf 5x11 with internal x sufficient? I'm shooting for "not obnoxious at highway speeds" but sounds good if I get on it. I would think that my wheelbase (will take exhaust to behind duals with stock appearance) will help quiet it. With my gearing I'm running ~2,500RPM +/- 100-150 on the highway, depending on speed limit. The muffler is available in/out: 2.5/2.5, 3/2.5, or 3/3. What size do you think is appropriate? In my research to try and find what size exhaust you used on your vehicles I came across your L18 swap resource thread on CK5 and I read about the redesigned cat. converters on the '06+ vehicles. Should I try and source a pair of the new ones? Lastly, I'll be using mandrel bent tubing for the bends.

[DirtyLarry]

Originally Posted by NastyBuzzard

Ahh I see. I am just trying to figure out how I will have to do it or what I will need. I am supposed to be picking up my NV4500 today. It has the bellhousing on it for the 6.5 which from my research should bolt up to any standard SBC bolt pattern. I think the hydraulic clutch setup is on the passenger side though or something. I see you used the AA bellhousing.

Correct, the 6.5L bell is no different than any other SBC or BBC. You didn’t mention if your ’88 crew cab already has a manual trans or not. If so, you already have the hydro pedals but the master cylinder for the square bodies is not compatible with the slave that would be on the passenger’s side on a factory NV4500 bellhousing. That is the exact reason why I use the AA bells on my K10 and Burb….so I can use the square body specific driver’s side mount slave cylinder and off the shelf factory GM square body hydro hose. AA has two bell housings as well, one for the 1 gen NV4500 and another for the second gen (trans to bell mounting holes are different). If you go the route of the AA bell you’ll need to determine what year your NV4500 is. Pretty much it comes down to if the NV4500 has the deep granny gear and the shift lever that push and twists on you have the 1st gen. If the shift tower is held on by 4 bolts and the lever itself screws on to the tower then you have the second, which would be the same that I have in both of mine. Personally, I would not use a factory GMT400 bellhousing on a square body due to the slave location and the way the hydro hose is connected (square bodies have screw in fittings and GMT400 have push in). Outside of creating a custom hose, there is no a hydro hose with a screw in fitting on the m/c side and push in on the slave side.

Originally Posted by 83GMCK2500

Hi Larry, I've read through this thread, the NV4500 swap thread, and the 8.1 install thread for the K10 and I have some questions for you. I'm looking for big block exhaust recommendations/advice and your threads were the first that came to mind. I am past due for exhaust on my '96 and after reading through your threads I recognize you've got a lot of big block experience. If you have the time or inclination to impart any exhaust wisdom upon me, I would appreciate it. If you would like to reply back to me in my thread on my '96 instead of cluttering your thread that works for me.

I've got just under 290k miles on my truck and for the last 20k or so I've had something rattling in the muffler, I assume a weld has broken internally. It's obnoxious and I find it embarrassing.

Ultimately, when this is no longer my daily driver, I'd like to freshen up the engine, rebuild the heads, and put a more aggressive cam in it, injectors, 0411 ECM swap and tune. I would like to replace everything from the manifolds back and I'm considering a dual in/out muffler (unless otherwise recommended), at this time I'm looking at the oval 5x11 Magnaflow mufflers. Unless absolutely recommended I wasn't going to do headers at this time. When the time comes for those, this shop is local to me. I'm open to not replacing the cats, I'm prepared to have it tuned for that (now) or dummy O2 sensors.

The questions I haven't been able to find the answers for: what size exhaust to run on a big block, what kind of backpressure/velocity/flow characteristics are ideal? Do I use two separate mufflers but incorporate an x-/h-pipe before them or is the Mf 5x11 with internal x sufficient? I'm shooting for "not obnoxious at highway speeds" but sounds good if I get on it. I would think that my wheelbase (will take exhaust to behind duals with stock appearance) will help quiet it. With my gearing I'm running ~2,500RPM +/- 100-150 on the highway, depending on speed limit. The muffler is available in/out: 2.5/2.5, 3/2.5, or 3/3. What size do you think is appropriate? In my research to try and find what size exhaust you used on your vehicles I came across your L18 swap resource thread on CK5 and I read about the redesigned cat. converters on the '06+ vehicles. Should I try and source a pair of the new ones? Lastly, I'll be using mandrel bent tubing for the bends.

Hey Devin,

Cool! Sounds like a fun project. Yeah, the guts probably came loose on your muffler. I had a 2005 Silverado HD that did the same thing…..very annoying. Regarding the cats, if you can get away with replacing the cats with a “test” pipe like I have on my Suburban (wink, wink) you could have whoever is doing the ECM tuning just tune out the rear sensors instead of dummy sensors.

Regarding exhaust pipe size for a BBC, it seems the preferred size is 2.5” where claims of 3” or bigger takes too much back pressure way equaling loss of low end torque and anything smaller is too restrictive. I couldn’t really tell you on velocity/flow characteristics as that seems to be what appeals to each person’s ear but I can tell you that an older BBC, like the Vortec 454 you’re working on, requires a completely different muffler/exhaust configuration than an LS engine or even an 8.1L due to the different firing orders of the newer engines (1-8-7-2-6-5-4-3) compared to the older engines (1-8-4-3-6-5-7-2). The newer firing order engines absoluty need an H, X or x-muffler to sound right, otherwise they wound sounding like two poorly running 4 bangers having a shootout while the older engines like yours sound darn good with true duals, with two individual mufflers. I personally have never had an H or X pipe in an older firing order engine as I always thought they sounded good just plumbed the old school way (twice pipes with two mufflers).

My K10 has true duals, H-pipe and two individual Thrush mufflers (Cheap $30 Flowmaster knock offs). This same exhaust was on the truck when it had a 454 and sounded great but once I swapped in the 8.1L with the different firing order it sounded horrible. Added the H-pipe and now it sounds like a mix between a 60’s muscle car at WOT, cackle of a medium duty truck at low RPM and a Ferrari at cruise. Very weird, but it sounds awesome to my ear. Meanwhile, the Burb’s 8.1L is running a dual inlet/dual outlet Magnaflow X-muffler (can’t remember the exact name and I’m not home to look up the part number) but it sounds great with zero drone found with the typical dual inlet/outlet mufflers. Really quiet idle and cruise but it has a set of LUNGS at WOT almost like there is an exhaust cut out welded in somewhere. The videos posted of my Suburban are not the new Magnaflow exhaust but the old out 2” Flowmaster that sounded great with a 350 but a 50 caliber machine gun spinning at 50,000 RPM’s with an 8.1L. It was horrible. If it were me with an L29 454, I would go with cat “test” pipes and 2 individual Flowmasters or Thrush Flowmaster knock-offs (not a dual inlet/dual outlet muffler). Dual inlet/dual outlet on a 1-8-4-3-6-5-7-2 engine makes way too much interior drone for my liking. Dealt with that on my old ’98 Z71. Not sure if that helps you or adds more to the confusion but that I my offering to your question. I’m sure the heck no exhaust expert. My wife says I'm deaf anyway so my trucks may sound like crap to other people but they sound good to me now

Oh, I almost forgot....I have a Flowmaster dual in/out Big Block Muffler on a '93 C1500 with a 454 and it drones like mad. Sounds good, but the drone at throttle tip in is pretty sucktastic. It sound great on the outside though

[NastyBuzzard]

I apologize I did not specify. Unfortunately my 88 crew cab originally had a 350TBI/TH400 and is 2wd.

I do know that I have the 1st gen of the NV4500, it is from a 94 and has the 6.34 first gear. The shifter is bolted differently than yours. I just picked it up yesterday.

My friend had mentioned I swap to the internal slave type or get a universal slave that I can put lines out the drivers side. I am not sure if that is really an option.

I am just trying to do this on a reasonable budget, my current scope is to keep this as a work horse or tow pig type build and not let it snowball into another expensive project.

I know since I will be going diesel I will have to swap to hydroboost. My 78 crew cab 4x4 that donated its dana 60 had hydroboost so there is a start or at least a core. Unfortunately it was a 350/th350 combo. I never thought I would be lucky enough to find a NV4500 at a price I could pay.

Thank you for your advice on this and knowledge. I really appreciate it.

[y5mgisi]

Just for fun I would like to add in my planned exhaust on my crew cab. It will be a 396 with a nearly stock cam. I don't know why but I am insanely excited about the exhaust I'm going to give it! It will have factory exhaust manifolds, dual 2.5" pipe, an 18" glass pack/resonator on each side where the cats would normally be, an H pipe, and big dynomax turbo mufflers. I think it should sounds very quite at idle, should be totally drone free, but should still provide a slight rumble and a decent pop at wot. Can't wait!

[83GMCK2500]

Originally Posted by DirtyLarry

Hey Devin,

Cool! Sounds like a fun project. Yeah, the guts probably came loose on your muffler. I had a 2005 Silverado HD that did the same thing…..very annoying. Regarding the cats, if you can get away with replacing the cats with a “test” pipe like I have on my Suburban (wink, wink) you could have whoever is doing the ECM tuning just tune out the rear sensors instead of dummy sensors.

Regarding exhaust pipe size for a BBC, it seems the preferred size is 2.5” where claims of 3” or bigger takes too much back pressure way equaling loss of low end torque and anything smaller is too restrictive. I couldn’t really tell you on velocity/flow characteristics as that seems to be what appeals to each person’s ear but I can tell you that an older BBC, like the Vortec 454 you’re working on, requires a completely different muffler/exhaust configuration than an LS engine or even an 8.1L due to the different firing orders of the newer engines (1-8-7-2-6-5-4-3) compared to the older engines (1-8-4-3-6-5-7-2). The newer firing order engines absoluty need an H, X or x-muffler to sound right, otherwise they wound sounding like two poorly running 4 bangers having a shootout while the older engines like yours sound darn good with true duals, with two individual mufflers. I personally have never had an H or X pipe in an older firing order engine as I always thought they sounded good just plumbed the old school way (twice pipes with two mufflers).

My K10 has true duals, H-pipe and two individual Thrush mufflers (Cheap $30 Flowmaster knock offs). This same exhaust was on the truck when it had a 454 and sounded great but once I swapped in the 8.1L with the different firing order it sounded horrible. Added the H-pipe and now it sounds like a mix between a 60’s muscle car at WOT, cackle of a medium duty truck at low RPM and a Ferrari at cruise. Very weird, but it sounds awesome to my ear. Meanwhile, the Burb’s 8.1L is running a dual inlet/dual outlet Magnaflow X-muffler (can’t remember the exact name and I’m not home to look up the part number) but it sounds great with zero drone found with the typical dual inlet/outlet mufflers. Really quiet idle and cruise but it has a set of LUNGS at WOT almost like there is an exhaust cut out welded in somewhere. The videos posted of my Suburban are not the new Magnaflow exhaust but the old out 2” Flowmaster that sounded great with a 350 but a 50 caliber machine gun spinning at 50,000 RPM’s with an 8.1L. It was horrible. If it were me with an L29 454, I would go with cat “test” pipes and 2 individual Flowmasters or Thrush Flowmaster knock-offs (not a dual inlet/dual outlet muffler). Dual inlet/dual outlet on a 1-8-4-3-6-5-7-2 engine makes way too much interior drone for my liking. Dealt with that on my old ’98 Z71. Not sure if that helps you or adds more to the confusion but that I my offering to your question. I’m sure the heck no exhaust expert. My wife says I'm deaf anyway so my trucks may sound like crap to other people but they sound good to me now

Oh, I almost forgot....I have a Flowmaster dual in/out Big Block Muffler on a '93 C1500 with a 454 and it drones like mad. Sounds good, but the drone at throttle tip in is pretty sucktastic. It sound great on the outside though

Fantastic information, thank you very much. I had a feeling I came to the right forum and the right thread. Experience is invaluable, thank you for sharing yours. I will take your muffler suggestion under advisement as well, will probably be listening to a lot of youtube videos and/or soundclips.

[Chevy3+3]

Hey Larry I thought I read somewhere that you have had problems with your 5th gear nut on your NV4500's. I just got done with my swap over a week ago and had been driving my truck everyday and just last night developed a ringing/rattling sound only in 5th gear. The noise doesn't really change when 5th gear is under load or not.

Does this sound like a 5th gear nut problem and what have you found to be a good fix for this. I really don't have much money to throw at it and I'm told my tranny doesn't have many miles on the rebuild. I know some have welded the nut on with great results but also know that sometimes the welds break and then you must install a new shaft.

What are your thoughts, Thanks

[DirtyLarry]

Originally Posted by Chevy3+3

Hey Larry I thought I read somewhere that you have had problems with your 5th gear nut on your NV4500's. I just got done with my swap over a week ago and had been driving my truck everyday and just last night developed a ringing/rattling sound only in 5th gear. The noise doesn't really change when 5th gear is under load or not.

Does this sound like a 5th gear nut problem and what have you found to be a good fix for this. I really don't have much money to throw at it and I'm told my tranny doesn't have many miles on the rebuild. I know some have welded the nut on with great results but also know that sometimes the welds break and then you must install a new shaft.

What are your thoughts, Thanks

Yeah, I had 5th gear issues where getting it into 5th was like getting in an arm wrestle with the shift lever. Also had them where 5th gear screamed like crazy. NV4500’s are weird because some make more “normal” noises than others. Curious how many NV4500’s you’ve driven to compare this as a normal characteristic or something out of the ordinary. NV4500’s are finicky!

Funny you should bring this up as I just got a reman NV4500 for the Polar Bear about 3 weeks ago. The new one shifts fine but it makes a huge racket in 5th gear…not under acceleration or coast but a coast with a slight tip in of the throttle. Hard to explain the noise but it sounds like something inside is loose. The closest thing I’ve ever heard to a noise like this is when the idler gear in the NP205 in the K10 was loose and would bounce around under a slight tip on of the throttle on a partial coast when the gears are somewhat relaxed. I’ve been going round and round with the reman company where they said “No problem….ship it back and we’ll take a look”. And I’m like nooooo…..you guys send me another one so I don’t have to have my shop plugged with the Suburban for 3 weeks while this one gets shipped back, they take a look/fix then ship it back. They aren’t willing to send me another unless I pay for it then they will reimburse me once they tear into it and confirm a defect on their part. That leaves me in an awkward position with $1000 on the line hoping they will be honest and own up to an issue rather than pull some shenanigans that reman companies are famous for pulling. I guess they’ve been burned before where they won’t ship anything until they confirm the issue is theirs and not an installation error. There is no error even a moron could do with the installation that would cause this noise other than something went wrong during their rebuild. Very frustrating.

I tell ya, I am done with NV4500’s after this mess gets resolved. The next NV4500 that dies in the K10 or this burb is getting replaced with something else even if it is an automatic. Tremec makes an equivalent transmission to a NV4500 (similar dimensions, same input and output spline size and counts) that is used in Mexican and South American market GM trucks but we never got them in the US. Tempted to see what it would take to get one of those…..or just go 4L80E next go around. I’m in a real bad mood about NV4500’s lately

[Chevy3+3]

Originally Posted by DirtyLarry

Yeah, I had 5th gear issues where getting it into 5th was like getting in an arm wrestle with the shift lever. Also had them where 5th gear screamed like crazy. NV4500’s are weird because some make more “normal” noises than others. Curious how many NV4500’s you’ve driven to compare this as a normal characteristic or something out of the ordinary. NV4500’s are finicky!

Funny you should bring this up as I just got a reman NV4500 for the Polar Bear about 3 weeks ago. The new one shifts fine but it makes a huge racket in 5th gear…not under acceleration or coast but a coast with a slight tip in of the throttle. Hard to explain the noise but it sounds like something inside is loose. The closest thing I’ve ever heard to a noise like this is when the idler gear in the NP205 in the K10 was loose and would bounce around under a slight tip on of the throttle on a partial coast when the gears are somewhat relaxed. I’ve been going round and round with the reman company where they said “No problem….ship it back and we’ll take a look”. And I’m like nooooo…..you guys send me another one so I don’t have to have my shop plugged with the Suburban for 3 weeks while this one gets shipped back, they take a look/fix then ship it back. They aren’t willing to send me another unless I pay for it then they will reimburse me once they tear into it and confirm a defect on their part. That leaves me in an awkward position with $1000 on the line hoping they will be honest and own up to an issue rather than pull some shenanigans that reman companies are famous for pulling. I guess they’ve been burned before where they won’t ship anything until they confirm the issue is theirs and not an installation error. There is no error even a moron could do with the installation that would cause this noise other than something went wrong during their rebuild. Very frustrating.

I tell ya, I am done with NV4500’s after this mess gets resolved. The next NV4500 that dies in the K10 or this burb is getting replaced with something else even if it is an automatic. Tremec makes an equivalent transmission to a NV4500 (similar dimensions, same input and output spline size and counts) that is used in Mexican and South American market GM trucks but we never got them in the US. Tempted to see what it would take to get one of those…..or just go 4L80E next go around. I’m in a real bad mood about NV4500’s lately

Sorry to hear your having sucl trouble from the transmissions. This is actually the first NV4500 I have driven. The shifts are great. I have no problem grinding during shifts or anything like that. It's a funny noise like a light pinging/rattle. It's not extremely loud. Makes me wonder if it might be normal noise. The last time I drove it I could not get it to duplicate the noise. I'm getting ready to change the oil in it (ouch $$$), lol. I've read somewhere to add an extra quart through the shift tower to properly lubricate the input bearing. After I change the oil I will just drive it and see what happens. I have to admit you have me a little worried about the NV4500. I was excited about it until your last comment, lol.

[DirtyLarry]

Originally Posted by Chevy3+3

Sorry to hear your having sucl trouble from the transmissions. This is actually the first NV4500 I have driven. The shifts are great. I have no problem grinding during shifts or anything like that. It's a funny noise like a light pinging/rattle. It's not extremely loud. Makes me wonder if it might be normal noise. The last time I drove it I could not get it to duplicate the noise. I'm getting ready to change the oil in it (ouch $$$), lol. I've read somewhere to add an extra quart through the shift tower to properly lubricate the input bearing. After I change the oil I will just drive it and see what happens. I have to admit you have me a little worried about the NV4500. I was excited about it until your last comment, lol.

It could very well be a normal noise. Run it by a trans shop and have them listen to it before you start getting worried. They do make some normal noises and some make more noises than others. Even the ZF 6 speed in my Silverado has made a noise like an alligator gurgling rocks since the truck was brand new. If you’re getting some vibrations to go along with the noise like I am getting with my new reman 4500 then that is a different story.

[Chevy3+3]

Originally Posted by DirtyLarry

It could very well be a normal noise. Run it by a trans shop and have them listen to it before you start getting worried. They do make some normal noises and some make more noises than others. Even the ZF 6 speed in my Silverado has made a noise like an alligator gurgling rocks since the truck was brand new. If you’re getting some vibrations to go along with the noise like I am getting with my new reman 4500 then that is a different story.

What type of vibrations are you getting. I do have a light occasional vibe I notice in 3rd & 4th gear at a certain RPM. Mostly a high RPM like 25-2800. Which is past my normal shift RPMs for a 454. If I push the RPMs closer to 3000 them my vibration goes aways. My flywheel is new along with my clutch and pilot bushing.

[DirtyLarry]

Originally Posted by Chevy3+3

What type of vibrations are you getting. I do have a light occasional vibe I notice in 3rd & 4th gear at a certain RPM. Mostly a high RPM like 25-2800. Which is past my normal shift RPMs for a 454. If I push the RPMs closer to 3000 them my vibration goes aways. My flywheel is new along with my clutch and pilot bushing.

The vibration on mine coincides with the noise… coast with slight tip-in of the throttle in 5th gear when the gears aren’t under load. The fussy shifting 5th gear NV4500 core that I shipped them did not do this nor does the one in the K10 but the old one I pulled out of the K10 a few years ago before it got a new one had a 5th gear that knurled the mainshaft did make a similar noise and vibration. I suspect the reman shop did not replace the 5th gear or mainshaft in this so called reman, just added new bearings, synros, and 5th gear nut fix. Even with a retightened 5th gear nut if the mainshaft is knurled the 5th gear will rock on it and make noise/vibration. I think that is what I wrong with this “reman”. Zoomad rode in it yesterday and he was like….. “wholly @#%K”

On yours I suggest having a trans shop listen to it. The noise could be normal and the vibration may not be related. It still seems odd you added that AA spacer and didn’t have to adjust driveline lengths. Your vibration may have nothing to do with the noise but more related to adjustments needed due to the swap itself.

[83GMCK2500]

The variety of NV4500 experience is good to hear. I own two, one is on the road, other waiting for bearing kit and mainshaft swap to 4WD. To my knowledge the one in the '96 has never been rebuilt, 293,### miles and the wear in the shift tower and general transmission behavior reflects that. Once it's warmed up it might as well not have syncros, I do a lot of double-clutching when the oil is hot. In the past month or so it's developed a howl in 5th at 60+ MPH, it howls over tires, it howls over the radio, and it's only while under drive, if I go down a good enough hill (with cruise set) or let off it quiets in an instant. Feather the throttle and it chirps out a howl in relation to drive from coast.

I'd like to find a shop that knew these intimately enough to go through both of mine.

Larry, your ZF description has me laughing at my desk, not only the mental picture but the accuracy of it.

[68Timber]

Dang, I'm surprised and a little disappointed to hear this. All you normally hear is praise for them.

[argonaut]

Are you guys running the press fit damper on your output shaft?

[Zoomad75]

Yeah I heard the noise this weekend. Odd to say the least. It's only on light load, tip in of the throttle in 5th. Which, because of the wide flat torque curve of the 8.1 could happen at 30 mph or higher. The faster it's going the worse it sounds though. Similar to putting a few golf balls in a blender and hitting Frappe. A little more muted, but rough none the less.

Normally I've got a higher tolerance for noises than Larry does (or higher amount of hearing loss), but at highway speeds it's downright obnoxious. The only way to make it stop is to completely let off the throttle or keep your foot in it. Driving either way would be annoying. Anything that makes that vibration along with the noise can't be good for itself long term.

[Chevy3+3]

Well I drained out my trans oil which didn't look fantastic. It was darker in color. When I put the transmission in I filled the oil until it ran out the fill plug. I drained almost 4 qts from it today. I started adding oil through the fill plug on flat ground and only managed to get about 3.75 qts into it before it ran our the fill plug hole. I added an extra quart through the shift tower and got it out on the road. The shifting is smoother and it did quiet the trans down some. Now I can't get 5th gear to make any noise. Only sounds from the trans now I would consider normal.

[68post]

Originally Posted by Chevy3+3

Well I drained out my trans oil which didn't look fantastic. It was darker in color. When I put the transmission in I filled the oil until it ran out the fill plug. I drained almost 4 qts from it today. I started adding oil through the fill plug on flat ground and only managed to get about 3.75 qts into it before it ran our the fill plug hole. I added an extra quart through the shift tower and got it out on the road. The shifting is smoother and it didn't quiet the trans down some. Now I can't get 5th gear to make any noise. Only sounds from the trans now I would consider normal.

What are you using for fluid ? Because they are extremely picky about their fluid. Amsoil ? GM/Dodge trans fluid ?

I'm having a problem that may not relate to my NV4500, but it would have to be the transfer case if it isn't the trans ( I need to search the web again to refresh myself of the NV4500's problems and their symptoms).
http://67-72chevytrucks.com/vboard/s...d.php?t=697706

[Chevy3+3]

Sorry in my above post I said didn't help with noise. I corrected it now saying changing the fluid and overfilling DID help with smoother shifting and help make it quieter

[Chevy3+3]

Originally Posted by 68post

What are you using for fluid ? Because they are extremely picky about their fluid. Amsoil ? GM/Dodge trans fluid ?

I'm having a problem that may not relate to my NV4500, but it would have to be the transfer case if it isn't the trans ( I need to search the web again to refresh myself of the NV4500's problems and their symptoms).
http://67-72chevytrucks.com/vboard/s...d.php?t=697706

After reading countless articles about the oil I determined that no one has had any problems with the Amsoil MTG 75-90. My GM dealer wanted $30/quart for the recommended oil #12346190. I chose to put in the Amsoil as I read lots of people having great luck with it. I got it bought for $12.31/quart. When I got the bottles of Amsoil it says on the bottle that it is a direct replacement for GM #12346190.

That's good enough for me. Only time will tell. I may buy some more and run it iny np205 t-case.

By the way.....I didn't mean to hi Jack Dirty Larry's thread. If anyone has any questions for me please PM me and not post here. I want this thread to remain Larry's and his badass Polar Bear Suburban.

[Lmac]

Originally Posted by DirtyLarry

Yeah, I had 5th gear issues where getting it into 5th was like getting in an arm wrestle with the shift lever. Also had them where 5th gear screamed like crazy. NV4500’s are weird because some make more “normal” noises than others. Curious how many NV4500’s you’ve driven to compare this as a normal characteristic or something out of the ordinary. NV4500’s are finicky!

Funny you should bring this up as I just got a reman NV4500 for the Polar Bear about 3 weeks ago. The new one shifts fine but it makes a huge racket in 5th gear…not under acceleration or coast but a coast with a slight tip in of the throttle. Hard to explain the noise but it sounds like something inside is loose. The closest thing I’ve ever heard to a noise like this is when the idler gear in the NP205 in the K10 was loose and would bounce around under a slight tip on of the throttle on a partial coast when the gears are somewhat relaxed. I’ve been going round and round with the reman company where they said “No problem….ship it back and we’ll take a look”. And I’m like nooooo…..you guys send me another one so I don’t have to have my shop plugged with the Suburban for 3 weeks while this one gets shipped back, they take a look/fix then ship it back. They aren’t willing to send me another unless I pay for it then they will reimburse me once they tear into it and confirm a defect on their part. That leaves me in an awkward position with $1000 on the line hoping they will be honest and own up to an issue rather than pull some shenanigans that reman companies are famous for pulling. I guess they’ve been burned before where they won’t ship anything until they confirm the issue is theirs and not an installation error. There is no error even a moron could do with the installation that would cause this noise other than something went wrong during their rebuild. Very frustrating.

I tell ya, I am done with NV4500’s after this mess gets resolved. The next NV4500 that dies in the K10 or this burb is getting replaced with something else even if it is an automatic. Tremec makes an equivalent transmission to a NV4500 (similar dimensions, same input and output spline size and counts) that is used in Mexican and South American market GM trucks but we never got them in the US. Tempted to see what it would take to get one of those…..or just go 4L80E next go around. I’m in a real bad mood about NV4500’s lately

Comment only for my future reference

[jkiersh2]

I have just started down the L18 road. What I am doing is a little different than the folks on this forum are doing but this looks like the best place to ask the questions.
My tow vehicle is a 1999 GMC PU with the 6.0L and broken exhaust manifold studs.
I just picked up a 8.1 that I just pulled out of a 3/4 ton van. What the motor has is all of the accessory hardware that is desirable if this was going into an older truck. So the question is do keep this configuration or convert to the correct setup my truck was optioned for. I am inclined to convert and possibly trade my brackets for the more common versions.

[DirtyLarry]

Originally Posted by jkiersh2

I have just started down the L18 road. What I am doing is a little different than the folks on this forum are doing but this looks like the best place to ask the questions.
My tow vehicle is a 1999 GMC PU with the 6.0L and broken exhaust manifold studs.
I just picked up a 8.1 that I just pulled out of a 3/4 ton van. What the motor has is all of the accessory hardware that is desirable if this was going into an older truck. So the question is do keep this configuration or convert to the correct setup my truck was optioned for. I am inclined to convert and possibly trade my brackets for the more common versions.

Welcome to the forums!

On a GMT800 you could use either brackets but if you plan to use OEM A/C lines you would be better off using the GMT800 brackets (low mount A/C compressor). You shouldn’t have any problem finding someone to trade brackets with you as the van/medium duty brackets are the most desirable for swappers. If you haven’t already joined the group, there is a nice group on Facebook called the “8.1L Info Swap Classifieds”. Lots of guys there always looking for brackets and Ed over there has done a couple L18’s in GMT800 trucks.

Also, if you have already found it…. I put together a complete thread on all things 8.1L HERE

Good luck with you project..

[silverbear]

Larry, I was directed to your build while searching for answers in Crocky125 thread about parking brakes. Looking at your pics of the 9.5" semi-float rear you had in the Suburban, the parking brake cable for the passenger side enters the backing plate on the rear side of the axle tube. On the 14FF you installed, the passenger side cable enters the backing on the front side of the baking plate. My questions are: 1. Was the cable for the semi-float original to your Burb? 2.Did you use the same cable on the Full float as was on the semi-float?

I swapped in a 1999 14FF with 13"slip on drums into my 1986 K10 and I am having a little trouble with the parking brake hanging up on my passenger side. Not sure yet if it my cable routing, the way a connected it to my system of if it is the cable I purchased to use. Just looking for resources and/or options.

[DirtyLarry]

Originally Posted by silverbear

Larry, I was directed to your build while searching for answers in Crocky125 thread about parking brakes. Looking at your pics of the 9.5" semi-float rear you had in the Suburban, the parking brake cable for the passenger side enters the backing plate on the rear side of the axle tube. On the 14FF you installed, the passenger side cable enters the backing on the front side of the baking plate. My questions are: 1. Was the cable for the semi-float original to your Burb? 2.Did you use the same cable on the Full float as was on the semi-float?

I swapped in a 1999 14FF with 13"slip on drums into my 1986 K10 and I am having a little trouble with the parking brake hanging up on my passenger side. Not sure yet if it my cable routing, the way a connected it to my system of if it is the cable I purchased to use. Just looking for resources and/or options.

You’re right, on the original semi floater the brake cable enters the backing plate from the rear on the pass side and front on the driver’s side (the backing plates are symmetrical where they are the same part number for both sides). On the 10.5” 14FF with the 84 and later push in type cable, the cable enters the backing plate on the front on both sides.

The 99 axle could have entirely different backing plates being it is from a newer body style than what I have but if it helps, below are the Napa park brake cable part numbers I used on the Polar Bear. If I recall correctly, I used an 89 R2500 (2wd) w/7.4L as the application as those came factory with 10.5” 14FF’s and was a direct plug and play for my Burb. Might not be the case on your truck with a later body style axle. You could look at other 1 ton trucks and van's with 14FF and look at their dimensions to see if they would fit your K10 better than the part numbers below. There are few different lengths of cables out there for the 84 and later 14FF's.

93253 Parking Brake Cable - Left Rear, 55.5; Rear Left
93254 Parking Brake Cable - Right Rear, 77.81; Rear Right

You can barely see here where the passenger’s side cable crosses the axle and is tied to the top pinion bolt with a p-clamp. That is the way the 2wd Suburban’s with full floaters were routed….at least the one I saw at the boneyard anyway.