5 speed conversion with pics

[jodydewey]

Everyone,

I have started to convert my 1968 Chevy C10 shortbed from an automatic back to a stick. The transmission I decided to use was a NV3500 five speed from a 1994 Chevy C1500 pickup. I am going to document all the steps needed and the changes required to install this into my pickup. My truck was originally a 3 speed on the tree truck but had been converted to a TH350. The clutch pedal was hidden beneath the carpet (a nice surprise). When I started having transmission trouble I decided it would be more fun to go back to being a stick.

The first area I chose to change was the clutch linkage. The truck was originally made with mechanical linkage. The NV3500 uses hydraulic linkage. Mechanical cannot be retrofitted because the NV3500 has the clutch fork on the passenger side.

[jodydewey]

I purchased a hydraulic clutch kit from LMC for a 1994 Chevy 1500 truck. It comes with a hydraulic master cylinder, the line, and a slave cylinder. The units are assembled, filled, and bled already so bolting it in is all that is required.

[jodydewey]

The hydraulic master cylinder has to be level to work properly so the clutch rod could not be used in its present form. You may notice that the lever points down at about a 30 degree angle. This would have to change. Basically the "clock" of the lever had to change from 5 oclock to 3 oclock.

[jodydewey]

Basically there are two different thoughts: make a bracket to change the angle or - (the way I am going) cut off the shaft, rotate it, and weld it back on. I wanted it this way so that I could make it look like that was the way it was supposed to be instead of something I cobbled together. Here are the pictures of the clutch pedal before and after welding. The first picture is of the pedal assembly in the truck. Notice the angle of the bracket. The second is of the pedal in my vice. Notice the sharpie mark on the shaft. This is the angle the assembly needs to be at to work with the new hydraulic master cylinder. The next one is the pedal after I cut off the shaft and tack welded it in the correct position. The last two are of the bracket after it was tack welded.

[Huck]

Is the trans manual speedo with cable gear or elec pulsed? that was my problem with a 96' 5speed.

[jodydewey]

It is electric pulse. My plan is to switch the gage cluster to the cyberdyne blue ice gages. The cool thing about the cyberdyne setup is that you turn it on with the parking lights on and it will enter set mode. Then you bring the truck up to 45 mph and hit the set button. Then the speedo is set. No other calibrations needed. I have one in my 1990 Nissan 240sx. I used a handheld GPS to set it. Since it is so easy to set it will work with any tire/gear combination easily.

[chevybill]

mdlackey, i am also using a nv3500 and my original 6 cyl crossmember could not be used. I have an auto crossmember which attaches to the rear part of the tranny just like an automatic. The original 6 crossmember does not drop low enough in the middle to this tranny with the original crossmember.

[jodydewey]

I would love to see pictures of everyone elses conversion so I can see some stuff I haven't done yet. Pictures of interest would be the in the cab shots with the hole for the shifter measurement from the center front of the hump. I also agree about the crossmember. I will be using an automatic crossmember since that is what I have. I didn't even think about the height so thank you for that! I will check the angle with my handy dandy angle finder when I put in the tranny. Hopefully it will be 0 degrees. I also don't know about the driveshaft yet. My NV3500 came with the yoke of the old driveshaft and a piece of the old driveshaft. I haven't checked to see if the TH350 yoke and the NV3500 yoke are the same one. I will be putting the transmission/engine in this week for a test fitting. Hopefully all will go well. I will post some pictures.

[7387chevys]

How much does the clutch linkage cost?What about an nv4500 would it be the same for the swap?
Shane

[jodydewey]

Originally Posted by 7387chevys

How much does the clutch linkage cost?What about an nv4500 would it be the same for the swap?
Shane

The clutch linkage cost me if I remember about $200 from LMC. I bought the hydraulic master, slave, and tubing all as a kit for a 1994 GMC 1500.


As for the NV4500 asked earlier, they are generally the same price I paid for in the junkyard and are more plentiful. If you are looking for an NV4500 look for a 4WD S10 with a 4.3L Chevy. It is the exact one you will need. The NV3500 is for 2WD, NV4500 for 4WD.

[BUDDY]

Originally Posted by jodydewey

If you are looking for an NV4500 look for a 4WD S10 with a 4.3L Chevy.

Where'd you get that information?

No S-10 ever came with the NV4500. The NV4500 is a HD (big) transmission for 3/4 & 1-ton applications. They are the transmissions that replaced the SM465 4-sp from the 3/4 & 1-ton trucks & added an OD gear. They were pu in behind the cummins diesel on dodge trucks & the big block & 6.5 TD in GM products. They can handle about 450 hp & 500 lb-ft in stock trim.

An NV3500 is a good candidate for this swap, but it's limit is about 250 hp/300 lb-ft. They did come in the S-10, but I'm not sure what years.

Also, the NV4500 has a separate bellhousing, whereas the NV3500 has an integral bellhousing.

HTH,

Buddy

[mdlackey]

Chevybill, which auto x-member did you end up using? Do you have pics of the final install that you could share?

Jody, any new updates on your status?

Thanks,
Dave

[chevybill]

My crossmember came from www.performanceonline.com. I purchased tubular engine mounts and the crossmember at the same time.
I have no pics, truck is still in building stage and I am trying to figure out how I am going to make clutch linkage work.

[mdlackey]

Any of you, doing this NV3500 conversion, have plans for a speedo connection? Believe that the NV3500 has an electric speedo connection, while our original trannys had mechanical cable connection.

Would like to stay with a "mechanical" connection, since I have parts for a cruise setup, but may be easier to go to an electronic setup ...

Thoughts?

Dave

[chevybill]

mdlackey, That looks really good, I have a later transmission that does not have the separate slave cylinder down on the bellhousing. I have to come up with a bracket that holds the actuating cylinder in the same location that you mounted your clutch master cylinder.

Have you driven your truck yet with this clutch setup?

As far as speedometer, I am using an electronic autometer speedo that is supposed to work with this tranny. Autometer 1405 designer black series.

[mdlackey]

Nope, haven't driven it, yet ... really concerned about what I'm going to have to do for the proper clutch articulation. Sounds great, thought, with just headers ...

Had driveshaft shortened, but it may not have been enough ... may need another 1/2" or so. Just too tight, when trying to mount back in to place. The "longer" one was the original, and it was shortened by about 6". The "shorter" one was from the '94 truck, and was TOO short. Plus, you'll see the difference in the end splines, where the intermediate shaft mates up with the rear driveshaft ... 10 spline versus ?? spline (27?) ...

Anybody figured out the "hump" over the tranny yet?

Dave

[chevybill]

Have you engaged your clutch yet and changed gears with the engine running? Do you have the clutch fully operational yet?

I was able to use my original driveshaft. Engine is in V-8 position, I was able to use my original yoke as well no cutting what so ever.

[watahyahknow]

you might want to try to find a smaller diameter clutchmaster from somewhere else so you need more travel to shift the same amount of hydraulic fluid , that should solve the exessive force needed to push the pedal down too

[jodydewey]

Guys, sorry it took me so long to reply to some of these - I have been doing extensive rework on my radiator core support. Now that it is done I will be putting the engine and transmission into the truck for final measurements. So far I know the NV3500 is 7 inches longer than a TH350 from the mount so I am estimating that the crossmember will have to come back that far. Thanks for the info about the height using an automatic crossmember. I think I will make my own crossmember so I can set the output degrees to zero like it should be. I haven't even looked at the driveshaft yet so I don't know what kind of work I will have to do there.

As far as I was told, the NV3500 was in full size pickups and S10s with a 4.3L from 1992 to 1998. The NV4500 is a 4WD transmission. Here is a link if you want more info on it. http://www.nv4500.com/

[mdlackey]

I'm having my own x-member fabricated, as well. If you guys know of a way to 0 the angle of the intermediate shaft to the carrier bearing, I'm all ears ... I'll take some pics, tomorrow, after I have my fab-ed one in place. Having to have my draveshaft cut another 1", as it sits way too far back in the carrier bearing mounting position. So roughly 7" would've been the total length removed from the original driveshaft.

For S&'G's, last week, I placed my stock original x-member in the framerails, just to see how the tranny would sit ... seemed way too low.
I'm really having to think about moving the master cylinder further up the firewall, so that more travel with greater leverege is seen.

On a side note, I cut my tranny "hump" to accomadate the new position of the shifter. Outside of the very top of the shifter housing ... the part I cut to clear ... there aren't any other "clearance" problems. Having a patch plate welded over the old hole, tomorrow.

New pics from anyone else?

Dave

[mdlackey]

Well, I'm looking for feedback/direction ...

Below are pics of my drive angle ... YES, the intermediate shaft is too short by about 3/8" minimum ... the carrier bearing mount is at the very front of the mounting holes of the frame support. Also, you can see that the shaft is at an upward angle from that bearing mount. Looking at the angle of the front U-joint, right behind the tranny output shaft "mount", the wngle isn't too bad ... pretty straight .. might be able to drop it down a little more.

My question is ... would you rather have a front u-joint angle or one held by the rubber of the carrier bearing? Or is a redesign all together?

For those who were looking, you can see the tranny hump and shifter coming through it ...

Anyone thouhts, feedback, or updates on your own projects would be appreciated ... there are enough of us out here!!!

Dave

[mdlackey]

... and the gear shifter pic ...

Did I mention before that my truck is kind of a "beater"? Working on the "mechanics" before the "asthetics" ...

Dave

[mdlackey]

Well, I had to have a new length of "pipe" made for my prop shaft, since I mis-measured the 2nd cut. The initial cut of my original prop shaft (roughly 6") was about right ... should've been about 5 1/2" total.

HOWEVER, my NV3500/MG5 tranny came out of a '94 GMC 1500 ... the "front"/prop shaft u-joint, right behind the tranny needed to measure 3 5/8" x 3 5/8". My 68's u-joint was 3 5/8" x 3 3/4". Seemed to be a difference between the '94 Chevy and the '94 GMC, but could've been a mis-quote of part number and part ...

3 5/8" x 3 5/8" u-joint: PDQ part # 2-0053 (Pep Boys)
U-joint strap kit: NAPA part # 260-4178

Now, I have to try and get my drive angles within spec. Believe that I may have to use a spacer to raise the carrier bearing, rarther than lower the rear of the tranny ... starts to put a real angle on the prop shaft and believe that it will start to stress the engine mounts, too.

Anyone know if a return spring ... or anything for that matter ... was used on the VN3500/MG5 trannys to keep the throwout bearing off of the pressure plate spines?

Pics to follow ...

Thanks,
Dave

[mdlackey]

Update ... Drilled and bolted the x-member into place and tigtened the u-joint straps on the prop shafts u-joints. Was able to drive the truck around the block today. Outside of the EXTREMELY short clutch throw that I mentioned in a posting earlier, it drove well.

Outstanding concerns ...

1. EXTREMELY short clutch throw
2. Drive line angles

Anyone have thoughts?

Dave

[454_72_4X4]

Originally Posted by mdlackey

Update ... Drilled and bolted the x-member into place and tigtened the u-joint straps on the prop shafts u-joints. Was able to drive the truck around the block today. Outside of the EXTREMELY short clutch throw that I mentioned in a posting earlier, it drove well.

Outstanding concerns ...

1. EXTREMELY short clutch throw
2. Drive line angles

Anyone have thoughts?

Dave

The extremely short clutch throw is probabl due to the master cylinder rod pivot point being too far from the clutch pedal point.
I'm going to be converting to hydro clutch, (nv4500 soon), and the best way I've come up with to get the correct length for the pivot point is to measure the stock clutch pedal out of say, a 94 Chevy with a manual trans and hydro clutch.
I haven't gotten around to finding one to measure yet though.

The drive line angles...I didn't read all the posts, (yet), but I did see somebody mentioned 0 degrees. I don't think that would be correct.
The crankshaft centerline isn't "level" when an engine is installed. The carburetor pad should be level, or close to it.
The important thing on driveline angles is that the transmission output shaft angle matches the rearend pinion angle. Or as close as possible.