Had to trailer my truck home today. Convertor or 700r4 problems.

[suspect]

I'll try and give all the information and scenarios I can think of.

700r4 (1989 model) with a Hughs 2500 Lockup Stall Convertor behind a 383.

I personally did the full rebuild of the transmission. I did the usual upgrades: beast sunshell, boost valve, servo, shift kit, etc.
After the trans was finished being built, I mounted it to the engine and sat them on the frame. After 9 months, I did the first start on the engine. I didn't have the TV cable hooked up nor did I kick the trans into gear. For the next 5 months, I only started the engine for testing for a total of about 30-40 min run time. After a total of about 14 months, I set the TV cable and kicked the trans into gear. It went into reverse and through all the gears just fine. For 3 months, I drove around little trips not to far from home because I didn't have a way to lock up the convertor. I put about 50 miles on it at this point.

I finally installed a Painless Lockup Wiring Kit. It came with the vaccum switch for lock up. I was having the issue with it constantly locking/unlocking and the vacuum delay that is recommended for this problem is discontinued. So, I cut off the vacuum delay switch and wired up a toggle switch. Once I get up to 50-55 mph, I flip the switch and I could see that the convertor would lock and my rpm's would drop 200/300 rpm. Once I started braking, I would flip it to unlock. If I floored it, it would downshift and work fine.
I've put 198 miles on the odometer doing it this way. The only issues I've noticed is once in a while when I'm pulling in/out of the garage or parking, I would hear a somewhat loud ticking noise from the trans, something like the fins in the convertor hitting something. And the other issue is sometimes when I come to a stop or just let off the brake, their would be a rough jarring in the drivetrain. Like their was slack somewhere between the trans and axle and had a strong banging or nudging. Once I hit about 140 mi on the OD, I noticed it wasn't really shifting as strongly. It was slipping into gear. If I got on it from a stop, the rpms would rap out and I would have to let off the gas to let it shift.

So, today I left work and I got on it a little. It shifted from 1st to 2nd, then just revved up. And that is all I have now, 1st, 2nd, and reverse. From a stop, it will shift from 1st to 2nd just fine, but nothing else. The rpms just rev up if I give it any gas, I can creep about 20 mph. Goes into reverse fine also.

I'm thinking I screwed up by not doing a proper convertor break-in or my method of locking up the convertor is wrong.

Any ideas?
Thanks, Daniel

[clinebarger]

3-4 clutches are Done, Nothing to do with the converter or converter clutch. The jarring & banging may be a 2-3 or 3-2 tie-up...This will burn 3-4 clutches.

[Blue Rat]

I would clean the converter before you install it again.

[cableguy0]

Being a lockup converter with clutches inside. Any material that went through the unit is embedded in the lockup clutches. The converter should be rebuilt or replaced. I wouldn't trust flushing it. The only thing to do at this point is to yank out the transmission and tear it down.

[suspect]

Thanks guys. I'm going to pull it tomorrow. I'll open it up Wed & Thurs.

[suspect]

This thing is fried. There's no friction material left. Just looks like a stack of steels. The 2/4 is on it's way to toast also.
On the first disassemble, I wrote down; 6 frictions (.080") & 5 steels (.075") w/.098" clearance.
I assembled with; 8 frictions (.060") & 7 steels (.060", & one .075") w/.041" clearance.
I can't remember how I came up with going with that clearance, but that's what I did.

Should I just move on from trying to be clever and follow the stack ups in the ATSG manual?
This is as far on tear down I got tonight. I'll post up anymore damage tomorrow once I get that far.

[clinebarger]

2-3, 3-2 Tie-Up issues for SURE. Anytime a Tie-up between these 2 frictions happens it will burn frictions, Your upshifts go like this 1-2, 2-4, 4-3, 3-4, The downshifts are more noticeable as a bang, clank, release feeling.

[suspect]

Originally Posted by clinebarger

2-3, 3-2 Tie-Up issues for SURE. Anytime a Tie-up between these 2 frictions happens it will burn frictions, Your upshifts go like this 1-2, 2-4, 4-3, 3-4, The downshifts are more noticeable as a bang, clank, release feeling.

What would cause the 2/4 band to engage and never release? I got the rest of it disassembled and every stack (except the one pictured) looks close to new.
I can understand if that stack burned up because of to tight of clearance, but I'm not sure on how the band plays into it and didn't disengage.

Thanks.

[suspect]

Maybe I shouldn't say the band never released. I'd just like to correct what I did wrong.

[clinebarger]

Originally Posted by suspect

What would cause the 2/4 band to engage and never release? I got the rest of it disassembled and every stack (except the one pictured) looks close to new.
I can understand if that stack burned up because of to tight of clearance, but I'm not sure on how the band plays into it and didn't disengage.

Thanks.

Originally Posted by suspect

Maybe I shouldn't say the band never released. I'd just like to correct what I did wrong.

How was the Band & 3-4 clutches when you first tore it down, Trying to figure out if this was pre-existing or something you did?????

Shift kit Brand & Part#?
Spacer plate hole sizes? Particularly the 2nd & 3rd feed holes.
2nd servo type?
Did you replace the 3rd Accumulator Check Ball capsule behind the Servo in the case?

On a 1-2 shift, The 2-4 Band applies via the 2nd piston in the servo.
2nd feed oil is "on" in every gear but 1st & Reverse, But the Band needs to be released in 3rd gear. 3rd oil enters behind the servo & Pushes the band off while simultaneously applying the 3-4 clutches for a 2-3 shift. The Timing of the Release & Apply has to be perfect. A Bind/Tie-up or Flare will result if timing is off.

More info... Check the 2nd piston seal for nicks/tears/rollover (arrow)

[suspect]

I bought the trans off craigslist. I did a 100% rebuild (every ring, seal, gasket, bushing, etc.) I saved everthing because it all still looked really nice. The only thing I noticed wrong was a broken 3-4 accumulator spring.

The 3-4 clutch plates and band are toast. Everything else looks fine.

I rebuilt with the TCI pro super kit 378900
Vette servo from pro built 700CVS
TCI shift kit 376000 http://static.summitracing.com/globa...tci-376000.pdf

In my ATSG manual, on the case side
55E 3-4 clutch/3-2 ex. I have a check ball (plate hole size .200")
55H part throttle/drive 3. I have a check ball (plate hole size .200")
55F 2nd/1-2. I don't have a check ball (plate hole size .200")

I only have 2 check balls on the valve body side. I don't know what the location is called, but you can see them on the shift kit link.

I did the street plus mod, added a 1/4" allen screw in the case of the 3-4 accumulator piston bore.

I didn't touch the 3rd accumulator check ball capsule in the servo bore. It looks like about a .010"-.015" hole. There's not check ball. Is there supposed to be a check ball there?

The second servo piston seal looks good.

I appreciate you taking the time to look into this issue.

[suspect]

I think I'll put the stock servo back in. I'm open to suggestions if I should run a different shift kit or put it back to stock?

I picked up my convertor from the trans shop yesterday. They opened it and cleaned/inspected. They said everything looks good inside.

[clinebarger]

Originally Posted by suspect

I bought the trans off craigslist. I did a 100% rebuild (every ring, seal, gasket, bushing, etc.) I saved everthing because it all still looked really nice. The only thing I noticed wrong was a broken 3-4 accumulator spring.

The 3-4 clutch plates and band are toast. Everything else looks fine.

I rebuilt with the TCI pro super kit 378900
Vette servo from pro built 700CVS
TCI shift kit 376000 http://static.summitracing.com/globa...tci-376000.pdf

In my ATSG manual, on the case side
55E 3-4 clutch/3-2 ex. I have a check ball (plate hole size .200")
55H part throttle/drive 3. I have a check ball (plate hole size .200")
55F 2nd/1-2. I don't have a check ball (plate hole size .200")

I only have 2 check balls on the valve body side. I don't know what the location is called, but you can see them on the shift kit link.

I did the street plus mod, added a 1/4" allen screw in the case of the 3-4 accumulator piston bore.

I didn't touch the 3rd accumulator check ball capsule in the servo bore. It looks like about a .010"-.015" hole. There's not check ball. Is there supposed to be a check ball there?

The second servo piston seal looks good.

I appreciate you taking the time to look into this issue.

Originally Posted by suspect

I think I'll put the stock servo back in. I'm open to suggestions if I should run a different shift kit or put it back to stock?

I picked up my convertor from the trans shop yesterday. They opened it and cleaned/inspected. They said everything looks good inside.

I'm interested in these hole sizes, I hope the .200" hole sizes are check ball hole sizes not Feed hole sizes?
2nd feed hole (45)
3rd CL. Exhaust (46)
3rd feed hole (43)

According to TCI's directions You omit Check Ball 55E & Leave 55F in place, You seem to have it backwards? Recheck please.

This TCI shift kit instructions SUCK, Very murky about plate hole sizes
I have to honest, I have not installed this type of shift kit in over 10 years because of the archaic nature of it, As long as you did NOT block the 1-2 accumulator...It should still work.

Blocking the 3-4 accumulator if fine, I guess 25 years ago, They didn't know you can just install the spring in the case, Then the piston....Effectively blocking the accumulator without mods

http://67-72chevytrucks.com/vboard/s...=634121&page=2 Post# 38 explains the 3rd accumulator check ball, Your talking about the Bleed orifice.

I know you want your truck back on the road, But if you don't find out exactly what caused the failure, It will happen again.

[suspect]

You're right, I mis-typed. I have a check ball in 55F, and not one in 55E. I snapped a photo of the checkballs on teardown.

Going off your diagram:

TCI spacer plate (the one I used)
2nd feed hole 45 .100"
3rd CL EX 46 .100"
3rd feed 43 .160"

The stock plate that came out on very first teardown
hole 45 .090"
hole 46 .073"
hole 43 .070"

I was putting new rings on the accumulators tonight and I realized something. I'm 99% sure I didn't put a checkball back under the aux. valve body. The instructions say to, but I think I missed it. I added a photo of where.
What is the function of that checkball?

[suspect]

I installed the servo and did the leak test on the 3rd acc. check ball this morning. Fluid came out of the bleed orifice but nothing out of the exhaust. Bone dry.

[clinebarger]

Originally Posted by suspect

You're right, I mis-typed. I have a check ball in 55F, and not one in 55E. I snapped a photo of the checkballs on teardown.

Going off your diagram:

TCI spacer plate (the one I used)
2nd feed hole 45 .100"
3rd CL EX 46 .100"
3rd feed 43 .160"

The stock plate that came out on very first teardown
hole 45 .090"
hole 46 .073"
hole 43 .070"

I was putting new rings on the accumulators tonight and I realized something. I'm 99% sure I didn't put a checkball back under the aux. valve body. The instructions say to, but I think I missed it. I added a photo of where.
What is the function of that checkball?

The holes are bigger than I would ever do, The 3rd clutch feed being .160 is ridiculous!! With a large boost valve & the Sewer pipe sized feed hole....No wonder the 3-4 clutch backing plate is broken.

I'm on the fence on using those hole sizes, 46 & 43 need to be matched pretty close for correct 2-3 & 3-2 clutch to clutch timing.

Did you run that wide 2-4 band on the old reverse input drum?

The check ball under the AUX. valve body is for the Forward Clutch, Did you have harsh garage shift into drive? I have never left the #12 check ball out to see if it caused other issues.

Originally Posted by suspect

I installed the servo and did the leak test on the 3rd acc. check ball this morning. Fluid came out of the bleed orifice but nothing out of the exhaust. Bone dry.

Good! Thanks for checking.

What I would do with a 700R4 behind a torquey 383...

Trans-Go 700-P separator plate
Trans-Go SK 700-JR
Sonnax TV boost valve kit 700r4-LB1
Sonnax Smart Tech Input drum 77733-10K with 8 GM .067 Hi-Energy frictions & 7 .095 steels (common 4L60E/4L65E 3-4 stuff)
Stock Hi-Energy 4L60E band & New reverse input drum.
Retain the Vette servo.

[suspect]

I had plans on going to the transmission supply and looking at a transgo kit and their separator plate tomorrow. I feel better about moving in that direction now and tossing that tci plate.
It's nice to actually learn a little something on what to look for on the plates.

I'll pick up the plate and jr kit, and see if they have a sonnax input drum, boost valve, and frictions/steels.

Friday, I already picked up a used/like new reverse drum. It measures 7.021" and is perfectly straight with a scale across it.
Yes, I put a new band on the old reverse drum. I polished it at work on the lathe. It measured 7.020", however you could see a little light with a scale across it. At the time, I was thinking it's just a band, I didn't think it was that bad. But this time around, I want to eliminate all possibilities, so I got a good one.

The shifts into drive were pretty strong. Didn't chirp the tires or anything close to that.

I understand that making a full diagnosis is tough when you're not doing the teardown and rebuilding. And not knowing what someone else has done or modified. So thanks again.

[suspect]

Clinebarger, I picked up the transgo serperator plate and 700-jr kit today. As I was installing the jr kit, I was swapping the spring in the line bias valve to match the boost valve diameter. I pulled the valve out and no spring, but a .875" long rod came out. I now remember the tci kit swaps the spring with the rod.

I just read up on what the line bias valve does, but I still don't have a full understanding on how it affects performance. I don't know how critical these two valves are with each other.
What is your opinion on how this plays into with the .500" boost valve? Is it another piece that helped create the damage that happened?

[clinebarger]

Originally Posted by suspect

Clinebarger, I picked up the transgo serperator plate and 700-jr kit today. As I was installing the jr kit, I was swapping the spring in the line bias valve to match the boost valve diameter. I pulled the valve out and no spring, but a .875" long rod came out. I now remember the tci kit swaps the spring with the rod.

I just read up on what the line bias valve does, but I still don't have a full understanding on how it affects performance. I don't know how critical these two valves are with each other.
What is your opinion on how this plays into with the .500" boost valve? Is it another piece that helped create the damage that happened?

Great Questions!!

TCI/B&M blocks the Line Bias so even if the TV cable/Geometry is off.....The trans will live through warranty. The front pump with be taxed Big Time, Vane pumps are VERY efficient but fragile at the same time.

The Sonnax has linear pressure rise that is better for the pump, It is .496" diameter. .500" boost valves are JUNK!!!

[suspect]

Originally Posted by clinebarger

Great Questions!!

TCI/B&M blocks the Line Bias so even if the TV cable/Geometry is off.....The trans will live through warranty. The front pump with be taxed Big Time, Vane pumps are VERY efficient but fragile at the same time.

The Sonnax has linear pressure rise that is better for the pump, It is .496" diameter. .500" boost valves are JUNK!!!

I'm a little embarrassed to bring this up, but I need to learn what the significance is on this stuff.

I have no freakin idea what I was thinking. I was being as meticulous as I could.
I'm reassembling the servo per the transgo instructions, and they're actually the exact same instructions as the one I already have.
So, I left out the blue spring that is added between the 2nd piston & steel cover. (upgrade needs a blue spring inside the larger spring). I can't remember if I wasn't furnished the blue, but either way, I only had the large one in.
Secondly, I didn't add the large gold ring shim that butts against the cover. I'm pretty sure I didn't receive that ring in the first kit. Looks like the purpose of that, is to move the servo closer to the band for a tighter grip?

Any thoughts on this?

Also, the transgo kit says to reinstall the original spring in the 3-4 accumulator. Should I go ahead and remove the allen set screw that I installed in the bore case side?

[clinebarger]

Originally Posted by suspect

I'm a little embarrassed to bring this up, but I need to learn what the significance is on this stuff.

I have no freakin idea what I was thinking. I was being as meticulous as I could.
I'm reassembling the servo per the transgo instructions, and they're actually the exact same instructions as the one I already have.
So, I left out the blue spring that is added between the 2nd piston & steel cover. (upgrade needs a blue spring inside the larger spring). I can't remember if I wasn't furnished the blue, but either way, I only had the large one in.
Secondly, I didn't add the large gold ring shim that butts against the cover. I'm pretty sure I didn't receive that ring in the first kit. Looks like the purpose of that, is to move the servo closer to the band for a tighter grip?

Any thoughts on this?

Also, the transgo kit says to reinstall the original spring in the 3-4 accumulator. Should I go ahead and remove the allen set screw that I installed in the bore case side?

The Inner Blue spring is to help cushion band apply, It helps with the 1-2 "Bump" at light throttle.
The Gold ring is a shim to get band clearance correct, Install Shim, If you can turn output in BOTH directions....Leave shim in. If not, Take shim out.

4th accumulator....Remove set screw, Install the spring in the case then the piston.

2nd accumulator....Do Not install the TransGo springs in the accumulator. They Break, I promise!!
The TV kit is the most important part of the Shift Kit.
Sonnax Purple spring, Works PERFECT with the Vette servo! http://www.sonnax.com/parts/1660

Stock Accumulator pistons leak....Badly around the pins.
Sonnax Pinless accumulator pistons http://www.sonnax.com/parts/2520

I'm sorry I didn't mention these things earlier.

[RANZTRANZ]

Just want to add one point, when installing the gold shim into servo...assemble the servo without the "blue" O ring on the servo cover into the case....once the clearance is checked on the 2/4 band, remove servo cover and install the "blue" O ring...

[RANZTRANZ]

I see this as a 1989 700r4, which is in what year of a truck ? Was this 700r4 installed in place of a 350 ? If so, how is the TCC engaging and disengaging ? Do you know if the TCC was engaging at all ? Does your new TC have a Clutch at all ? Some TC's do not have a clutch based on the stall and application of use....

[RANZTRANZ]

I see that you had issues with the electrical lockup of the TCC...you can eliminate the electrical lockup of the TCC by buying a Transgo 700LU Kit but you need the correct valve body...this is the best way to go when engaging and disengaging the TCC on the 700R4 when in a vehicle that was not designed for the 700 in my opinion... no need for the vac switch which creates a lock / unlock situations at city speeds.... this transgo kit eliminates all external electrical requirements because this kit will engage the TCC by hydraulic not electrical...

[RANZTRANZ]

I have provided a pic of the correct valve body you need, take a look at the pic and you see the dummy valves that come out of the VB...take a look at the one you have and see if you have this type of VB...I would highly suggest to go this route....the improper engage and disengage of the TCC can cause the problems that you showed in the pics of the burnt up 3/4 clutches and your 2/4 band... I have done hundreds of swaps to the 700's and this is the way to go...
Buy the 700 p transgo separator plate which works with most 700's...follow the instructions on the plate per the Transgo Shift kit along with using the VB gaskets to be used with the AUX valve body....

Just trying to help...Good luck