Hello everyone !

Just rebuild my 700r4 after 3-4 clutch pack burnt due to excessive clearance.

First day, all seems to work. Good rpm shifting, not smooth, not hard. Just removed 3/4 liter at the end of the test to have a good level.
At the same time, service engine soon was lightening because speed display was off...

Second day, shifting was late and harder. About 2800 rpm to shift at low charge.
Tried to re-check tv cable (i know how to). Just moved 1 or 2mm maybe. Added a little oil in tranny.
Then shifting is really smooooosmoooooth, so i don't really know when each gear is on.
re-checked my oil level. No changes.
I think 4th goes on at high speed, but TCC doesn't work any more, due to VSS ?

TV cable seems to be ok, when pulling it too.
I don't understand shifting problems. It's like converter slipping too much. But gears seems to be engaged.

Any ideas ?
Thanks

 

Your first task is to set the TV cable as the manual tells you and then leave it there. Not 1 or 2 mm but where it tells you to. You say you have the ATSG manual. Put a pressure gauge on and test the pressures as indicated in the charts. My guess is that the TV valve is sticking. There should have been a small spiral spring in your rebuild kit that is to be installed on the end of the valve. Did you disassemble the valve body and clean it? With all the burnt clutch material floating around in the oil, there may be other sticking valves. Did you flush the cooling lines? Also, there could be an issue with the governor. Make sure the gear is not broken or apple-cored.

 

To set the tv cable you have to have the tension tight at full throttle, that's it no other situations. go under hood and put butterflies open and push the button on tv cable but then pull/push the middle part out or in to adjust, it will not self adjust like the manual says.
Make sure at full throttle it is tight, it can be adjusted a little either way. I adjusted mine after rebuild and it is perfect now. BUT you have to pull the "adjuster by hand" just because of age ect. Good Luck

 

^^^^^ That's like describing to ten different people how long a piece of string is. Widely varying results. I have a multitude of technical books and I can not find one that states it is OK to adjust it "a little each way". However, they all state that the TV valve must start building pressure immediately upon the engine RPM increase. Vary from the proper procedure and you burn clutches. Simple. I will stand corrected if you can post an excerpt from a reliable, recognized technical publication saying otherwise(not an article in a car magazine written by a freelancer whose forte is chic food recipes)

 

I just adjusted it too tight the first time and my neck jerked when it shifted 1 to 2nd. I relaxed it a little and now it is just right for me. If it is too loose it shifts later and may slip 1st to second is 18 mph IIRC.
It cannot be broken or hanging loose that is not what I meant. I adjusted it only 1 to 2 mm that's all there is. But it made a difference.Good Luck

 

Thanks guys !
Last time I checked TV cable, at WOT, tv plunger was full pushed (saw when oil pan removed).
Not easy to check pressures lines now. I'll try. Do you know which thread size it is (to connect gauge) ?
I checked valve body. Everything was unsticked and/or disassembled. BUT I don't remember disassembled TV valve... I thought everything was ok by moving plunger... That's my fault... I saw the spring and not put it...
I ordered and Transgo kit to fix it. Hope that will be ok
Thanks again

 

And for TCC, I only have to resolve VSS information (gear, connections, VSS, gauge connection...).
Wait and see

 

The TV valve has balance oil fed to it on the end through an orifice. If the valve bore is worn and leaks more oil than the orifice can supply, then the TV valve may not move back toward the plunger. The helical spring corrects this. There is a roll pin that holds the TV valve in place. Hopefully it hasn't been pushed in too far or you are going to learn some new words.

 

When removing VB, I presume that the roll pin will be accessible ?
I have other VB gaskets.

I read that oftenly, if TV sitcks, shifting is hard and late (one time it did that). Otherwise can it be soft or blurry (everytime now) ?
Thank you all

 

Soft shifts can be caused by many things but usually from something leaking. A sticking "open" TV valve would be extremely unlikely. The valve is actually quite small and the apply spring fairly robust. A rolled or torn lip seal is common. Did you air check your drums before assembly? I think it is important now that you do the pressure tests. Make sure you use the correct gaskets. Most rebuild kits I have used have two sets. They are not the same.

 

Hello !
Yes, checked with air pressure before closing the trans. All seem to be ok !
Only first test was good while running with tranny in car. 2nd day : adjusted level, speedo was out of order (gear retainer clip broke..) and all seem to slip too much...

Bought Transgo kit (tv, springs...).
Before install it, I removed oil pan, I sucked up the oil for more easiness. Level was good (while engine running) before sucking, but I've only 3 quarts aspirated... (when removed pan, it was empty of course). 3 quarts is really low I think !
When I drained tranny the first time (when I bought the car with no 3rd and 4th), I didn't sucked oil, I remember level was max, and it overflowed pan when removing it. So I presume more than 3 quarts !!
Don't understand.

So I filled 5 quarts before running this time.
After few miles, engine/trans hot at idle, level is very above max level... (maybe between 1/2 and 3/4" above).
Any explication ? If the level is good now, there is lower quantity than theory... (maybe 2 or 3 quarts less). Dipstik seems to be original...

NB : Transgo has corrected my problem at low charge, shift is better. At high charge, not really tested, but I could be better. No found 4th too... Waiting for my new clips to reinstall speedo gear and hope converter clutch will make a difference.

I wish I have a great tranny...

Thanks !

 

I don't know what is available to you but you may have reached the point where it needs to go to a trans shop that does this work on a daily basis. As I said before, testing and documentation of the pressures as outlined in the test chart is crutial now to try and pinpoint your problem. Anything I could suggest now would simply be a "maybe try this" and that is not proper diagnosis. Buy me a ticket to France and I will help you try and sort this out.

EDIT: I asked you this question before but you did not answer it. Did you flush the cooler lines when you had the trans out? With the car just going a few easy miles, there is no reason for the trans to get hot. You need to check to make sure the oil is circulating. Remove the top cooler line at the transmission and attach a hose to it placed in a bucket. Run the car momentarily and check to see that you have good flow. Also, did you have the pump apart to clean/rebuild? You may be low on pressure output. Once again, you need to check the pressures.

 

I'm a little afraid about this tranny, I deduce I'm the 3rd person I open it... why ?
I've several problems on it now (3rd to 2nd manually is like neutral, only change down at only low rpm)...
I've only a 8 bar gauge. Tested at 1000rpm with TV, pressure is in high tolerance. Without TV connected at 1000 rpm, pressure increase proportionaly really good when pulling TV cable (I presume proportionaly in tolerance at full).
Cleaned and reset oil pump before, checked and all was good.
No cleaned lines

A friend of me knows somebody in California. If I don't manage to resolve it quickly, I'll try to order a new 700r4. Don't want to remove several times the tranny...
Thanks Arbee !! And I prefer buy a new tranny instead a ticket to plane lol But you are welcome in France and of course at home when you want

 

Not to highjack the thread, trans works is over my head. But I did learn a lot reading here. I have a question. 93 lt1 700r4 50K miles mostly early on years 0-6. shifting 1 to 2 works well under both commuter and wot acceleration. 2 to 3 is hard/firm. 3 to OD is pretty normal but I haven't pushed it wot to 200 mph but it seems "normal" enough. fluids have been changed. Is there a cable tuning step that matters for 2 to 3 only? sorry if its a simpleton question. How hard is it to do the valve kit tune up job for a reasonably clever weekend warrior? can that be done in the car? Thanks for looking.

 

 

Adjusting the TV cable is common to all pressures and gear changes. There may be individual shift valve kits but that is not something I have felt a need to keep up on. The 2nd gear apply piston is the accumulator for third gear. There may be leaking seals that are causing the harsh 2-3. I do not know what you are referring to when you say "Valve kit tune up".

 

Hello !
Do you want news ?
Fixed speedo gear with a new retainer clips. Speed displays Lock-up works. Trans is really different now. BUT...

- when D is selected, D runs with quickly lock-up at 42mph (it locks at stabilized speed or locks during accelerating too...), and then OD shifts with lockup too... instead D is always selected... Before transgo kit, I don't remember if there was this issue or not. Anyway, lock-up is too often activated and too quick over 42mph... in D and OD. Impossible to drive durably over 42mph without lock-up.
- manually 3-2 shift goes to neutral at mid or high rpm. When rmp is going to low, 2nd finally shift.

I presume shifts were quick at first test, but I think it's TCC which gave this impression.
I can make you videos, maybe it will be more explained to understand how tranny works.
Maybe converter seems to slip when shifting due to long ratio rear axle (2,59) ?

 

What year Vette. 1993 with ASR is done using service manual. Very specific as you have to use a torque wrench within the mechanics of the ASR unit.
92 and older, there is a method and one where you can take the pan off and actually measure the TV cable during WOT..
But seriously, you want to burn up a 700R4/4l60, then dont set it properly and do it by seat of the pants.. The Service manual has pressures too to check, and every year is a bit different using ATSG manuals too..
Good luck.

 

My 700 r4 also goes into lockup at 42 mph. It is supposed to do that in 2=3=OD. It is to cool transmission more and save gas. Now under full throttle you should not feel it bacause when you floor it
the TPS will signal high voltage and lock up instant. That is for fast starting off the line. My 3=2 shift also does not drop down instantly goes to a neutral feel then slowly gets to 2nd. I believe that is to protect from wheel lock at high speed. I remember my buddy in high school crashed his 69 Mustang on the Valley curves we asked him what happened he said he dropped it down to 2nd. Food for thought sounds like it is working fine.

 

^^^^^ This is interesting. Can you expand a bit more on your thoughts and tell us the source of this information?