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700-R4 no 3-4 please help.

983 views 4 replies 4 participants last post by  DarkKnight33 
#1 ·
OK guys, I have used the search button and read what was there regarding the no 3-4 gear issue. However, I still have some unanswered questions so please bear with me, I will try to be as specific as possible.

I have an '88 T/A GTA 143,000 & about 3,000-4,000 on a 1 yr. old rebuilt tranny. The last trans went when the torque converter grenaded in traffic. (I wasn't driving it at the time, so I don't know) I had a local shop install a rebuilt unit. About 3-4 months after they installed the unit, I lost 3rd and 4th while driving ormally. Since it was under warranty, I had them fix it, no problem. Now it's 2 months out of warranty and again while getting onto Rt. 50 everything was normal, shifter was in OD, trans was in first, then second, then third, wait no something's wrong the enigne is revving like crazy, WTH? When the shifter is in OD, I have first and second fine, slips (very badly) in third and no fourth. I can shift it manually into first and second just fine as well, but slips in manual third and no fourth. I understand that the 3-4 clutches are probably toast. I wasn't dogging the car though, and it's happened twice, so what keeps causing 3-4 to go? And more importantly how can I prevent it from happening again? I intend to rebuild it myself this time, and I have read that packing the clutches with a tighter clearance can help. Anything you guys can clue me in on for the rebuild would be nice as well. Thanks in advance.
 
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#3 ·
Gone & gone again

Hey. Sounds like you enjoy fixing these things. But what is causing all of the problems? Why do they keep going out? A very good source of knowledge is the local junk yard. Very few cars are there because of faulty trans. You may have a flex plate problem, shaft alignment, etc. Check with a local about the specifics of your car. They know a lot of common problems.

Good luck.

hr41pearl
 
#4 ·
MAny things cause the 3/4 pack to wear out .

The shop could be over looking a loose input shaft into the aluminum drum.

Bad sealing ring surface in the stator support.

Worn out boost valves, weak PR spring.

bad TV cable adjustment.... it is adjusted correctly??

It appears they are not correcting the problem with the 3/4 frictions.
 
#5 ·
The transmission they installed after the second failure was another rebuilt unit. They didn't bother to repair the unit they installed. I pressed the mechanic for information on what happaned, but he claimed not to remember. How could the TV cable have caused the failure? It's fairly simple to adjust, push it in, floor the pedal or open the throttle manually, and it's done. I checked the adjustment, it was fine.
 
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