TC noise and overheating under power-'91 700r4

[overS-10ded]

This morning pulling out of the drive way I put my '91 700r4 in reverse and the TC sounded noticable upon shifting into reverse. Drive sounded normal (no sound!) then reverse sounded normal. Then later today the temp started climbing like crazy, especially when accelerating then would cool quickly while coasting or crusing. But accelerating even lightly would increase the temp rapidly on my digital trans temp, up to 240 at one time, but then came right down to 210 coasting or crusing which is still about 40 degrees from normal. on the interstate onramp, up to 225 but down to normal 155 at cruise. Is the TC going out? There are no other symptoms except an occasional TC noise....clicking kinda...and the temp at this time. Trying to avoid the TC failing and trashing a good trans if that is the case. Thanks for any info!

Bruce

 

[Loeryder]

Re: TC noise and overheating under power-'91 700r4

I am no trans expert but I have broken 3 700s now...

The TC can generate heat in a hurry if it is not locking up properly.
Can you feel it locking up cruising in OD or can you lock it manually via the ALDL?
Check the connector on the drivers side of the trans case and make sure its seated.
If thats not plugged in the ECM cannot command lockup.


I wouldn't beat on it at all while its seeing those temps or the clutches will be burned if they aren't already.

My next step would be to drop the pan and cut open the filter.
The last one I cut open had "fish scales" in the pan and through the filter.
Still shifted hard 1-2 and pulled in 3rd gear but reverse was choppy and there was a vibration under heavy acceleration.

 

[overS-10ded]

Re: TC noise and overheating under power-'91 700r4

I've been through my share of these 700's too. This is a JET one that supposedly in 2000 was a good trans. They don't make trannys anymore! This one is alright but I don't want to trash it if I can catch the TC going before it takes everything out with it as they seem to do. Luckily I have the temp gauge or else I wouldn't have noticed. The sound is normal again. It is locking up in OD too as normal. The temps come down fast and to normal once it locked up at interstate cruise. Once I pulled off the interstate and the trans unlocked though the temps started rising fast again. I sat in my drive way with it in gear idling and it fluctuated between 210-220. Still 40 degrees hotter than usual. No unusual shudder (like the lockup clutch going) and no vibration other then a CV joint I'm needing to R&R. Reverse felt fine, just the clicking noise like the TC was hitting/rubbing lightly on something. But no noise now. Thanks for the info!

Bruce

 

[4C FED]

Re: TC noise and overheating under power-'91 700r4

That clicking noise was the same noise mine made as well when it was warmed up.
I tore trans down & found nothing wrong. Installed new TC & noise went away.

 

[overS-10ded]

Re: TC noise and overheating under power-'91 700r4

So what is "the noise"?

 

[4C FED]

Re: TC noise and overheating under power-'91 700r4

Couldn't say. I didn't have the TC cut open. Wasn't worth the time & effort. I just left it with the tranny guy so he could use it for a core.