4T60-E Transmission Issues
 

I have a 1994 Bonneville SLE with only 77,000 milles and the 4t60-E transmission. That is not a typo. It was my grandmothers car. The car stoped going to 4th gear (overdrive). It shifts and drives great in the first three gears though. I have driving it this way for a month now and the fluid is not burning. There is a modulator and I have been told there are selenoids that control two gears each. Does anyone have any idea what the problem could be?

Thanks! :?:

mine had this problem, but only intermittently.

thread here

http://www.bonnevilleclub.com/forum/...ht=lost++today

Please start by telling us what your fluid looks like after a short drive:

1. Smell
2. Color (describe it well)
3. Taste (kidding)
4. Level on the dipstick at idle

I've looked into this a little bit. There's a round plug that connects to your transmission. You can find it under the throttle body. Check that all the wires are there. There's one at the top of mine that was broken on my 94. That wire controls (to an extent) Shift Solenoid B. Even after fixing the break in the wire, I still haven't gotten SSB to work right.

Troubleshooting:

Shut off your car on an open road that permits hitting 4th gear. Use the gas pedal to go up to about 30, and then use cruise control to continue accelerating to around 55mph. Are you in 4th? If so, hit the gas. That's exactly when you'll drop down to 3rd gear. No matter what you do from then on, never again will you go to 4th gear until you shut off your car, start it again, and use cruise control to get up there.

This is a recurring problem with 4T60E transmissions that I've seen here, but no one can ever get to the bottom of it as far as I know. The code that I get is "Failed TCC." I don't remember quite what that is, but it's not Torque Converter Clutch. Do you have any codes?

EDIT: I found these pictures through willwren's signature link:
http://www.williamwren.com/Bonnevill..._connector.jpg
http://www.williamwren.com/Bonnevill...humba/img9.htm
http://www.williamwren.com/Bonnevill...umba/img10.htm
http://www.williamwren.com/Bonnevill...umba/img11.htm
http://www.williamwren.com/Bonnevill...umba/img12.htm

Yeh, there is also a "TCC Brake Input Circuit" code that can keep it from shifting into OD. On a 93, it is code 38, but don't know on a 94. It registers a code but does not turn on the SES light. It is looking for 12 v, via fuse 16 and half of the brake switch and branches to the PCM and also one side of the solenoid. The other side of the solenoid gets the drive from the PCM. So, if you can get your codes read, it may tell you something on this.

was just wondering if anybody firgured out a fix for this problem my 94 ssei does the excact thing, no overdrive unless i use the cruise control, but at 75 it still runs about 300 rpms higher than my 94 or 95 se...almost like torque converter isnt locking up...

i had the same problem with mine, banged my head for awhile until i decided to rebuild it. These have a common problem with the tcc solenoid valve releasing when it gets hot or not engaging at all. apparently it has something to do with the valve wearing out and not sealing properly. The guys who rebuilt my tranny got a kit from sonnax that made to fix this problem with an oversize valve

here's the homework the owner gave me at the time to read up on.

http://www.sonnax.com/instructions/SC-4T60-E-93-IN.pdf

basically they bore it out and install an over-sized valve and all is good again.

also, when they had it all apart i got them to replace the differential with one from a ssei(apparently the se and ssei tranny's carry similar parts), which is beefier and changed the final drive, so now i do just under 2,500 rpm at 120 km/h.

did you have your transmission completly rebuilt? the trans in my car looks to be a jasper replacement, any idea what it would cost to to put in the kit your talking about? naturally i was hoping for an easy fix, or at least something i could maybe tackle thanks

I had the tranny rebuilt completely. the kit was around $300 canadian. as for tackling this your self... i wouldn't recommend it. I'd say its pretty hard to do unless u have experience with rebuilding transmission.