My 94 GTP, will engage in OD, and seem to run fine, but then the tranny drops into 3rd, and won't engage into OD again, until I shut the motor off, and re-start it. Then it will go into OD again, for a few miles, and do the same thing.
I had a trans shop, put in a new TCC switch, and A and B shift solenoids.
Any ideas????????????????

This is a known issue for the earlier 4T60E trans.

Automatic transmission: 4T60E transmissions may drop out of drive while cruising; shift erratically; or have no second, third, or fourth gear because of a bad ground connection for the shift solenoids. (1994)

This is a known issue for the earlier 4T60E trans.

Automatic transmission: 4T60E transmissions may drop out of drive while cruising; shift erratically; or have no second, third, or fourth gear because of a bad ground connection for the shift solenoids. (1994)

Thanks for the reply.
Were can the solenoids be grounded? Do you need to get inside the tranny to do it?
The trans shop just replaced the solenoids!!!!! I would hope they would of done it then.

Is this the transmission that is in the '95 Bonneville? The reason I ask is because I had this exact problem for about a year and never got it fixed, even after taking the car to many dealerships, transmission shops, and such. After about $1000 in random parts I gave up.

Red - When it shifts out of OD can you put the tranny in neutral and restart the engine? mine would do that and i'm just trying to figure out if the problems were the same.

Is this the transmission that is in the '95 Bonneville? The reason I ask is because I had this exact problem for about a year and never got it fixed, even after taking the car to many dealerships, transmission shops, and such. After about $1000 in random parts I gave up.

Red - When it shifts out of OD can you put the tranny in neutral and restart the engine? mine would do that and i'm just trying to figure out if the problems were the same.


Yes, I tried that last night.
This fixes the problem for a little while, but then the tranny will just drop into 3rd again, and the TC will not lock up.
The tranny shop can't figure out the problem, they want to rebuild the whole tranny, for $1300 of course.

I've got the same problem.

I've replaced the TCC solenoid, replaced the filter and oil, and it does exactly the same thing as described in the original post.

If I'm going over 40 mph and I ground the A solenoid, it will go into 4th gear and stay there. But when the TCC solenoid goes out, it doesn't come back.

Has anyone managed to actually resolve this issue? Is it possible to gerrymander to have 4th gear come in without the TCC being engaged?

Any help would be very much appreciated!

Nick

The car is going in for a new Torque Converter today. The tranny shop says the TC is slipping, ands causing the computer to dis-engage OD and TC lock up!
I will keep you posted, if this does fix the problem.