1990 TC Overdrive problems

[MarkzPartz]

I've got a 1990 TC signature series and the tranny works fine up to OD. Once in OD its constantly slipping. Anyone have suggestions? Does it need to be replaced or could it just be a plugged filter or some kind of electronic module? Are these AOD trannies or E4OD's? And what other cars use the same tranny?
Thanks

 

[LuxurySportCoupe]

I believe that is the aod tranny, same as a mark vii/cougar. Your od band is slipping, it will need to be replaced. You can start by changing the filter, but most likely you have lost overdrive for good and that band and/or trans will need replaced.

Same thing happened to me in the mark vii, so i just put a five speed in it.

Your gonna be driving around in d until you get it fixed, wont hurt anything but gas mileage.

 

[MarkzPartz]

Thanks for the info. Ive got an 84 Grand Marquis with OD I could use for parts. Does it have the same tranny as the 1990 TC? Ive rebuilt engines before, so how difficult would it be to rebuild the TC tranny or is it just better to replace it?

 

[thamarkman]

I think you could use the 84' tranny with minor modifications to the tv linkage.

 

[Sixlitre]

Two tips I'll give you for the transmission, whether it's to try and salvage this one (after you change the internal filter and ATF, like Luxury suggests) or safegaurd the next one; First get a huge cooler and install it ahead of the rad;

http://www.supermotors.org/vehicle....content

Next, and equally important, get a remote transmission filter;

http://www.supermotors.org/vehicle....content

These units are $30.00 and they are the cheapest insurance I've ever run across for transmissions. They clean absolutely EVERYTHING out of your fluid.

What's more you can spin the $3.00 filter off 6 times a year and prime the new one and replace it YOURSELF, costing you jack !

What does this do you ask ? When I bought my TC I had the typical 3rd to OD clunk. Drove it home, slapped the remote filter on, within a day's driving clunk gone !

This is not a replacement for changing your internal trans filter, it's an addition. After a years driving with the remote filter on my Bronco (my other AOD equipped vehicle), the fluid was clean and red when I dropped it, and the filter was pristine.

Does this actually work you ask ? My Bronco's AOD had death rattles and signs of it expiring at 160,000 miles. I was sure I'd need a trnas rebuild. Slapped this on, things improved to "like new" shifting (and I beat the whee out of it). That was over 100,000 miles ago !

My best advice for you

Sixlitre