I have a 90 cougar 3.8w/overdrive. AOD trans.
I just had the trans seals, filter and engine seal changed cause of smoke when driving on the highway. After leaving the shop, I checked my fluid level and it was perfect. After local driving for a few days, i get on the highway, speed up to kick in the overdrive and she flies like a bird. All gears and all ranges are better than before since changing the fluid and filter.
After about 2 minutes of driving in OD at about 75 to 80 mph, here comes that damn smoke again! I thought maybe it was residual fluid still on the exhast from the previous leak but it just got worse after about ten minutes. I check the trans fluid and its all the way up the stick.

What could this be????

 

Maybe there is a plugged vent causing too much pressure in the case? Don't know about this tranny so can't say for sure.

If the fluid is all the way up the stick, it is also dribbling out of the tube? If it dribbles out of the tube, that would cause smoke.

Are all the seals for the case in good condition? You should be able to see any leakage, assuming the shop cleaned up the case when they worked on it. Where is the fluid coming from is the question you need answered. Is the fluid stil red and smells nice and chemically, not smokey?

Good Luck,

Jim Henderson

I would definitely take it back to the shop and tell them what happened.

 

Thanks again Jim.

I took my car back today and they found no leakage in the trans, they did find leakage in my valve cover gasket and replaced it for free. Trans fluid looks a little dirty but not black. So here I go and hit I-95 and go into overdrive. I was good for about five minutes and here comes the smoke again, so i ran it for like 20 minutes and brought it back to the shop smoking. they cleaned up all possible points of leakage to see where the fluid was comming from and nothing is leaking. Checking the fluid level again, its all the way up the stick. the head mechanic determined that the trans fluid is not circulating correctly and is overflowing from the dipstick. He also said this is a sign of a bad transmission, but being that the trans shifts fine, to run it local for a few days and keep an eye on it before we jump into replacing the trans.
lol,
I am stumped!
Any thoughts on this mystery???

 

"The trans fluid was a little dirty"!?

When they replaced the seals did they replace the fluid? I would assume so but who knows? If they did replace the fluid, and it is "dirty" already, you do have a problem. I would guess the tranny will be ready for a rebuild, if your fluid got dirty in just a few days. That or they didn't do a thorough job of cleaning things out. Hmmm.

It is possible that some of the passages are clogged or the pump is not working well. There is also a possibility that the tranny cooler is clogged which may be causing the overheating. Many shop manuals recommend periodic cleanouts of the coolers. I never realized they needed this until just a year ago while reading a shop manual.

I would say if the tranny is smoking and the fluid is being forced up the tube, then there is a problem and eventually the tranny will fail.

Who is going to pay if things blow up? At worst I would expect what you already paid to be credited towards a rebuild(if required). For example, I think you already paid $400. If they determine the tranny does need a rebuild, I would guestimate the cost to be about $1,300, minus $400 for $900 net.

Once again, let me remind you I am no expert. I am a good hobby mechanic and I read a lot and have had the privilege of paying experts several times for the error of my ways. Hopefully the shop you are using is expert and will stand by their previous work.

Good Luck,

Jim Henderson