The dreaded fluid change failure

[oharris]

My 97 Mountaineer (5.0, 4R70W AWD) started puking fluid out of the front of it. I pulled the tranny and replaced the torque converter/pump seal. I debated long and hard about replacing the rest of the fluid. After reading several threads on here on the subject including one guy who had problems after replacing just 2 quarts I decided to just go ahead and replace it all. I drained the torque converter, dropped the pan and replaced the filter. I put everything back together and took it for a short test drive last night. Everything seemed to work normally.
Today I drove it to work. After about 3 miles I noticed that during a down shift it seemed to just go into neutral. 6 miles later, I stopped at a stop sign and it would no longer move at all (except in reverse.) It’s as though it’s in neutral, the engine just revs although it does creep a bit.
What could be wrong? Is it a valve body problem or something else that I could just drop the pan and fix?

Thanks in advance.

 

[IAmTodd]

Have you checked the fluid level since filling it up?

 

[oharris]

Have you checked the fluid level since filling it up?

Yes, that was the first thing I checked when it stopped. It was fine.

 

[JK080]

My thought is that when is leaked out the front the fluid level dropped due to the leak and the low fluid condition caused the forward clutches to slip and burn. The new fluid came in and caused what was left on the clutches to come off and now it has lost forward. The forward clutches would have failed anyway if the fluid was not completely changed, the new fluid just accelerated it.

When we have a vehicle come into our shop and its been leaking and we have to pull it out to fix we like to do a reseal based on a inspection of the transmission, in most cases the forward and or the overdrive clutches will show signs of slipping or damaged to a point where they should not be used.

 

[alohamonte]

there's a shift linkage stem (probably not the technical term) that connects to a valve rod (probably no the technical term) inside the trans. you can see it when you drop the pan. could be a result of reinstalling the transmission. if it's not lined up perfectly, you can loose all gears and effectively be stuck park/neutral. does the shifter feel like it has the normal pressure and will hit every gear? or does it bind up?

 

[oharris]

My thought is that when is leaked out the front the fluid level dropped due to the leak and the low fluid condition caused the forward clutches to slip and burn. The new fluid came in and caused what was left on the clutches to come off and now it has lost forward. The forward clutches would have failed anyway if the fluid was not completely changed, the new fluid just accelerated it.

When we have a vehicle come into our shop and its been leaking and we have to pull it out to fix we like to do a reseal based on a inspection of the transmission, in most cases the forward and or the overdrive clutches will show signs of slipping or damaged to a point where they should not be used.

That is what I'm beginning to think. The only thing that puzzles me is it happened so suddenly. It was working normally then suddenly it wasn't. Does a clutch really go out that fast? There no signs of slipping at all prior.

 

[oharris]

there's a shift linkage stem (probably not the technical term) that connects to a valve rod (probably no the technical term) inside the trans. you can see it when you drop the pan. could be a result of reinstalling the transmission. if it's not lined up perfectly, you can loose all gears and effectively be stuck park/neutral. does the shifter feel like it has the normal pressure and will hit every gear? or does it bind up?

The shifter feels perfectly normal. Every detent is easily felt. It's definitely going into park, reverse and other than reverse. Would it do that if the rod had shifted?