When installing the transmission in the Xk8 after replacing the engine rear main seal the torque converter slipped out of position. I didn't know until I tried to put the screws back in and found that the torque converter was bound tight to the flywheel.

I dropped the transmission again, tipped it up, removed the torque converter and didn't see a problem, so I put it all together again and added 8 qts fluid through the transmission cooler return line.

I started the car, shifted to R and D, felt the engine bog down a little as it engaged, so I put it back in P and pulled the fill plug to adjust the level as it came to temp. But all the fluid came out, so I assume something is broken.

Is someone with knowledge of the inside of the transmission able to suggest what failed? I assume the torque converter would fill with fluid quickly without being in gear, and what came out the fill port looked like about 5 qts. at least.

 

Somethings not adding up- even if there were broken parts, it shouldn't drain all the oil out the fill hole unless it was overfilled ALTHOUGH the TC holds some, so maybe it hadn't filled yet?

Couple things come to mind:
Did the TC go fully "home" when you put it back? Is it a new one? If so it needs to fill up with fluid. (or be filled before installing, which I think is the correct thing to do)
Now that the fluid is out (or possibly just low) does it operate as it should?

 

When you reinstalled the converter did you rotate it until the pump drive engages? It sounds like the pump is not working.

The transmission you are installing is it the original or a new one?

 

It's the transmission I took out to work on the engine, Same for the torque converter. When I took the TC out after discovering that it was in wrong I lost a lot of fluid. Between that and what was originally drained from the transmission I estimated close to eight quarts, so that's what I refilled. I'm sure the TC was in correctly and I could feel the internal resistance when I rotated it.

After running the engine for about five minutes, shifting through D and R a couple of times I removed the fill plug, with the engine running and in P. Five qts. came out the fill hole, and with about three still in the pan that accounts for all of the eight quarts I added.

When I had the valve body out a couple of years ago I drained close to seven qts., and refilled the same way with no problem.

For some reason none of the fluid I put in was retained. Does the TC take a long time to refill? Should I refill again and let it run for a longer period, maybe in gear on the lift?

 

Since you don't know the actual amount of fluid in the trans, I would leave things connected up, and fill it as per the procedure. Let's not assume you were just full. You may have been overfull. Don't you just love these dipstickless transmissions? It's like having to be psychic to work on your car.....By the way, I did the same thing when installing my trans, only I ended up breaking off a hole in the bell housing...Best of luck......Mike

 

Thanks Mike. It's not overfilled because there was a low level code after I pulled the fill plug and all the fluid drained. I kept all the fluid originally drained before I pulled the tranny, so I know how much I started with.

When the bellhousing was fastened to the engine with the TC not seated, I wonder if I broke the pump. I assume the pump drive is just a splined plate, or is that wrong?

I put the fluid back in and started the engine. No unusual noise and when I put it in gear the engine slows a little as if the gear is engaged, but no movement at the back and I can rotate the rear wheels by hand with no sense of connection to the transmission even though it's in gear.

I'm going to stop messing with it just in case the pump is not working and I damage some bearings. Tomorrow I'll start taking everything apart again.

 

First I want to say I am no expert on the trans but it sounds like your torque converter is not connected to the trans to create a flow that makes the trans work and the fact that you are losing fluid near the amount you put in tells me it is not right. Sit back and rethink what has been done then go at it again tomorrow.

When you pulled the trans did you use a trans lift? If the trans did not come out freely it might have put undo pressure on the front spline causing part of your problem or the loss of a key set.

 

Everything came out easily. Looking at the end of the TC shaft it is notched for two opposing dogs down inside. These are very robust parts and it would be impossible to damage them, nor do they show signs of damage.

I'll just have to pull the transmission and tear it down, at least to the pump and A drum level. It's interesting that there is no transmission fault or stored codes. It will take a day or two to get the transmission out an supported upright so that I can tear ir down.

 

Another thought. One of my friends was tightening the bellhousing bolts and heard a ping or click from the bellhousing. He thought it was just the dowel pin seating.

But the flywheel was pressing against the torque converter because the shaft wasn't seated correctly, as mention in my first post. Could this have been something in the TC breaking? I just don't know enough about TC operation to make an educated guess.

 

Does not sound good.

Gus
www.jagrepair.com

 

No, it doesn't.
I need to know if the torque converter is self priming, or should I have filled it before reinstalling? I will PM motorcarman.
I think I will get the transmission part # today and ask if someone has a used torque converter they will sell me.

 

IF something broke, I would put my money on the pump internals, not the TC.

 

That's what I'm afraid of. If those dogs I see down inside where the shaft seats are part of the pump it sounds very likely.

 

Fortunately, the pump is still at the front of the transmission and "easy" to get to.

 

It was the pump that broke by not having the torque converter seated properly. I had checked to see that the TC was able to move before tightening the bellhousing, but it was jammed against the flywheel when the bolts were drawn up.
There was a click that should have been a warning to take the transmission back out and check. Fortunately another member offered to remove the pump and TC from a spare engine, so all I need are some gaskets, seals and o-rings and the car will be on the road again.

 

VERY NICE of that member to offer.

Keep us posted on the progress!

 

Is there a source that will sell the front seal, gasket for the housing and o-rings for the cooler lines, or will I have to buy a complete gasket set?

 

FYI
The torque converter oil seal is BMW part# 24 31 1 422 671. I found one on ebay for $14 w/ free shipping.

 

your on a slippery slope . the problem you now have is all the metal that has ground off the stator (back side of the pump) and has gone through the entire system , valve body ,electronics , cooler , convertor . you will now chase that metal till it's cleaned out .
if,when , valves hang up cause of the metal , it will cause failures . trans needs to be pulled ,cleaned , replace convertor (only way to get metal out) ,and flush the cooler.
good luck , I rebuild transmissions for a living , this is not unique to zf's , but any auto trans. same theory applies to a 1970 Camaro or mustang

 

The dogs snapped off clean and there was no indication of abrasion on any parts, but I'll look again today with magnification.

The pump did not function, so with no circulation I would not think any particulates would be spread through the system. But I understand your concern.