New filter and fresh fluid in, and the whine is gone. Sadly, reverse still slips. After a test drive, I've found that 3rd is also slipping. Previously, I thought it was having a hard time shifting into 3rd, but it's actually slipping once it gets there.

So, I'm looking at rebuilding the tranny over the next couple of months and would like to get a little advice.

First, any suggestions on where to get a good rebuild kit at a fair price would be appreciated.

Also, I don't want to spend money on a new torque converter if I don't need it. Is there a way to determine what shape mine is in?

Finally, since the pump was whining for a while, is there a probability that it's been damaged? Anything I should look for while it's apart?

On the bright side, I installed a drain plug in the pan while I had it off. That should make round two a little less messy.

Thanks in advance (again).

 

Jegs and Summit Racing have good kits at fair prices but even your local auto parts store....Auto Zone, NAPA, etc....should be able to get one for you. Lots of online vendors as well.





An age-old quandary.

First I'll say that I'm not an authority on the finer points of transmission overhaul.

I'm not aware of a DIY method of verifying that a converter is good.

When you do your teardown you'll be draining the convertor. Drain it into a clean container. If the fluid has metallic content I would not use the converter.

If the fluid is clean you *might* wanna use the convertor. It *might* be OK. Or it might not. Worth the risk? In my book, no, it isn't.

Next quandary....

IF you decide to replace the convertor and IF you ever intend on running your V12 to the 6000-6500 RPM that it is easily capable of, you won't want an off-the-shelf $129.95 rebuilt torque converter. You'll want something built for high RPM use and the correct stall speed (2100 rpm as I recall) for the Jag V12. This means extra expense.

Lots of choices. I had TCI Transmissions make one up for me. It was about $500. You can probably get a good one for less than that but, still, it won't be cheap.



The pump can be visually inspected/measured for wear/damage when the trans is apart.

Others with more trans overhaul expertise will chime in

Cheers
DD

 

If the Trans is slipping there will be debris in the oil you MUST replace the torque converter. If you don't you will be rebuilding the trans again.

 

Not what I wanted to hear, but better safe than sorry. I've got a complete rebuild kit and a new converter ordered. I'll also pick up new U-joints while I'm at it. Hopefully I'll dive in and get the transmission yanked out this weekend. Thanks for all the input.

 

Can you take a pic of the sludge in the pan?
Is it magnetic?
No parts or bronze/brass ring materials?
FYI, I found parts of my governor in the pan when I lost it.

 

I've already cleaned the pan and replaced the fluid, so no pictures. The sludge looked like grey mud and seemed to be at least partially magnetic. I didn't find any chunks, broken parts or even filings.

 

The sludge is particles of worn clutches and metal debris. Have you had it re built yet? Might be worth thinking about a mild shift kit to firm up the shifts slightly.

 

That's what I suspected about the sludge. I suppose metal debris in the bearings is what makes converter replacement mandatory?

I'll be rebuilding the transmission myself. I've started the removal process, but I have a lot of kid's activities to attend this weekend. Exhaust and driveshaft are off, but it's slow going with only an hour or two here and there to work on it. I expect this to take me 2-4 weeks to complete, but I'm not in a big hurry so no worries.

I've been thinking about the shift kit, but I'm on the fence. I'll keep it in mind, but I'm not convinced I'll get the bang for the buck I need to justify.

While I had the exhaust off, I had to start it to see what it sounds like. Not what I expected at all. More like a Japanese tuner car than the V8s I'm used to.

 

I've uncovered my transmission's problem. The wave steel in my direct clutch was broken and destroyed the rest of the clutch disks. The frictions and some of the steels have deformed to a bowl shape (heat distortion?). Some of the frictions have the fiber completely gone from one side, while the other side looks ok. Others have only part of the fiber eaten away.

I also found that the large lip seal on the direct piston was damaged. I'm not sure if the broken steel damaged the seal or if the bad seal caused the clutches to crater. Doesn't matter at this point.

The intermediate clutch and both bands look good, but I'll be replacing them since new ones came with the overhaul kit. I haven't gotten to the forward clutch yet, but I'll let you know what I find.

 

She will be good as good as new soon.

 

Maxlife ATF and a bottle of Lubegard Red. Running this in my XJS and it really made it run smooth. Lubegard Red has been used for years by many guys over at the "bobs is the oil guy website" forum and works great in many transmissions including any GM TH-400's... Helps clean up and loosen valves. Also the tranny will run cooler.

 

I found more broken parts. Mine had the plastic forward accumulator piston, and the center was busted out of it. I got a new aluminum one and installed it yesterday. The transmission is all buttoned up and ready to put back in. Hopefully I'll be back on the road this weekend.

 

I got the transmission back in and buttoned up over the weekend and took it for a test run. It runs and shifts perfectly (pats himself on the back)! I'm thrilled since this was my first transmission rebuild, and there was no guarantee it was going to work out. I really didn't want to tear into it, but I'm glad I did. It was a fun and interesting project and I learned a lot.

Now on to the next issue; new steering rack (sigh). It never ends.

 

Good work !


Cheers
DD

 

It's always satisfying when a project comes together.

I decided to take my car off the road and fix everything in one hit. Nearly finished now 18 months later.

 

I thought I had this one solved, but an issue has crept back in. When I took the car for its initial test drive, everything seemed to operate perfectly. But now that I've driven it a few times, it has a whine from the transimssion when I start it cold. The whine goes away after about a mile of driving and never comes back until the car sits over night or long enough to cool off completely. It shifts and drives like it should, warm or cold.

Fluid level is correct, and my pump clearances checked out when I had it apart. I suspect the rebuilt converter I installed. Any thoughts? I've only put 50-60 miles on it since the rebuild. Should I continue to run it and hope it clears up? That seems dangerous, but I dread the thought of pulling the transmission out again.

 

"Whine when cold" has been a 400 bugaboo since, well, since 1964!

In most cases it's fluid cavitation caused by a filter/pick-up problem. The fluid is a bit thicker when cold which exacerbates the problem. Going from memory I recall that some paper filters were a problem and a brass/metal mesh filter was usually recommended.

OR..... the filter seal-to-pipe connection isn't tight enough

Yes, a pump or convertor can whine as well....but let's hope it's the more common fluid cavitation issue


Cheers
DD

 

I know the new filter I put in is the fiber/paper type. I think I'll replace it with the brass screen type, but it may be a while before I get around to it. Is it dangerous to run it as is until I can switch them out?

 

Not sure.

I wouldn't be comfortable running it, personally. If it *is* a fluid cavitation problem then it seems to me that there's a risk of damage from lack of lubrication.

Other will chime in.

Cheers
DD

 

I have a brass screen type filter on order. I wasn't able to find one at a local auto parts store. Should be here early next week.

Is there anything besides the pick-up tube and o-rings I should be checking while I have the pan off (again). Thanks.