Hi Guys,

I'm new to this board, but an old salt on a few BMW forums. I searched extensively for existing threads about the issue I'm trying to flesh out, but came up dry so I figured I would ask those of you who have hands-on experience with this chassis for help

Here's the background; about six months ago my father-in-law bought himself an automatic '89 XJ6 in fantastic cosmetic condition as a fun DD. Aside from a few electrical quirks (sensor reporting), slight seepage from the valve cover gasket, and a bum fuel pump it's been been reliable and he's enjoyed his short ownership.

Apparently a few weeks ago, he was out running errands when suddenly the car began to hemorrhage transmission fluid. He was near a service station, and determined [on his own] that with a few quarts of fresh fluid he could limp it home...I probably would have called a flatbed to tow the car home, but that's beyond the scope of this question. He lives in Maine, but my wife and I live in Boston so I wasn't able to drive up take a look at the car for about a week. When I finally had an opportunity to get the car up on jack stands I was pretty surprised to witness the severity of the leak. Basically when the car is started, fluid begins to immediate pour out of the 'vent' at the bottom of the bellhousing/torque converter. The leak stops when the engine is turned off. The high flow rate coupled with the fact that it only leaks while the engine is running is pretty indicative that whatever let go is allowing fluid to escape only when the system is pressurized.

Here is where I need help, I have done a lot of transmission work on manual BMW's, but have only limited experience with automatics. From the research I've done I believe the car is equipped with a ZF HP22 tranny. My first thought is that it's simply the input shaft seal that let go, and the fix will require disconnecting the kickdown cable, dropping the transmission, pulling the old seal and replacing with new, and then buttoning the whole system back up again. What I'd like to know is: Is the input shaft seal a common failure point? Does the description of the leak make you immediately think something else is the culprit? Are any special tools required (torx sockets, micrometer, etc)? Any tips, tricks, or warnings that I should be aware of that are typical of Jaguars?

Any help that you can offer is appreciated and I will be checking this thread often. I can answer any questions that you might have that would help to narrow down the problem so, please ask away. Thanks a lot, I look forward to becoming a part of this community!

 

As you have correctly surmised, there is a seal on the inlet shaft, and it has a torque converter rotating on it, which is supplied with fluid from the box, in fact it is pumped continuously in and out. So it looks as if the seals have gone in a big way, unless there is a crack in the torque converter body itself.

All you can do is to extract the transmission and bell housing, dismantle and inspect to determine the exact fault. There may be special tools needed if it is a ZF box. I replaced the input shaft seal on a Borg Warner 66, but that was on a 1980 XJ6

 

Hi Mitchell, thanks a lot for your reply. I've done some further poking around and indeed it appears that the culprit is either the input shaft seal, or as you mentioned the TC body itself. The plan is to begin working on the car tomorrow morning, hopefully have the transmission out by midday, and then plug/chug as necessary. I have my fingers crossed that the issue is just the seal, as I have that part on hand. If the TC itself needs to be replaced due to a crack or compromised bushing it will have to be ordered and I'll need to make another trip to finish the job.

As far as disconnecting/reconnecting the kickdown cable goes (and I'm not sure if that feature was present on the BW box) is the main difficulty simply taking careful measurements at the start in order to line it up properly on the reinstallation?

-Nick

 

Can I suggest use of a digital camera to photograph things before anything is stripped. This way you can see how things lie as per before the strip down.

Normally for kick-down cables, there is a setting in the manual document somewhere; there was for my BW 66. Kick-down cable is the most misnamed part on the planet, as it governs how the box changes at all speeds and throttle settings in conjunction with an internal governor because it provides an indication of driver demand for performance, linked as it is to throttle demand.
However, electronics has taken over much of the old way things were done in auto gearboxes, so there may be no governor on a ZF box