I have a 2000 XK8 with about 90K miles. For the past few months (I drive it rarely), it has a pretty hard (not quite violent) shift into R when cold, then a similar hard shift into 1st when coming out of that initial R (i.e., start the car, let idle settle down, shift into R, back out of garage, shift into D). After driving it for maybe 5 minutes, this behavior is gone, and it shifts back and forth from P-->R-->D smoothly.

The 2nd issue is more disconcerting, and doesn't seem to matter about engine/trans temp. Driving along on a highway for instance...exit onto a ramp...come to a stop or near-stop...depress gas pedal...transmission seems to not be in gear, hesitates, then shifts into 1st, sometimes kind of hard. This doesn't happen all the time, and if I hit the gas very gently, it never happens.

Filter was changes about 20K miles ago, fluid level checked recently and is correct (using correct procedure).

Thoughts?

 

What fluid was used?

 

Pentosin ATF-1

 

Sounds like a typical a drum problem common to the ZF 5HP24 transmission. A search of 'a drum' in this forum (X100) and the X308 forum will give you a good idea of what's involved.

 

My car did something similar and turned out to be the torque converter. Apparently, when they start failing the transmission oil pressure fails to build up sufficiently causing all sorts of transmission issues along with the familiar sounding bump on start. A used bit would set you back 100-200 on eBay. Was lucky to find one at 70+ shipping

 

Are you sure this isn't an tcm issue? My car does the same thing when it's cold outside. It will jerk into reverse but will go into drive smoothly once I back out of the driveway. I was told by other members it's normal for the car coming to a quick stop then getting back on the fast to jerk due to the TCM programming. My transmission shifts fine. I have almost 110k miles on it and I've changed the fluid many times. It only has these issues when it's cold outside as well when it's summer time or spring time the car goes into gear very smoothly and quickly. It doesn't hesitate in the cold just roughly goes into reverse. It goes into drive and reverse very quickly though.

 

Something in the ZF transmission is nearing failure. It could be the inevitable A drum, or it could be the torque converter.

Pull the codes and see what it says. Looking ahead, you may see the following scenario.

Mine would give me the "GEARBOX FAULT" warning intermittently which can be cleared by an engine restart. Ultimately "GEARBOX FAULT" becomes permanent and I'm left with only Reverse and Fifth gear when the A drum fails completely.

Be mentally prepared to face the A drum replacement in the future. It may be wise to then have the entire transmission rebuilt.

 

Well, alas, it's the A drum. About $3,500 to rebuild. Sigh...

Thanks to folks on this thread.

 

Is that price for a complete rebuild or for just A drum repair?

 

Rebuild. I should have a complete cost breakdown by Monday and will post an update.

 

Who is doing the job? I am in northwest Raleigh and know several shops that are very familiar with both the ZF 5-speed and 6-speed transmissions....

I assume from your moniker that you are in Apex....