I recently rebuilt the transmission on my 98 VDP at 145K miles (230,000 Km) to repair a bad A drum which had broken at the snap ring groove allowing a 3" piece to separate. In turn this caused the A clutch (used in Gears 1 thru 4) to be unable to hold pressure.

With the exception of metal fragments embedded in the frictions in the A clutch, I found no other damage. I was unable to detect or measure wear in any of the bearings, frictions or steels which I thought was impressive after the miles put on the car.

I've built a lessons learned doc for some other forum members which I'd be happy to forward on to anyone contemplating doing a rebuild.

Some highlights:

I also replaced the Torque Converter in the hope that it would help correct a driveline vibration that has been present for several years after having read about similar symptoms to mine being caused by a bad lock up clutch.

Total cost (shipped and taxes paid) was $1250 broken down as:
• Rebuild Kits $466 (ZF rebuild kit, Frictions kit, new F piston and filter)
• A drum $154 (aftermarket new design)
• Torque Converter $412 (rebuilt)
• ATF $84 (I used Castrol Import Multi Vehicle rather than the Esso)
• Fasteners $11 (to replace damaged heads on several)
• Taxes $125 (required to be paid on the shipments received from the US)

As I live in Canada and the kits, A drum and TC came from the US, shipping (included in the costs) was a big part of the cost @ $175 of the total. Most of this was the TC due to its weight.

The actual rebuild job was relatively simple. The most complex part was removal and re-installation from the car, made more difficult as I was: a) working alone and B) working with the car on blocks.

I have read of some completing the repair without doing a complete tear down and re-assembly. My experience was this approach would have been a mistake as I found shavings and chunks of metal in several places in the transmission and valve body plus the residual fluid was contaminated with suspended metal particles - which I'm sure would have resulted in another failure failure quickly if they hadn't been removed.

Fingers crossed, so far I'm v happy with the result. The transmission shifts as always and the new Torque Converter appears to have cured the driveline vibration as well as occasional harsh downshifts I think were caused by the lock up clutch in the TC failing to release.

 

Sounds like the end result was as good as or better than a rebuild from all but the best shops.

Your document may be of interest as a permanent download if you so desire. How big is it?

 

Plums

Happy to do that - I hadn't thought of an attachment. I have it as a PDF doc at 1.6 Mb. Later today I'll look at uploading it. If its too big, I'll break it into smaller chunks.

Scott

 

Nice job! I'd like to hear some details about how you blocked up the car (how high?) and any issues with getting the transmission out and in. If I ever have to do this, I will be doing it myself also and would want to be prepared!

 

Good job, Scott. I think you made the right call on tearing it down, and it sounds like your problems are over.

 

Thank you Scott for the post. My 01 XJ8 is just starting to chatter and sometimes jerk when accelerating from a stop. It has the same zf5hp24 and probably a drum problem as well. I'd sure appreciate that doc if you could point me to it.
Bill

 

Did you address the valve issue that has been reported to be the root cause of the 'A' drum failure? I was unsure if the 'F' valve mentioned in the parts referred to this valve issue. If it was, how did you deal with the valve body wear? This was discussed in a few days ago on this forum: https://www.jaguarforums.com/forum/x...e-valve-88615/

 

The F drum houses a clutch in the transmission, so no relation to the piston in question.

The reference to the main piston in the VB refers to an upgraded part introduced by ZF at some point in the transmission life cycle (I just don't know when). My understanding is that there have been cases where there was scoring of the bore which allowed fluid to leak past and caused pressure spikes. These have been indicated as a cause of drum failure, although I can't speak with certainty that they are or aren't. I don't know that there are any detectable symptoms of a piston scoring, so a visual inspection may the only course of action if you are concerned.

In my case, I ordered the upgraded piston on spec as I was doing the rebuild, but it was missed on the order. When I disassembled the VB to clean and inspect it, I found no scoring of the bore, so elected to remain with the old unit. As I indicated in my writeup, I couldn't even tell from the info if I had the new or old variant installed as there was no p/n on it I could find.

As a replacement item it would be easy to change out on its own. The VB can easily be removed once the pan is off the tranny and once benched the process to replace VB components is straightforward.

Hope this helps. ANy questions drop me a line.

ps - the car now has some 2000 miles (3200 km) on it since rebuild and all is 100%.

 

Bill

The writeup is posted at https://www.jaguarforums.com/forum/x...nce-how-82302/

If you have trouble getting it, send me a PM and I'll send it to you as an attachment.

regards
Scott

ps - to close the loop on the question from Test Point, I found no wear on any element of the transmission and ended up concluding the failure was due to fatigue. As the A Drum redesign thickened the lip area where the failure occurs (& added an oil way as far as I can tell), I think this is the solution ZF implemented to resolve the problem.

 

Thank you for the great write-up. I am curios how your rebuilt transmission has held up now that some time has passed.

Also, I am needing to rebuild the tranny on my 1998 XJ8. I was wondering if you could devulge your sources for your Rebuild Kit, A Drum and Torque Converter? It seems like you got some very good pricing.

Thanks for your help.

Manfred

 

Manfred. The car has done 7,000 miles (@11,250 km) since the rebuild, with no subsequent issues.

I sourced the rebuild parts off e-bay. A quick search using ZF5HP24 seems to show many sources including the one I used (I used the ZF kits, not aftermarket, but am not sure it makes any difference & prices are similar).

The torque converter I got of a google search. Same search today shows lot of vendors with rebuilt units at good prices.

Prices all seem to be in the same ball park as when I did the job.

Good luck & any questions, drop me a line.