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I have invested around $6000 in not one but two of the A clutch drums and the labor that it takes to replace.
Due to not being mechanical and having to trust others to repair my car, I probably ended up paying more than anyone should have to.
The 1st drum replacement was found on Ebay. I directed the shop to the Ebay part which was supposedly an improved drum. They ordered it installed it and two years later it failed.
They showed it to me and also showed me the area that looked like it had been welded. I wondered after the fact why the shop installed it if they knew it had been rebuilt and welded. Maybe they didn't know... ?
This is the drum... the area that is separated was the welded area. I now assume this is what the web site meant by improved. The shop found a better one locally. It was new! I'm still not happy because now I am getting "gear fault" and "failsafe engine mode" messages on the console. I'm ignoring them for now because I need my car and it was at the shop for so long.
The 'A' drum failures have been definitively linked to pressure spikes caused by wear in the valve body. ZF has provided technical information on replacement. Therefore, replacement of the 'A' drum alone does not solve the problem and only sets you up for failure of the new drum.
Some have begun replacing the valve body as a preventative measure.
According to ZF, replacing the pressure regulator valve with the updated version will prevent the pressure spikes, if the bore of the valve body is not worn.
According to ZF, replacing the pressure regulator valve with the updated version will prevent the pressure spikes, if the bore of the valve body is not worn.
I would think that a tranny shop owner would want to know why this happens the first time and search for this info. He made a few comments about pressure and the TB but acted like he didn't want to go there due to the expense.
Expense is certainly not a factor, but this is something that had to com from ZF. The new valve is only different by about 1mm in the innermost section.
It cost less than $30 when I did it and took less than an hour after removing the pan.
Expense is certainly not a factor, but this is something that had to com from ZF. The new valve is only different by about 1mm in the innermost section.
It cost less than $30 when I did it and took less than an hour after removing the pan.
Preventive action on this matter has been on my mind from the day I bought my 1998 XJ8.
So you say the valve can be replaced without removing the tranny, right?
Should this not be something every XJ8 owner should do, in the same way we replace tensioners?
I have recommended this for two years now, and the BMW pdf was on Gus' jagrepair.com site for several years before that. Unfortunately, most Jag owners do not have time to read all the posts on the forum, or are unable to do the update themselves and are not willing to pay to have it done.
I recall one member saying that his mechanic considers himself to be a ZF expert and does not see the need for the update.
Is there any chronology of ZF's efforts to at least mitigate this problem? I ask because by the time my '02 was built this would appear to be a well known problem. Were there any factory modifications during this period?
I wonder if I should upgrade the valve body or take my chances.
I have recommended this for two years now, and the BMW pdf was on Gus' jagrepair.com site for several years before that. Unfortunately, most Jag owners do not have time to read all the posts on the forum, or are unable to do the update themselves and are not willing to pay to have it done.
I recall one member saying that his mechanic considers himself to be a ZF expert and does not see the need for the update.
Thanks for the head-up.
I don't really care what other members do, there are simply too many proven gearbox problems on this and other forums to deny the problem.
I will certainly research this further on credibility and do-ability, as I do not see why we should all change our tensioners, but not go one step further and solve the next problem in the waiting on these cars.
My car has done only 65.000mls, and has been babied by the previous (one) owner, so I have good hopes that with some extra care, I can make it last forever.
My 98XJ8 "front drum" aka A basket ( I gather) failed. In the pix above the inner component of the basket's teeth had sheared off. I held it in my hand while this was described. I was told the 2000's was beefed up. Luckily a great mechanic in ATL (Jag & Caddy of Northlake) put in a 2000 drum and things have been great since. Otherwise I would have scraped it. At the time I prayed it was a regulator, but no. I am waiting for the tensioner to go, but now I take it easier on it and warm it up before driving. Also, check your oil after each change at least every 500 miles. This car uses oil normally so gauge it and add accordingly as you learn the particulars of your engine. I feel pretty good mine is going to last, but I am about to get an XJR if I am not talked out of it.
I am waiting for the tensioner to go, but now I take it easier on it and warm it up before driving.
That is not going to help when your plastic tensioners fail and it could ruin your engine.
If you think the tranny problem was costly, wait until you are faced with spending $4000+ to install a used engine.
Why not fix replace the tensioners with the 3rd generation metal now before they hand grenade your engine? Cost is about $200 DIY and $600 for an indy to do it.
Vector
A few points on comments in this posting. I've had my 98VDP since buying it as an early lease return in 1999. Since then I am batting almost 1.000 on the commonly identified XJ8 gremlins:
* ECU re-flash for the flooding problem on Throttle Bodies in 98's and 99's (a recall)
* water pump
* tensioners & guides
* headliner
* tranny (A drum fail, not the F drum problem its also known for)
* Ft wheel bearings (replaced 2x)
* cup holder
* seat memory potentiometer (broke in 2003 but never bothered to fix this as the seat rarely moves)
* microswitch that controls the trunk lights
* brake pedal microswitch for cruise control
The only bullet I dodged was Nikasil as I bought the car in an area that always used low sulphur fuel (and am happy to have it, as IMO the cylinder walls will last virtually forever provided I avoid sulphur fuel - which is no longer being produced, so I should be safe.).
As I do my own work, the cost of ownership has actually been not bad. The most expensive work was the tranny rebuild as I also added a rebuilt Torque Converter (cost @ $1250 all in) so perhaps $3000-3500 over 16 years. As I got the car for a song (relatively) as an off lease machine at @ 1 year old, the mtce cost hasn't caused me a lot of grief.
So from my experience:
The engine does not normally burn oil. I have been active on forums since the car was new (to me) & the only references to oil use have been from people with problems. In the early days this was Nikasil related, later it was the usual things that go wrong with older cars. I have 160,000 miles on mine and it has never used any between changes. If one does use oil, it has issues (but they may not be sufficient to worry about & if they are you likely already know that....).
Tensioner changes and upgrades seemed to have happened at any point in the production run, so whether you have gen 1, 2 or 3 in your car I don't think you know until you open it up, other than generically knowing gen 2 started being used in late 1999 or so & gen 3 by 2002. While gen 1 were problematic (when I did the change in 2004 at 107,000 miles, I found mine had minor cracks in the plastic housing, but were still OK but my guide rails were worse with chunks missing - & they never got a design change AFAIK), I haven't seen many, if any, reports on gen 2 fails.
The important thing in understanding the inside of your tranny is which ZF version you have installed. In the XJ line, there were at least 5 versions used over the years (see extract from the ZF catalogue below). The catalogue is dated 2003, so why it stops with the 99 MY for the 8 cylinder cars is unclear. Perhaps the last version ZF used in the XK & XJ8 was the 027?? Regardless, you can see the tag from below (drivers (left) side as I recall)
When I did my tranny rebuild, I found the updated pressure regulator (& perhaps more importantly springs) that replaced the one identified as being problematic started being installed in the VB sometime in the 98 model year, perhaps when the 024 version started being used. However, the principal issue contributing to faults appeared to be scoring of the cylinder walls in the regulator housing allowing fluid to leak by the regulator. How / why this happened, I never found out, nor could I tell if the design change in the regulator was to address this. The only way to tell is to pull the VB and measure / compare the parts & look for scoring (as far as I could see on mine when I did my tranny job, there is no p/n stamped on the regulator). NB this applies to all types of cars using the 5HP24, not just Jag
ZF changed out the entire upper VB housing starting with the 026 version, so sometime around the start of production of the 1999 model year. However, folks have had tranny fails after this, so clearly the changes didn't address the root cause. NB this applies to all types of cars using the 5HP24, not just Jag as the VB is common to all.
The revised A drum seems to have been introduced in a least 2 steps. The exact date, I could never determine as the p/n was never changed, so the change does not seem to line up with a variant #. However, it seems that by about 2001 or so, the last version was in production, but I have seen reports on the Bimmer sites that the old version was still being provided as a spare by ZF well after that. The changes to the new version were a beefed up outer ring and an added oilway. NB that Not all aftermarket seem to be compliant with the mod to add the oliway (the one I used didn't have it) & I have seen reports of original style A drums being sold on E-Bay as recently as last year. NB this applies to all types of cars using the 5HP24, not just Jag as the A drum is common to all.
I'm in the middle of rebuilding a '98 tranny, replacing the a-drum. could someone please help me identify what part of the valve body is the pressure regulator, and maybe a link to the how to replace instructions? I haven't reinstalled the valve body, so I apparently read this thread just in time!!
This pdf shows the location. For r/r of the valve it is wise to use a couple of bar clamps on the cover plare to keep the springs from flying out. An extra pair of hands is also good.
XJ8 Tranny: A Warning!
