Ok, I know the XK8 transmission is supposed to be sealed for life, but we all know there is life after 80k miles. I figured that having the fluid changed and screen (filter?) cleaned out would extend the life of the transmission, but the dealer service rep tells me this is not necessary until the car shows signs of slipping shifts, etc. or some other indication that the transmission needs attention.

I'm new to Jags, but this seems counterintuitive. At the same time I don't want to take this down to AAMCO as it is likely that they know nothing about the car.

Thoughts?

 

Many will tell you it is a good idea and the same amount will tell you the opposite and to leave it alone. I had it done because I believe in preventive maintenance and shortly after I had a failure and the a&b drum had to be replaced. You should know that this is type of failure is not uncommon with this transmission and not with just this car, this trans is used on others BMW is just one of the many. After my failure I asked my transmission mechanic if changing the fluid (servicing) could have caused the problem and he said no. Do I trust his judgment? Yes!

I am providing you a link https://www.jaguarforums.com/forum/s...ad.php?t=31553 for you to read the many comments from a poll that was taken on fluid change and trans failures, I hope this helps.

 

I'd ask for the service anyway. If you want to be REALLY preventative, do the a-drum replacement/rebuild at the same time...kill two birds and all that.

Gus is also pretty keen about the rebuild/refurbished details, so ask more if you need to about that.

 

ZF now recommends a 60k mile ATF/filter change for the 5HP24 transmission that they would supply as a factory rebuild.

I think I will go with them since they designed and manufactured the transmission.

 

I am at 75k on my 97 and pretty sure trans is orig. Operates as it should at this point.

 

Makes sense to me. But where did you see this? I couldn't find it on the ZF web site. Not that I don't believe you, but it would be nice to have something in print.

 

I wouldn't worry about the print! New trans for mine @ 107K because I listened to the dealer. I tell you, a fluid change, although expensive is still cheaper than $5 + K for a trans and install.

 

BMW now allows dealers to change fluid on their 'lifetime fill' ZF units at 100,000 mile mark. Prior to that, they would not change fluid on a customer's car. In fact, their service manual instructs techs to save fluid and re-fill the trans with the old fluid. How dumb is that? This trans is basically same as our XK8.

 

I changed mine at about 65k (fluid and filter) at an independent Mercedes/BMW shop for about $300 with the proper Esso oil. The dealer will probably want alot more, but it's not rocket science. Check around the German repair shops, they're very familiar with our transmissions.

 

So it seems on my 97 XK8 with now 77k it would be wise to have the trans fluids changed?

 

Yes, perhaps you should spring for an ATF replacement.

Maybe even the filter after 13 years.

 

Mines the ZF6HP26 6 speed gearbox and couldn't find an Indy who had the correct oil or was prepared to buy in 25/50 gal. So had to go to main dealer. Cost about £400- including pan/filter. At least, in my case, it's a one off.
2003 4.2 87000mls Midlands UK

 

I've done oil changes on a few 6HP26s now including my own. I strongly recommend a 50K mile oil/filter/pan/sleeve change.

On 6HP26s there are some additional issues that come up fairly frequently at about the 50K/60K mile intervals. The pan is plastic and often develops a leak because of warpage. Also, the 6 speed ZF has a plastic sleeve that enters the transmission at the place of the selector electronics (right above the oil level plug. These begin leaking pretty regularly at about the 50K60K interval, so if the pan doesn't get you the sleeve will. The filter is an integral part of the pan, but you'll destroy the pan anyway trying to get the 21 bolts out.

To do this job you need the pan/filter/gasket, the sleeve, 21 new bolts (trust me one this one) and fluid. I now only use Mobil 1 syn ATF unless the owner insists on Lifeguard 6 which is about 4 times the cost.

 

Thanks for the info. A few questions -

What's the sleeve?

I assume on a 5HP24 that changing the pan is not necessary, since it's metal?

Are you suggesting you break bolts every time you remove the pan?

 

The sleeve is a plastic part with O-rings that seals the outside electrical connector that plugs into the internal electrical that controls gear selection.

The 21 bolts holding the pan in place are 6mm with an odd sized #27 torx head. These steel bolts seize themsleves into the aluminum case (aluminum and steel do not chemically mix well). The torx size is too small for the amount of torque needed to break the seizing. You will strip at least half of the torx heads, the other half is called lucky. On the half that strip, I usually end up grinding a slot in the head and using a large flatblade screwdriver to reomve them. Then, at least one will snap off completely. Here too, if you're lucky, enough screw body will be left to grasp with vice grips. The replacement screws use a larger torx head, a #30, if I remember, and I assemble with a generous amount of anti-seize compound.

 

I just get a little worried that doing so this late in the trans life could just end up killing it sooner then if I'd left it alone. I have had a trans do this to me before. Changed out the ATF and filter and a little later down the road trans bit the dust.

 

It is highly unlikely it was the fluid change that caused the failure, assuming the change was done correctly and the correct fluid used, but I can understand your confidence is now rattled. If it were mine, I'd change fluid/filter immediately or yesterday whichever comes sooner.

 

I wouldn't disagree that an oil / filter change before 100k is a good idea, but the most serious 5HP24 failure mode on early XK8s is a fatigue failure in the 1st/2nd gear clutch pack as I've mentioned in the 'poll' thread. No amount of oil changes is going to prevent that going pop..... however less shot journeys and not dropping into N or P at the lights will help as it reduces the number o shock loads on the pack when it pressurises.

 

With this problem a major difficulty, I would suggest starting a little earlier and applying Kroil or Aerokroil to the screws so that they will unstick, this would make the job a lot easier. If I thought I would have to go through breaking off screws every time, I would hate that job! By the way, when you change oil and filter, do you use a flusher and change all the oil or do a 5 qt drain and refill? I am getting ready to do this on my 06 XKR and my 05 XJ8 and need to get going bringing together the materials.

 

If you're doing a 6HP26, the dry fill is about 10 qts with an additional half qt. in the cooler. On the drain, you'll yield 7 1/2 qts. That's over 70% of the fluid drained. I only drain once as the new filter is going to immediately start cleaning up anything left in the 29% old fluid.

I know several people with BMWs who do an additional drain refill, oil only, not filter, but I'm in the camp it is a little overkill.

On the frozen bolts, I am unable to wait for a penetrating oil as turnaround time is usually the priority. I believe it is not going to work on these bolts as you're trying to get penetrating oil past a very large bolt head and hopefully wicking upward on a vertical bolt with a tight plastic seal (oil pan) trapping the thread body. If the penetrating oil can get to the thread body, then you probably are leaking transmission fluid too.

If you're doing the ZF 6 speed the ZF part numbers for the parts you'll need are as follows:

Pan/filter/gasket assembly - 0501-216-243
Guide Sleeve - 0501-216-272
Bolts (21) - 0736-101-486

As far as I know, all three of these parts are universal for all 6HP26s. I haven't done a Jaguar newer than an 05 though, so I haven't really researched newer models.