My '03 XJ8 hit 100K several months ago and ever since, I've been worried about the dreaded A drum failure. (I really like the car and want to keep in for the long term). I was intending to do a transmission service over the winter, but had the opportunity to take advantage of a visit from a good friend who works from Ericsson Industries in CT and rebuilds ZF transmissions for a living. While not the ideal time of year to drop a bunch of money into the car, I decided to bite the bullet and buy all the needed supplies and parts to do the service and take advantage of my friends expert knowledge.

I bought a new filter, gasket, drain plug and pan hardware, along with 11 quarts of the ultra-special ZF transmission fluid ($25/qt retail) and a remanufactured/upgraded valve body. Fortunately, I have a pretty well equipped workshop/garage with a lift, so we hit the shop at about 9:00 on Sunday morning. We worked around the shop while the car cooled off and started the procedure at about 10:00. We were done at 2:30, but would have been done sooner if we didn't have to go searching for the correct torque wrench (details below).

After disconnecting the battery, the drain plug and pan bolts all came out except for 2 pan bolts at the rear of the pan. One eventually came out as a result of shocking it with a brass drift and a little more leverage with a cheater bar. The last one resisted all attempts and the torx head began to fail after a while. We ultimately ended up chiseling a notch into the bolt and used the chisel and hammer to break it loose. Once loose, we took it the rest of the way out with the torx bit.

When we dropped the pan (and after a shower of warm tranny fluid), we were happy to see that there was very little metal in the bottom of the pan. There were no metal chips or filings and the four magnets were coated with a smooth metallic paste. We removed the speed sensor and it too was free of any metal filings. (It sits next to the A drum and if it starts to fail, bits of metal can be found on the speed sensor too). We unbolted the old valve body and then let everything drain, while we laid out all the new parts and cleaned the pan, gasket surfaces and magnets.

One thing that we needed was a torque wrench that was calibrated in inch/pounds. This is essential for making sure the valve body is torqued down to the proper specs to work correctly. If you don't have a torque wrench that reads in inch/pounds, you can use one that reads in foot/pounds, but it has to go down particularly low so you can convert from inch to foot/pounds. This was a problem, because despite my many, many tools, I didn't have the proper torque wrench and none of the big box hardware stores or national auto part chains carried anything that would work. You will need one that reads as low as 70 inch/pounds. Despite the pain, I had to buy a digital torque wrench for $190, that reads in ft/pounds, inch/pounds, Nm and angle. A great tool, but a lot of money for a simple (but critical) job. Plan ahead and get a mechanical one from Amazon for about $45.

Once the proper tool was acquired, we started the reassembly in reverse order, hand tightening the bolts first and the torquing them to the proper spec. (Hint: before putting the pan back on, be sure to crack the fill nut on the passenger side rear of the transmission housing. It will be a b*tch, as the exhaust pipe is in the way and as a result, it's tough to get good leverage on it. Small extensions, a breaker bar and a cheater pipe may be needed. Just be sure the hex bit is firmly and squarely engaged in the fill nut socket).

Once everything was reassembled and the battery was reconnected (Take the time to clean the posts, reset the ECM and coat in dielectric grease), we filled up the transmission using a 5 Gallon lever pump that we got from Amazon. We started with the bucket filled with 8 quarts and filled the transmission up until it began to dribble out the fill hole. We then started it and let it run in Park for a bit, adding more as we went. We shut it down, added more fluid to the bucket and then started the car up and shifted it into Neutral for a bit, then back into Park. Shut down, repeat, then we ran it through the gears with the engine idling. We rechecked the fluid level and then closed up the fill plug, took the car off the lift and took it for a test drive.

I am happy to report that the car shifted quietly and smoothly and downshifted as it should, with no hesitation or harsh shifts. We put the car back up on the lift and checked the pan for leaks and all was good. In the end, we used about 7-8 quarts of the ZF fluid. I have a few quarts left over for top offs if needed.

This type of transmission service and upgrade can definitely be done by an owner with good mechanical skills, patience, attention to detail and the right equipment. As a result, you can save a boat load of money over a dealership or even a local mechanic. It's also great to know that the transmission is in great shape and ready to go for another 100K.

 

Off topic but WOW- this guy has a Rover P6! I didn't think they were sold over here. When I was a kid in London the police used either those or SD1s and they were all over.


Anyway- well done with the tranny build! I'm not sure I'll tackle my W5A580 myself, perhaps when it's time, I may use better materials from the Chrysler hot rod fraternity along with the AMG blue top solenoids

 

Hey Count! They were indeed sold over here in the US along with their V8 counterpart the 3500S. (Those were typically UK Police cars). There is a small, but fiercely loyal fraternity of P6 owners in the US and Canada and several clubs dedicated to them or the Rover brand in general. They are great, well-engineered cars and my '69 is an excellent example of the breed and a real pleasure to drive.

With respect to the transmission service, I wouldn't go off the reservation and start putting other parts in a perfectly good ZF transmission. They are pretty well designed and most weaknesses are easy to address for the competent DIY mechanic. If you were closer, I'd offer to assist.

 

Do the AMG blue top solenoids make the XJR Mercedes transmission shift faster??

 

Yes, they make it shift faster and firmer but only at light to mid load

 

Does anyone know how much this service would cost if brought to a transmission shop?

I see that the fluid is stupid expensive.

If I bought all the parts, how many "shop hours" does the manual say it takes for this type of tranny service?

 

Hi LeLimoMan,

Congratulations on a successful transmission service, and thank you for taking the time to share the details. Your post will be helpful to other members for years to come.

I just wanted to add a few bits of info that may help others who are planning similar service:

As has been widely shared on the Jaguar Forums, Lifeguard 5 is ZF's brand name for ESSO LT 71141 fluid, which is available from other sources at lower prices. For example, I used Febi Automatikgetriebeol (ATF) Nr. 29738, which is also sold as VW/Audi G 052 162 A2. Other suitable fluids include Pentosin ATF 1, and Ravenol ATF 4/5 HP. For the Febi fluid I paid USD $49 per 5-liter jug with free shipping from an eBay seller. I bought 3 jugs and used about 12 liters to completely flush the fluid via the cooler lines.

An important consideration is that torque wrenches are generally rated "accurate" only from 20% to 100% of their range. The ANSI standard is 4% accuracy within this range. According to Snap-On, their torque wrenches can be off by as much as 16% when used in the lowest 20% of their range. Obviously, lower-quality wrenches can be even further off. So if you use a torque wrench with a common foot-pound range, such as 0-75, it is only considered accurate above 15 ft. lbs. But 70 inch-pounds is less than 6 foot-pounds, so you would really need a torque wrench with a total range of, say, 0-25 foot pounds, which is not common. Better to buy, borrow or rent a proper inch-pound torque wrench, ideally one with a range of something like 0-75, 0-150 or 0-250 inch pounds.

Most workshop manuals and experienced mechanics recommend loosening the fill plug before the fluid is drained, so we don't have a half-empty gearbox and no way to refill it.

Thanks again for the great post!

Cheers,

Don