The ZF rebuild website calls for fluid replacement at 60,000 miles. I changed the pan on my XKR at 50,000 since it had the notorious chirp on the 3-4 shift. The fluid was very dirty and needed changing. When I changed the fluid in both the cars, all the annoying lurches and chirps disappeared. They work seamlessly like new. This means the trannys definitely had shot fluid friction modifiers in them. Get the stuff out of there as soon as you can. I also highly recommend using the Lifeguard 6 fluid.

 

Sorry Penguin - Miles

 

I have a 04 XJ8, 83,000 miles on it (not km). I am the third owner of the car. I live in South Carolina and drive it here back and forth to work and we as a family travel in it. The previous owners, one lived in Pensacola, Fl and the other in New Orleans LA. I probably drive that car 10000 miles per year. At times, I really get on it. I have reached top speed one time, burned it out one time, and the rest of the time i have owned this car I baby it (only to keep my suspension from falling apart). Is this harsh conditions or does it fall under normal conditions? So 100000 miles or 60K miles?

 

usmc1211 I would say anything that brings up the fluid temp up high for extended periods is harsh - towing is harsh - extremely high ourdoor temps is harsh - so I would say how you are treating the car is normal conditions, but maybe it was harsh prior to you owning the car - if it was my car I would consider replacing the pan+filter+ZF fluid asap.

 

My Car has been towing since new and the suspension has never had a single repair. It appears it has lots of overbuild so I would not worry too much about the suspension.

 

Would you recommend flushing the system or just replenish the fluid that comes out and not replacing the whole 10 quarts, since when you empty the fluid the tranny, only a fraction of the fluid drains?

 

I would say most important drop and replace pan + filter - remember electrical sleeve(It is aggravating to replace fluid and then the sleeve leaks short time after - you need to have pan off to replace sleeve). Replacing the fluid through the pan replaces 6 quarts. When you flush, the fluid goes in through one cooler line down in the pan/filter where the fluid is circulated - TQ and trans internal, and some out through the other cooler line. The part that does not go out in the other fluid line goes down in the pan. Some shops will flush until 10quarts has been reach others will stop as the fluid comes out clean - neither will replace the remaining fluid unless you flush 35 quarts through and in the meantime you have replaced the fluid in the pan all over again. Given a flush in my area (labor only) is 75 I have had a flush performed afterwards where the shop stops when the fluid coming out of the other cooler line is clean(2quarts - very subjective ). This flush replaces fluid in the cooler lines and some in the upper distribution in the trans. Hope this help