My 04 xjr is more and more often flashing the gear box fault message. Usually after fast acceleration or sometimes for no reason. Coming down to a stop it will hunt for a gear then lurch into safe mode. All i have to do is pull over, shut it off and restart and everything goes back to normal...
I know its been talked about on here that you should flush the system. ive called the local jag dealership here in shreveport aswell as the ones in Dallas Ft Worth and they all insist its "lifetime sealed" and they never ever work on them. I dont beleive them.
Is this something i can do myself? I dont have any special machinery. Does something in the cars computer need to be reflashed or remapped?
I dont mind getting dirty i just want to get this thing corrected so it doesnt eat itself. I imagine a new transmission exceeds the NADA value by now lol

 

Sounds like the fluid might be low. When was the fluid last changed or topped up?

You are right to disbelive the dealers.

Scan for codes for more information.

I would change the fluid first and ensure that the level is correct.

It's a bit of a procedure, which you need to research but have a tx specialist do it for you

if you'r not happy about DIY.

I stuffed mine up-please don't ask for details about that!

The procedure and parts needed is available from the California transmission people.

 

ZF, the transmission manufacturer, actually changed their advice a few years ago and now recommend that the fluid is changed every 50,000 to 75,000 miles.

I would avoid an official Jag agent on this one: i) they charge the earth, ii) they probably do one every alternate blue moon. As meirion says, use a transmission specialist, they do 'em all the time.

 

Here's a YouTube video produced by ZF:

 

It does sound like it could be a low fluid situation, but I would do a full fluid exchange when fixing the level. The pan or the cooler lines could be leaking.

 

see this reference from Valvoline for compatible ZF6 fluid. If you decided to DIY flush.

Valvoline Max life ATF.

http://www.carquestprofessionals.com...%206.10.13.pdf

 

here's another link

http://content.valvoline.com/pdf/maxlife_atf.pdf

 

I would beware that if I were you, it says it's a suitable substitute for Mercon SP and Mercon LV. However Ford say LV should not be used where SP is specified. Ford only specify SP for the ZF 6 speed box and their versions of it.

There has been considerable debate about other fluids cheaper than Lifeguard 6, and the only one with viscosities close to LG6 is SP; LV is distinctly different.

Looking at the viscocities Maxlife seems far nearer LV than it does to SP.