XJR 5 speed auto

[mpkayeuk]

Hi Guys,

My Jaguar XJR has a Mercedes 5spd auto. I am told that the XJR was fitted with an Merc box because it was the best box available that could handle 370BHP and 390ftp/lb of torque.

The car has now done just over 90k miles and I suspect the autobox has never been serviced. It seems to slip between gears and sometimes misses downchanges (very very jerky requiring 2 repeated attempts before it gives up and throws an error to the console and sticks in one gear).

Any ideas what the problem might be? Your help is much appreciated.

 

[Francois]

The first thing is always to check the gearbox oil level.

Make sure that it is at the mark on the dipstick at OPERATING tempreture.

 

[mpkayeuk]

I don't have a dipstick in the engine bay. At least, if it's there, it is very well hidden. I do have a little electronic cover, looks like a sender plug with, "For MB Service Only" written on it. No idea what that is. This is a Supercharged 4.0 V8 Jag though, so maybe not configured the same way as the Mercs this box is fitted to.

 

[mpkayeuk]

After having done some more research it appears that the box fitted to my XJR is a 722.6 all electronic MB gearbox.

So, what might cause the above symptoms? I have it booked in with a local autobox specialist on Saturday for a general look and a filter/oil change. Is this likely to make any difference to the box, or am I looking at a warranty claim?

Cheers,

M

 

[Spike]

Has the gear oil ever been changed?

MB says its sealed for life but many disagree and plenty of people have commented that a gear oil changed did wonders for the behaviour of their auto boxes.