Gearbox noise pulling away

[simon291971449]

HI
Just purchased a late 91 facelift, and during my first drive - to MOT station - I noticed a short grating noise from the auto box when pulling away. It only happens when I put my foot down a bit for a slightly quicker get away. If I just ease away slowly, there is no noise. Any thoughts/explanations would be welcomed.

Thanks

Simon

[davidr]

Hello Simon and welcome. Sorry to hear you're having troubles.
You don't say which model you have. 4ltr or V12?
In both cases the initial steps would be the same I'd say.
Firstly check the transmission fluid level and condition. If it's very low that may be an issue. If the condition of the fluid is poor that may also be a factor. What you're looking for is clean red fluid. If it's brown, dirty looking or has a burnt smell then it won't be doing much good.
A change of transmission fluid and filter can work wonders and is always worth a try before anything more drastic.

[ptjs1]

Hi Simon,

Welcome to XJS ownership!

+1 for David's suggestion for fluid and filter changes. Really worthwhile on these boxes.

Also, are you sure it's coming from the box itself? There are a couple of other things it could be:

- Discs scraping against pads, particularly if car unused for a while

- Driveshaft protection covers scraping

- Engine fan touching top of fan shroud. This can happen if transmission mount is worn. Under urgent acceleration, the box drops, the engine front end rises and the fan blades scrape the shroud. If this happening, you really need to check it to avoid fan damage which can get expensive!

Good luck

Paul

[PaulGover]

And another possibility - failed rear gearbox mounting. It's a single spring surrounded by a foam bush to centralize the rear of the engine & gearbox assembly. If it's gone, (and it dissolves in engine oil!) under high torque the box can move to vibrate against the gearbox tunnel. Ditto if it's misaligned (then even if the bush is still OK, it can make noises).

[simon291971449]

Hi folks

Thanks for your replies. It was the gearbox mounting. All sorted.

Simon