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Morning All,

Just recently, when putting the car into Drive, the normally smooth & quiet cabin is interrupted by a mild vibration that isn't there when the car is in Park or Neutral. I can feel it through the steering wheel and gear lever. It's not violent but I'm certain it wasn't there before.

As we get up to about 45 - 50 mph, there's a whine from the transmission. This disappears on overrun.

I know this is a MB gearbox and I had the fluid changed about 3,000 miles ago by a good independent Jaguar workshop. I don't know if the procedure included the kinds of things that a ZF fluid change would (filter, sump pan, etc).

I'm wondering about the torque converter (my X350 SV8 is currently at Bristol Transmissions for a TC replacement and gearbox rebuild so I'm really worried about the Daimler now!).

I'd like to check the fluid level but I haven't got the dip stick (yet).

Any ideas from anyone?

Many thanks,

David Q

David Q,

As is always the case with these boxes, if you do a standard fluid change, you'll only drain a percentage of the total fluid contained in the system which has a T/C and oil cooler and pipes in addition to the fluid in the box.

I don't know the history of your car, but unless previous owners were absolutely diligent about the way and mileage in which they did fluid changes, you could still have quite a lot of old fluid and sediment sitting in the system.

Therefore, I would start by doing another fluid change. (You can choose whether to change the filter again or not). At least this way, you'll have a lower percentage of "dirty fluid" after a second change. You could even run that for 10 miles and then do a 3rd or 4th change. As your Super V8 uses a MB 722.6 box, the fluid is pretty cheap compared to the LT71141 fluid in the ZF 5-speed box.

In my 4-speed XJS ZF box, I do 5 oil changes as a simple fluid drain only pulls an absolute max of 30% of the total fluid.

So, just do a few more changes and see if the situation improves. That fluid is cheap, whilst a gearbox and T/C replacement is expensive, as I'm sure you know!

Good luck

Paul

Hi Paul,

Thanks for that. I'll get it booked in after the festivities for a couple of fluid changes.

I know the T/C hangs on to a load of fluid so it will be a good idea to flush some more through. As an aside, the Jaguar SV8 that is having a rebuild had some detritus in the fluid that had probably come from the T/C which they think was beginning to break up!

As you say, fluid is cheap compared to a rebuild!

Thanks,

DQ