I drove back into my garage to see an unusual puddle of oil on the floor. After a bit of detective work I noticed the Rear Differential had an oil leak where it adjoins the prop shaft.

My question is how can I go about repairing this without too much bother and $$$ ?

(i also noticed all of my bushes are shot, Yup every single one of them.... )

 

This technique may buy you some time and stop the dripping. Clean where the shaft and seal meet with a thin rage to get in there nice and good all the way around. Take some wheel bearing grease with your finger and firmly press in into that area all the way around. If you are having a splash leak from a wearing rubber seal this should help. However if your shaft is getting worn and has a vibration to it, a seal replacement is the only way out of this issue that I am aware of.

 

I suppose a seal replacement means dropping the whole diff and propshaft? Which means a proper lift and tools and time?

 

Here is what the "What to look out for in an X350 - you need to know!" Section says.

Driveshaft / Propshaft center bearing & couplings
After 120'000 miles or so the center bearing in the propshaft tends to get a little loose, giving a slight "thud" when you get on & off the throttle. The center bearing cannot be replaced, only the entire prop shaft.

The rubber couplings at each end of the propshaft should also be changed preventatively after 10 years, as the rubber will perish with age. These are not available for the X350, but the S-Type ones are identical.

Hopefully someone can chime in on how to access which issue you may have and the steps to fix.

 

Hi trosty,

I'm not positive about the X350, but on many vehicles, including our '93 XJ40, it is possible to change the differential pinion (input) oil seal without dropping the rear suspension and differential from the car. You just need to disconnect the driveshaft/propshaft and remove the pinion shaft nut and flange from the diff. The critical part is to return the pinion shaft nut to its exact original location, or just slightly tighter, because the preload on the pinion bearings is critical for zero play and long bearing life. The X350 Workshop Manual may contain instructions for replacing just the oil seal, but if not, I think the XJ40 Haynes Manual does (it's available in the XJ40 HOW TO LINKS thread - scroll down and click on Downloads).

If the pinion bearings themselves are worn and moving in ways they're not supposed to, the rear end and diff will have to be dropped for a rebuild or replacement. If you disconnect the driveshaft from the differential, you may be able to feel any movement in the differential flange. If there is no movement other than rotational, then you can probably just replace the oil seal, drain and fill the diff with fresh fluid, and hopefully drive the diff for years to come.

You can also drive the diff as it is as long as you keep the diff fluid topped up and it doesn't begin making noise.

Cheers,

Don

 

Thanks for the info.

As always, doing the actual work on the car isn't really an issue for me except for anything under the car (shocks, bushings, exhaust, Differential. transmission) that I can't get good access to because I don't own a lift. Ramps and jacks can only get you so far.

Also why is the filler plug in such an awful location and hard to open, I shall have to buy a special tool now for that one task as well I suppose, unless...... (thinking cap on!!).

You know sometimes all these little things going wrong and $$$ adding up just makes me want to get rid of it and buy something different, which is sad because I love the car generally.

 

Hi Trosty, how did it went with the rear differential oil change? I have done rear differential on my Mercedes, and it is relatively easy but I have to agree with you getting under the car without a lift really kills the back. What special tool did you need for the job? I plan on doing the rear differential job next weekend. I will tried to record the process so other members can see it.

 

Replacing that diff oil seal shouldn't be too big a job at a Jaguar specialist, there is a process as outlined by Don B that I remember reading about some time ago.

Of course you can just live with it if there is no diff noise or vibration and put a drip tray under it. You could also try one of those wonder "cures" in the oil to revitalise the oil seal a bit.

I was told at the last service my sump gasket was starting to weep, but when I asked about it was told it would be OK for some considerable time, although when that time came it would be £300 ! So next service in 2015 it'll be looked at again.

Sorry to hear about your suspension bushes, it sounds like your car has lead a hard life, or the previous owner just ignored what the mechanics told him. Eventually it all adds up and becomes a big and expensive job.

 

Its not as big a job as you might think if you undo the rear rubber coupling it should give you enough room to to get the flange off

the only problem is these jags use a crush tube to give pinion pre-load so once its undone you probably should order a new crush tube when you order the seal I would do that just to in case inspect the rubber flnge as well if its cracked or hard change it
I have attached a link to Bernard emdens v12 pages Differential Pinion Pre-Load Adjustment. he made his own tool up to allow him to remove and replace the seal might help if you are handy

You could also add some gear oil stop leak there's a few on the market just type in gear oil stop leak PermaTech - Fast and Easy 2-Part Head Gasket Repair Sealer- Oil Stop-Leak Sealer Page
I personally would try the stop leak its the cheapest option if it doesn't work you can always do the seal after

 

Did the rear differential fluid replacement today. There is just a fill hole only. So basically remove the nut, then get a small pump to get the fluid out. I pulled out a little over a quart of very dirty oil. The oil are very dark. I then use the same pump to add about 1 1/4 qt of fresh fully synthethic 90-140 oil until the oil over fill out. Put the plug back and it was done.