Advice needed for newby to Jags

[LDK]

Hi all, bought my first Jaguar last week,1999 Xj8 3.2 145000miles but has not done more than a 1000miles in 3-4 years  for not a lot of money so I am expecting some issues but! does anyone know if there is a definitive answer to a failed rear differential???

 

Symptoms

Very slight rumble from rear at 30+mph only when accelerating. 

At 45+mph loud rumble and nasty vibration (shakes car) when accelerating but stops if I let off and cruise 

In sport mode the same happens but at 50-60mph

NO metallic crunching or banging 

What I have tried to check

No fault codes or dash warning lights

Wheel bearings on rear have got some play (ordered new ones) 2mm play

Wobbled all drive shafts and no sloppy moving parts 

Greased all joints as they where dry

tyres seemed ok

My guess with very limited knowledge of these cars

Prop shaft out of balance

Worn UJ joints

(hopefully not.....GULP!!!) diff

and the wheel bearings are definitely a factor but not the big vibes and rumble

 

I took it to Essex Jaguar Spares in Upminster, does anyone have any experience of using them for servicing and repairs. they seemed happy to help but recommendations would make me feel happier using them.

 

HELP!! :(

 

 

 

 

[msmicksmith]

I'm not familiar with that particular model but with what you've mentioned I'd be inclined to check the prop shaft bearing (if it has one, which I'm sure it will). If that is ok then the rumbling and vibration has to be either diff related or driveshaft/ bearings.

Prop shaft bearing would be my number one to check

[msmicksmith]

You can check UJ's by checking if the two sections of prop shaft can be moved in opposite directions from each other. Lift the rear wheels and make sure the handbrake is off and you're in neutral. Then grab one half in one hand and the other half in the other hand either side of the UJ and twist. Any movement indicates wear. They should be rigid

[LDK]

Thanks JimC64 and msmicksmith for your comments.......definitely the first thing to address will be bearings and fluid levels/change, this is booked in for Monday! I found out today that if I put my car into manual 3rd gear the car runs up to 70+mph with no vibes??? As soon as I select 4th and accelerate the rumbles come back and shakes the car??? Ease off the throttle cruises good. So I think not the diff gearbox but no faults or lights on dash and with my OBD2 "cheap one" no fault codes either!!! Very strange.....I don't know it's going in Monday so I will throw myself at the mercy of the mechanics :)

[msmicksmith]

I'm going to hedge my bets and go for prop shaft bearing.

Please put me out of my misery and let me know ;-)

[LDK]

I will post all the findings as soon as I find out.

Hopefully won't need to remortgage to get it fixed lol

Kind regards

Liam

[LDK]

Well got my Jag back.......differential needed replacing and now it's all done it is super smooth!!!!! All gears work, sports and standard mode work too, no rumble, judder so very pleased :) BUT £700.00 fitted!!! Ouch!!! So hopefully sorted XJ8 for £1500 isn't to bad.......as long as nothing else serious needs replacing.

[msmicksmith]

Nice one. I don't mind being wrong, I was diagnosing over the internet! ;-)

Enjoy your super smooth Jag!