DB9 Juddering from Rear Wheels

[thomr]

I am getting a juddering from the rear wheels of my DB9 when starting off at a T-Junction. I get it all the time when starting off and having to turn at the same time, and so it happens during most slow manoeuvres. I tried driving in a circle, and from the outside, one can see the wheels juddering.

Any ideas what can be causing this? It seems to be probably connected to the differential.

Any help and suggestions would be appreciated.

[Fullmel]

Make sure one of your rear tyres are at the correct presser.
If they are ok there is a modified diff oil to help lubricate the limited slip diff plates this should cure your problem.

[thomr]

Yes, the tyres are at the correct pressures. I also bought new tyres for the rear as they were getting to the end of their lives, but that made no difference.

[wezzer-45's]

You will find hat the juddering is caused by the LSD.
They are sometimes very tight and cause a wheel to skip and a graunching noise when pulling off on lock or turning slowly.
Pop into your dealer and there is a diff additive that will cure this problem instantly for you.

[craig e]

hello
mine does this too, looked in past service and theres a charge for "kendall additive" its an oil additive for LSD units.
ive put these types of additives in jeeps wranglers that felt and sounded like the back axle was about to eat itself and hey presto a squirt of this stuff and perfect!!!!.
mines due for service soon will ask AM dealer to put some more in.
bet thats all yours needs

[thomr]

Many thanks for your replies. I will speak to my dealer about the additives suggested. Is it easy to add the additive?

[Swiss_Toni]

IMHO, you want it do this, as a good tight diff (hence the slight juddering) as it aids traction and influances the handling.

Additives usally make it slip more which is not the point in this type of car.

That said I don't know how old the car is but you may want the dealer to check the fluid level (if new) or if older you may want to have the fluid changed if it's not been done recently.

[thomr]

I spoke to my AM Dealer, and they had not heard of the Kendall LSD additive.

Does anyone know where to get the Kendall Additive from?

Is there any other alternative additive that would be suitable for an AM?

[blackice1]

Jaguar use the same additive .

[thomr]

I got my dealer to change the diff oil.

We used Shell Spirax ASX 75W-90, which is what Aston Martin now recommend, and it already includes an additive similar to the Kendall one.

Fantastic. The juddering has completely disappeared.

Many thanks for all your help on this topic.