DB9 Grinding/struttering

[nick1867]

Hi, New to this so hopefully posting in the right place.
I have an issue with the car and wanted to get some advice.
I bought my first Aston in March this year, a 2007 DB9. All was good until July when i had a gear box fault and the car was stuck in 4th. This resulted in the garage having to rebuild the gearbox and install a new part from ZF.
Since i got the car back it seemed to grind/stutter when setting off turning. I took the car back to the garage and they said that after speaking to AM directly they needed to add a solution to the diff. It seemed ok after this for the first couple of days but now seems to be getting worse. I can see from the initial invoice from the gearbox that they added 3 litres of diff fluid at this time.

Not knowing much about engines im concerned that driving will make it worse. I'm also apprehensive to return to the same garage.
My brother in law is a mechanic and said he wants to replace the Diff oil as he believes they may have not done it correctly. If so can anyone recommend the best oil and 'added solutions' to purchase.

Any help on this would be greatly apprechiated.

Thanks
Nick

[Neil1300r]

Was it an AM or AM specialist garage?

[paulrog1]

Sorry your having problems.

You need 1.6 litres of diff oil - https://astonmartinbits.com/models/4-DB9/parts/674

Also you need to put in the oil additive it's called Kendall - https://astonmartinbits.com/models/1-DB7/parts/356...

This is the proper stuff for the rear diff, when you do it make sure the car is level, drain the diff first using the drain plug, remove the plastic filter and either clean that with white spirit or replace it, then after putting the filter back in, put the additive in first then fill the diff up until the oil gets to the fill plug level. you also need to replace the rubber o-ring for the plastic filter and 2 copper washers for the fill and empty plugs.
You need to remove a plastic rear undertray first held on by 9 small torx screws

A great blog site about DB9 service jobs - https://aston1936.com/2016/01/03/draining-the-rear...

I hope this helps.

Edited by paulrog1 on Wednesday 12th October 21:48

[Cerberaherts]

I'd have the oil changed for a proper GL5, such as valvoline 75w90 rather than the O.E GL 4/5 and a Kendal friction modifyer then stick a couple of hundred miles on it and see how it is....

[nick1867]

Thanks, i'll order the bits now and see how it goes.
Hopefully fingers crossed it sorts it.

Thanks for your help