the1weezle

Last month I bought a used q7, and took it to the dealer, and it passed all of their safety inspections here in Japan.

I noticed 2 strange things after swapping in new oils/brakes/coolant/ PS fluid....

1. I still get a gear whirring noise that I didnt have on my old A6. I am thinking differential or transmission... should I change the fluids for these? Could it be something else? Am I worried over nothing?
2. My driver's side rear suspension leaks out overnight sometimes. Some days I can go to work and its still just as high, and sometimes It looks like the lowered for loading level. This has never noticeable during a workday (7hrs). I think it has something to do with our really cold nights (15C different between night and day here).

Regards,
A new q7 owner

Dudeness30

I would check/ change fluids in both differentials and the transfer case as these are easy, then the transmission too.

dreadlocks

Could have a stuck check valve on Air bags, they get particularly sticky when its cold.. moisture from the air can cause em to freeze and get stuck.

the1weezle

I have no idea how to change/which is the right fluid for my transmission. I would rather let a specialist do that.
I didnt even think about the transfer case... is there a guide for our vehicles?

I live and bought this car from a tropical climate... the previous owner never drove it off this island, I am not so worried about frozen parts. Its likely never seen temps below 40F(5C)

the1weezle

I didnt even think of the transfer case.
Any idea on which oils I should use for the diff and transfer case.
My plan was to use a 75w90 for both differentials...


I dont think anything is frozen. Its pretty warm here.. about 25C(80F).

Built4Sin

https://www.audiworld.com/forums/q7-...hange-2969607/

the1weezle

How can I find the part number for my vehicle (4.2) because that guy posted for a Diesel. I am pretty sure that the transmissions for our two cars are different, which might affect the transfer case, but I want to be sure.

dreadlocks

its the same oil regardless, if you dont believe us walk up to your dealer service dept and order it from them w/your VIN.. FYI Transmissions are same manufacturer, just different gearing.. and this is diff/transfer oil, not transmission fluid

the1weezle

Oh sorry I thought transfer cases usually match transmission fluid.

I knew the diff oil is closer to MT fluid than atf.

I tried to find the parts... but my local amazon doesnt sell it.. nor does my dealer, who I just called.
It will cost me about $100 per bottle for the audi genuine stuff. What are some good alternatives?

Dudeness30

The Audi fluid is around $26 a bottle. If you buy it online ECS is a good choice, but the dealer should be around the same price.