4Owners

Hi. I'm hopeful to gain insight from the forum as to my course of action. Here's a recap of events:

This week, I had my 2018 Q5 Premium Quattro into the dealer for a few issues:

1. Gateway Cover Recall.
2. 3G campaign
3. To diagnose a reported issue whereby at very low speeds and turn (either left or right) while under power, the rear end seems to be sending a significant judder. It's almost as if the rear wheels are intermittently under power. Other Quatto's owned have never experienced this. Further the loaner Q they gave me was free from this distraction.

The tech took care of 1 and 2, but for 3, they claim there are clutches in the differential that are not engaging properly and wanted $4,500 +tax to replace and retest.

My Q has 55k miles, and while being a nice ride has had other repairs (covered under warranty). Turbo replacement and the Entertainment MMI Module. Both would have been thousands out of pocket.

Now with the vehicle being out of warranty, it's up to me to fix on my own. I'm very capable and have no issue swapping out the diff. I see diff's on ebay from low mileage Q's priced affordably.

Just wanted to see if anyone else has experienced this?

383vett

If it was a GM car, you would just need to add a few ounces of limited slip additive to get rid of the chatter. What do you have to lose?

Sandroad

For that kind of money, I’d think a second opinion would be good. Got any decent indy shops in Pittsburgh?

superswiss

Yeah, the Q5 has quattro ultra, which is very different from the previous Torsen quattro. The rear differential has an integrated decoupler. It's a dog clutch that decouples the driveshaft when AWD is not needed. Sounds like yours is malfunctioning and the driveshaft isn't getting decoupled. It's a very new and more complicated system than the fully mechanical quattro before.

4Owners

Thanks all for your thoughts. I think I'll first try to drain and refill. Took a while to locate the fluid type, but found G060190A2. Will see what happens, if anything.

This condition is quite annoying.

4Owners

I tried to see if AMSOIL's additive was compatible and it's not.

Wires

In the past I had a Honda with a 6-speed manual that I put in Red Line manual fluid (my buddy with a GM swore by it, and all the reviews were stellar). Well, every shift as notchy after that. Apparently the OEM Honda oil has specific additives to ensure proper operation. Personally, I'd recommend staying with Audi oil since changing brands is one more variable you are going to change while trying to figure this out.

Do you have the sport differential, or just regular?

4Owners

Current plan is to drain and refill using the OE fluid. (ordered and should arrive in a couple days).

I don't have the Sport diff. Just the regular one.

Wires

Sounds like the best plan. Take note of the fluid coming out. If it's fully of particulates, it would be saying that the clutches are failing.

4Owners

Roger that. I'll inspect thoroughly and report my findings later this week.