DRC Failure symptoms - sagging?

[MFT]

Well, took the Audi into the dealer today, and they couldn't find anything. They apparently inspected everything possible and checked DRC pressures and everything checked out.

So, not sure what to do next. Maybe the LR spring is fatigued and just sagging? Thinking about getting them to just replace both rear springs and see if that will fix it. But, in this scenario, I assume they would have to de-pressurize the DRC and then re-pressurize it again, which is may be inviting trouble since it seems to be working OK now.

[RS4pete]

The rear springs are housed about 30cm in-front of the rear shocks and can therefore easily be removed without the need to de-pressurise the DRC. You'll probably need to unbolt the shock from the wishbone but that should be it. Its the fronts that can sometimes require the DRC to be de-pressurised to fit springs, although a few Indy's can still fit front springs without de-pressurisation.

If you know a good independent (and are 100% sure it is lower on one side) i'd get them to swap the springs over with each other. That way you can confirm if it is or isn't that springs causing the issue. It'll also allow a good inspection of springs themselves and the spring mounts.

However, I'd be very surprised if the spring had fatigued. Do you know any history of the car?

[MFT]

The rear springs are housed about 30cm in-front of the rear shocks and can therefore easily be removed without the need to de-pressurise the DRC. You'll probably need to unbolt the shock from the wishbone but that should be it. Its the fronts that can sometimes require the DRC to be de-pressurised to fit springs, although a few Indy's can still fit front springs without de-pressurisation.

If you know a good independent (and are 100% sure it is lower on one side) i'd get them to swap the springs over with each other. That way you can confirm if it is or isn't that springs causing the issue. It'll also allow a good inspection of springs themselves and the spring mounts.

However, I'd be very surprised if the spring had fatigued. Do you know any history of the car?

From what I was able to found out from the dealer I bought the car from, it had previously been in a "minor accident" (rear ending), though this was apparently quite some time ago. I bought the car in December 2012 and I only noticed the difference in ride height about a month ago, so it seems like a more recent issue.

Perhaps getting an alignment check would be a good idea as well?

[PetrolDave]

it had previously been in a "minor accident" (rear ending)

Perhaps getting an alignment check would be a good idea as well?

Definitely worth it IMHO.

[MFT]

Well, Audi checked out the car and they could not find anything amiss. According to Audi Canada technical services, there are no specs for ride height for the RS4 (questionable?) so their guess is that it's just wear. Next option - swap out the springs Left to Right? Alignment?

[MikeFish]

Or a set of H&R lowering springs.