[urq] Final drive

[Steve Eiche]

Yes, ALL 4kq's had 4.11 final drive, and ALL ur quattros had 3.89 final drive, including the 20V.  The '84 4kq's had one piece rear diffs.  In '85 they went to the rear diff with the bolt-on mounts on the 4kq.  The early ones had the large flanges like the ur quattro, the later cars went to the small flanges.  So, if you want to convert an ur quattro to 4:ll, you want the '84 4kq rear diff if you are staying with the early suspension/subframe.  The '84 4kq is also the best rear suspension/subframe donor if you want the late suspension with a one piece rear diff (stock ur quattro).  The early '85 4kq is the best donor if you are converting to late rear suspension and 4.11 final drive, as you can still get the flange seals for the rear diff with the bolt-on mounts.  You want the big flange rear diff as then you can use the ur quattro axles.

Only the MB and RR ur quattros used the rear diff (code ALZ) with the bolt-on mounts and they were the only small chassis (B chassis) rear diffs with a 3.89 final drive.  All the earlier ur quattros used the one piece housings.  FWIW, the RR that I got my rear suspension and diff from also had the late rear subframe and tie rods that were used on the late CQ's and S2's.  That appears to be a late '90+ thing.

Steve

Nate wrote:

All 4kq are 4.11:1.  The style of the housing changed mid-1985 model year
going from a one piece unit with cast-on mounting arms to a three (or more)
piece unit with bolted on mounting arms.

The axle flanges changed mid-1985, too: earlier axle flanges fit UrQ axles,
but the later ones are too small and need to be changed if the diff is to be
fitted to an UrQ.

Nathan Engelbert
83 UrQ DA900453 (with 4.11:1 final drive 200q20v trans and 84 4kq rear diff)
95 S6 avant

On Mon, May 23, 2011 at 6:48 AM, Mike Sylvester<mike at urq20v.com>  wrote:


> >  I thought it was the opposite.
> >  The '84 might have 3.89.
> >
> >  I know for sure the later models(85+) had 4.11.
> >  That is what I used when I converted my urq to use the 200q20v
> >  transmission.
> >
> >  Mike