Rear diff ratio?

[shone190]

Hi guys,

I got one brand new rear diff but I don't know what gear ratio is. Part number is v 857 525 053 f and I see in Etka that it's from several Audi models:



I know that URguattro diff ratio is 3.89 but other old quattro models (Coupe, 80, 90) are 4.11.

Is there a chance to find out what gear ratio is this differential?

Thanks a lot in advance.

[s2_wot]

it will have a 3 letter code stamped into it. Possibly on the underside. The code will reveal all.

[shone190]

There is code KFL on it.

[mcandmar]

Mark a line on all the flanges, then rotate both output flanges 10 times while counting the number of rotations on the input flange, then divide that number by 10 = final drive ratio.

[shone190]

Great, I'll try it ASAP

[shone190]

I don't believe, it's 3.89 ratio, brand new URquattro rear differential

[UrS4boy]

I don't believe, it's 3.89 ratio, brand new URquattro rear differential

857525053 (no F) shows up as a 1983 A80Q rear diff, 37/9 = 4.11. DO the recommended count to confirm one way or the other.

[shone190]

I just do that, actually, my friend did because diff is at his place. He said that he turned 39 times input flange and output flanges turned 10 times. That's 3.89 as I understood?!?!

[UrS4boy]

I just do that, actually, my friend did because diff is at his place. He said that he turned 39 times input flange and output flanges turned 10 times. That's 3.89 as I understood?!?!

If that is true then the diff is not compatible with the 01E DGU 6 spd you are hoping to install.

[shone190]

I bought today rear diff with 4.11 ratio, so that problem is solved