Are Rear Diff ratios different -A4 auto vs S4 manual

[mrw]

Does anyone know what the rear diff ratios are in a 2009 avant 2.0 auto and a 2012 S4 Manual are? I need to know if the rear diff from the 2009 2.0 would work in the 2012 S4. I have found info on the B5, B6 and B7 but none on the B8. Thanks

[blbroo]

I would suggest that you get the part number and check it on a site similar to this:

http://www.jimellisaudiparts.com/pro...wd=&origin=pla

If you are replacing the diff in an S4, I would go with the S4 sport diff for better handling.

[bermudakid]

No they are not the same... ( I'll be back to insert my facepalm meme here <---)

A4 gear Ratios, 6 speed automatic w/Tiptronic (2009-2012)
1st4.171
2nd2.340
3rd1.521
4th1.143
5th0.867
6th0.691
Reverse3.403
Final drive 3.517

S4 Gear ratios

Manual:
1st: 3.667
2nd: 2.158
3rd: 1.52
4th: 1.133
5th: 0.919
6th: 0.778
Final: 3.68

S-Tronic:
1st: 3.69
2nd: 2.24
3rd: 1.56
4th: 1.18
5th: 0.92
6th: 0.75
7th: 0.62
Final: 3.88

Final drive has to be the same for the rear dif

[dscline]

No they are not the same... ( I'll be back to insert my facepalm meme here <---)

...

Final drive has to be the same for the rear dif

Just because the final drive ratio is different, doesn't mean the rear differential is different. ( I'll be back to insert my facepalm meme here <---)

If they change the rear differential ratio with every combination of car/transmission, that means they'd have to also change the front differential ratio. It would be much simpler to keep those parts universal, and change the ratios at or before the center differential.

I don't know the answer to the question, but knowing the final drive ratio doesn't necessarily lead you to the answer.

[Bordom]

Usually A4 auto and all S4 models have the same diff ratios. (B5 knowledge here, i may be missing things)

Everything graciously mispelled by Android

[wrxkyle]

does anyone know if the rear diffs are the same between auto s4's and auto a4's, even though the final drive differs?

[Smac770]

Not sure what you mean by "are they the same though they are different". Same class, like 0BC?

S4 with 0B5 DSG7 used normal diff 0BC code JKS with a 35:9 ratio or sport diff 0BF code (lots) with a 35:9 ratio.
A4 with 0B6 ZF6 used normal diff 0BD code KBU with a 43:13 ratio
A4 with 0BK ZF8 used normal diff 0BD code KBU with a 43:13 ratio or normal diff 0BC code KRR with a 43:13 ratio (KRR shows in ETKA, though the repair manual doesn't show a KRR allocation; the only 43:13 in it is KCC, but it has a different driveshaft flange diameter)

0BF is the sport diff. 0BE is a stronger version of the 0BF for the A8 with V8 TDI and 0BL ZF8 transmission.

No idea what's actually different about 0BC vs 0BD. I know I have a 0BD KBU with my 0B6 KXT in my '09 A4 2.0T.