Replacement rear Diff: Standard or Quaife

[niall1]

Hi Guys

I need to replace my rear diff as after 60k miles it has too much play for my liking. Took it off and had a look to make sure as it was clonking like mad. The noise was partially rear driveshaft play (replacements on order since May from BMW Germany with ETA of August.. ) but mostly sloppy movement within the diff. I've been looking into my replacement options as the OEM if f'in expensive and Quaife appear to offer an 'uprated' solution:
https://shop.quaife.co.uk/quaife-bmw...g-m3-cs-m3-csl

I use the car as my daily (fast B road equivalent) and the occasional track day. It doesn't get spared and I enjoy a bit of cornering 'movement' on my daily drive home..

Has anyone fitted the Quaife Diff and have any insight as to whether it's an improvement on OEM?

Thanks
Niall

[_Nathan_]

Put a drexler in, traction is brilliant. If not I would just refresh OEM diff.

Quaifes go open when one wheel off the ground (so all power goes to the unloaded wheel), unless they've changed the design?

[cslsuperfan]

Had this debate with Bart's and Simpson's.

Horses for courses but I elected for oem as it's been A1 for 60K miles.

That said I've heard a lot of good things said for the aftermarket options.

[niall1]

Thanks for the replies guys. The indy I use is looking for part numbers to replace the internals if that's an option. The problem in the Emerald Isle is a lack of expertise that you have readily available in the UK. I'll look into the Drexler. I didn't know that about the Quaife and it is a serious factor to consider as the roads are so choppy here that the inside wheel on a bend would often have a little air time..

[JBird]

Originally Posted by _Nathan_

Put a drexler in, traction is brilliant. If not I would just refresh OEM diff.

Quaifes go open when one wheel off the ground (so all power goes to the unloaded wheel), unless they've changed the design?

What is involved in "refreshing" and OEM diff, i.e., parts, labour etc.

[_Nathan_]

Originally Posted by JBird

What is involved in "refreshing" and OEM diff, i.e., parts, labour etc.

Not sure to be honest, never looked in to it - probably just buy a new one.

I really rate my Drexler (not that I can remember driving my car ), traction was on another level and so predictable when it went compared to the OEM diff.

[billyboysm3]

I put a 4.1 in my M3 diff. Totally transforms the car.

Think it was £800 for CWP and about £400 to fit with new seals and some other bits.

[_Nathan_]

Different thing - final drive can be done in conjunction with Drexler too - I think 3.9 probably the sweet spot for a road car that is also used on track.

[Mike R]

Putting 18s (with 265/30 rear tyre) on nearly has the same effect as putting a 3.9 ratio in the diff .

19s standard final drive Max speed at 8000rpm
Diff Ratio 3.62 N/A
1st Gear Ratio 4.23 = 39.26mph
2nd Gear Ratio 2.53 = 65.64mph
3rd Gear Ratio 1.67 = 99.44mph
4th Gear Ratio 1.23 = 135.02mph
5th Gear Ratio 1.00 = 166.07mph
6th Gear Ratio 0.83 = 200.09mph

18s standard final drive
Diff Ratio 3.62 N/A
1st Gear Ratio 4.23 = 37.71mph
2nd Gear Ratio 2.53 = 63.04mph
3rd Gear Ratio 1.67 = 95.51mph
4th Gear Ratio 1.23 = 129.67mph
5th Gear Ratio 1.00 = 159.50mph
6th Gear Ratio 0.83 = 192.17mph

19s and shorter final drive
Diff Ratio 3.90 N/A
1st Gear Ratio 4.23 = 36.44mph
2nd Gear Ratio 2.53 = 60.93mph
3rd Gear Ratio 1.67 = 92.31mph
4th Gear Ratio 1.23 = 125.32mph
5th Gear Ratio 1.00 = 154.15mph
6th Gear Ratio 0.83 = 185.72mph

18s and shorter final drive
Diff Ratio 3.90 N/A
1st Gear Ratio 4.23 = 35.00mph
2nd Gear Ratio 2.53 = 58.52mph
3rd Gear Ratio 1.67 = 88.65mph
4th Gear Ratio 1.23 = 120.36mph
5th Gear Ratio 1.00 = 148.05mph
6th Gear Ratio 0.83 = 178.37mph

And for Billy and Adem:
18s with even shorter final drive
Diff Ratio 4.10 N/A
1st Gear Ratio 4.23 = 33.29mph
2nd Gear Ratio 2.53 = 55.66mph
3rd Gear Ratio 1.67 = 84.33mph
4th Gear Ratio 1.23 = 114.49mph
5th Gear Ratio 1.00 = 140.83mph
6th Gear Ratio 0.83 = 169.67mph

[B0rJarZz M.]

Originally Posted by Mike R

Putting 18s (with 265/30 rear tyre) on nearly has the same effect as putting a 3.9 ratio in the diff .

19s standard final drive Max speed at 8000rpm
Diff Ratio 3.62 N/A
1st Gear Ratio 4.23 = 39.26mph
2nd Gear Ratio 2.53 = 65.64mph
3rd Gear Ratio 1.67 = 99.44mph
4th Gear Ratio 1.23 = 135.02mph
5th Gear Ratio 1.00 = 166.07mph
6th Gear Ratio 0.83 = 200.09mph

18s standard final drive
Diff Ratio 3.62 N/A
1st Gear Ratio 4.23 = 37.71mph
2nd Gear Ratio 2.53 = 63.04mph
3rd Gear Ratio 1.67 = 95.51mph
4th Gear Ratio 1.23 = 129.67mph
5th Gear Ratio 1.00 = 159.50mph
6th Gear Ratio 0.83 = 192.17mph

19s and shorter final drive
Diff Ratio 3.90 N/A
1st Gear Ratio 4.23 = 36.44mph
2nd Gear Ratio 2.53 = 60.93mph
3rd Gear Ratio 1.67 = 92.31mph
4th Gear Ratio 1.23 = 125.32mph
5th Gear Ratio 1.00 = 154.15mph
6th Gear Ratio 0.83 = 185.72mph

18s and shorter final drive
Diff Ratio 3.90 N/A
1st Gear Ratio 4.23 = 35.00mph
2nd Gear Ratio 2.53 = 58.52mph
3rd Gear Ratio 1.67 = 88.65mph
4th Gear Ratio 1.23 = 120.36mph
5th Gear Ratio 1.00 = 148.05mph
6th Gear Ratio 0.83 = 178.37mph

And for Billy and Adem:
18s with even shorter final drive
Diff Ratio 4.10 N/A
1st Gear Ratio 4.23 = 33.29mph
2nd Gear Ratio 2.53 = 55.66mph
3rd Gear Ratio 1.67 = 84.33mph
4th Gear Ratio 1.23 = 114.49mph
5th Gear Ratio 1.00 = 140.83mph
6th Gear Ratio 0.83 = 169.67mph

4.10 with 18s is perfect if you have your engine modified (better valves, springs, pistons, rods, etc) with the rev max around 8.5K