ZF LSD Rebuilders? & questions...

cstreit · cstreit's Garage

I have a ZF LSD that used to be in my 915 race-tranny but pulled it out when I suspected it was worn. Because time was short, we were in the middle of the season, I replaced it with my spare Quaiffe dif. "temporarily".

I have the trans out for other issues and thought now might be the time to address this. So a few questions for the collective mind.

1. I'm assuming that all things being equal, the two-place ZF's were the 40% lockup type correct?

2. The only way to convert this to an 80% would be to machine the ramps and add more clutch/friction plates?

3. Who does this?

4. Is a 40% ZF LSD still better than a Quaiife for wheel-to-wheel racing? I'm concerned about the time to get this done, 3 weeks untill our next event.

Thanks,

onboost · 05-01-2007, 01:21 PM

Check out Gary Fairbanks in CT.

Paul

DW SD · 05-01-2007, 03:05 PM

Check out WEVO. Hayden set up mine with new clutch disks at 80 / 80 w/ a low breakaway torque, so I could use it on the street and light duty track.

I think the locking on braking is a distinct advantage over
the QUAIFE.

Doug

zotman72 · 05-01-2007, 03:33 PM

Powerhaus II in Boulder can help you too.

rdane · rdane's Garage

No help other than to agree with Doug. The ability to trail brake is why I have a 80% ZF in my street car. Works wonders there just like it does on th track.

cstreit · cstreit's Garage

Thanks guys,

Well here's the deal. I got some great info from Paul@ Guard Transmission about what to shoot for... I then spoke to Hayden@Wevo who is doing some other nifty work for me, and we assessed that I did have an 80% lockup diff config already!

THEN, I spoke with Mike@Guard who was extraordinarily helpful (and friendly even with my 4th phone call) in helping me re-measure the entire plate-stack and determine the proper plates, etc.. to get my preload set right. I am getting some new static plates from Wevo and the friction plates from Guard.

So big thanks to WEVO and Guard for the great info and patience with my phone calls.

sfoster13 · 05-02-2007, 11:11 AM

Chris, did it turn out that you had the 4 plate earlier ZF? Was it a 4 plate adjusted to 80% or the GT that came at 80%? I just spoke with Paul and he recommended against playing with my 2 plate to try and get to 80%.

cstreit · cstreit's Garage

It was a standard 915 LSD that had been modified to be 80%. I assume the lockup will be more abrupt than one designed for it like the GT, but Paul's the expert there...