North Coast Cab

Finally got the 993 on the track for some hard duty on a tight course, Grattan Raceway. Rear wheel spin like crazy on 3 or 4 turns. Is the factory LSD worthless or is it just worn out? What can I do on a rebuild to improve it without spending $2k on a new one?

TIA, John

samsnead

No personal experience, but when I was buying my car nearly every car I saw with LSD it needed replacement.

Steve Weiner-Rennsport Systems

John,

In a nutshell; yes & both.

The fix is:

1) Least expensive: simply replace the plates and tighten the pre-load as much as possible

2) More expensive: install the Guard plate kit

3) Best solution: install the FAR superior Guard LSD

993Brendan

I just got my factory diff rebuilt by Guard and it arrived on my doorstep this evening. Can't wait to try it out!

993Porsche

Dumb question, I know, but someone's got to ask it. How do you know if you have a LSD installed?


Ken

TheOtherEric

You know you're an LSD owner if:
- You own a C4
- You own a C4S
- Your options sticker on the underside of the hood lists the code for it.

I had my LSD friction surfaces replaced by Guard and I've been happy with it.

AX993

Another duma$$ question. I have been informed (here on list) that an experienced tech needs to install a Guard LSD, BUT if I just get Gaurd to rebuild my stock LSD, can I reinstall it by my(duma$$)self or does it still take a qualified tech to do it properly ??

chris walrod

You can R&R your diff without having to reset backlash and bearing preload as long as you reinstall the diff that came out of it and you are not changing your carrier bearings. Having the internals rebuilt is fine for street use.

TomF

I have the LSD option on my car and I love it. I have driven 993s with and without. The LSD really adds to the 911 experience IMHO.

AX993

Thanks for that info Chris !

Kika

how does one know if the LSD is worn out, and or needs replacing? Both of my 911s had it, so I have never driven a 911 without LSD.
What are the symptoms/repercussions of driving with a worn/bad LSD?

Analog Theory

Next time your rear is in the air have someone hold one rear wheel while you turn the other. If the one your're turning locks up, your LSD is working. If it spins....then your factory unit is shot (which most are a couple years from new at best anyway). There's also a parking lot donut maneuver that will tell you but this is safer.

Smiles

Are C4's and C4S's LSDs fail later than C2 and C2S cars because of the drive line (and associated things like EBD)?