Spidey 993

I took my car in today to get the starter replaced. It was having intermittent firing issues, infrequent so I figured I would be proactive.

Anyway, I got her up on the lift and notice only one rear wheel is turning at a time. (Car was converted to 2WD).
Mechanic determined the clutch pack was worn out and I need a new differential. He contacted Guards Transmission to figure out a action plan.

Just curious if anyone else had this happen in recent memory and what did you do in your particular case? MarkD recommended I use GT, I understand they do exceptional work. I was unaware these have a life span of ~30k miles or so.

bb993tt

I destroyed the LSD that came with blackie in one season at MMC in 2WD mode. I "believe" it was a PMS unit. Don't know how many miles it had on it, but the entire car had less than 30,000 when I got it. MMC has quite a few low speed turns, which can be hard on these pieces with a relatively high HP motor when you're going to WOT coming out of all of them every lap. I could certainly light up the tires tracking out when it was going away. Replaced it with a Guard unit.

Felix

From memory transmission removal is not required; the diff can be removed from the side of the transmission while still in place.

DM993tt

Replace with Guard

Texas993

Tony, I need to do the same thing. Guard sent me the instructions and it seems like a fairly easy DIY. No engine/trans drop required.

While Guard didn't quote me a price for rebuild, my guess is <$1000.

I did the wheel spin test recently on a lift. When I turned one front wheel, all four wheels turned. That is good!

Spidey 993

Patrick, hmmm interesting. I will contact them to see those instructions unless you can send to me.

Edit: Looking into this further, looks like they are recommending a new Torque Biasing Differential. I have a call into Mat to find out more.

Thanks!

Spidey 993

I talked to Mat at Guards Transmission and he explained some scenarios bringing my differential back to spec or if I were to track this car. Also since my car is 2WD plays a factor into it, reduces cost actually since I don't need a 4 clutch diff.

He has me reading a thread showing a RL in CA replacing his on a 997, if I wanted an idea on DIY.
Not sure if that's something I want to tackle, but I find it very interesting and makes me want a lift even more.
https://rennlist.com/forums/showthre...ferrerid=97793

Anyhoo, I feel better thanks to Mat (GTgears) and another learning opportunity.

Texas993

You have the same link/DIY that Matt sent me. Looks pretty easy.

Glad you figured it out. And I don't see any need to run out and get it done immediately.

JJayB

I had heard the prior owner was in prison most of the time he owned the car and hardly exceed the speed limit when he was out due to possible parol violations.
You might want to check the door panels though.

bb993tt

^^ LOL

Door panels appear to be in very good shape, JtF.