stevewashburn

My LSD is gone and I need to make a decision on replacing it. I am reluctant to replace it with the stock LSD because it will just go again in the future. I was wondering if anyone has replaced the stock LSD with a GT3 Cup LSD as discussed previously here. If so, what was your experience with the install, cost and performance?

Shock Doctor
'04 GT3 blk/blk

roberga

there is a great guy "Monty" at Redmond European. Redmond, Washington. Give him a call.

guykoken

Shock Doctor:

What symptoms/tests have lead to your concluding that your LSD is kaput?

Richard Bain

PogueMoHone

Richard,

What ever happened to the class action lawsuit you were initiating?

viperbob

Consider a Guard limited slip. I have installed a number of them (and had one myself). They are bullet proof, and are available in different configs of accel/decel lockup. Many of the race teams use Guard products. When you get it though, it is hard to actually put inside your tranny and not put it on the mantle over the fireplace. They are really works of art...

DCLee

El-Cheapo option #2--

Get Guard to redo your stock LSD with his internals for a real 60/40 split-- the factory diff feels very weak and has nowhere near the bite you expect.

Lee in D.C.
'04 RS clone

stevewashburn

Viperbob, thanks for the info on Guard. Sounds like the way to go. I'm sensing this is not an inexpensive project. Any rough ideas on cost?

Richard, regarding symptoms, it was very hard to lay down the power coming out of corners and there was more oversteer to manage than there should be. I would be flying through the high speed sweepers and than losing ground in the tighter parts of the track (please no comments about driving style -this isn't the problem). Also, when the car was new, I would have the transmission LSD noise when turning sharply. There is no noise any more.

ShockDoctor

guykoken

Colm: Here was my reply to the same question, which you posted on November 19, 2005 in bam's "selling ceramic brakes" thread.

I could not interest a lawyer in taking on the case. None of them were interested in acting for an hourly charge, and thought the cases weren't potentialy rich enough to support a contingent fee arrangement since, they thought, their chances of obtaining a jury award for punative damages was poor, due to the supposed affluence of the plaintiffs. Then, to compound the difficulty, several potential plaintiffs dropped out, once they learned that it was going to cost them money to prosecute the action. In the end, I had about eight plaintiffs left. I figured at least two of those would opt out when it was time to write a cheque, so I gave up my search for a lawyer. It ended with a whimper, not a bang.
Richard.

viperbob

ShockDoctor - This is not a cheap upgrade. The unit sells for $2200 IIRC the last time I bought one (might be $2000). They are also kind of a pain to setup. Takes anywhere from 5-10+ hours at most shops. It is trial and error to get the proper amount of shims, and then getting the proper backlash. No two diffs are the same and it makes a difference.

I cheated at my last shop. A precision machine shop next door (lots of multi axis CNC machines that built parts for nuclear reactors) would measure (out to 4 decimal places) the overall height of the diff, bearing surfaces, and ring gear surface of the old and new parts. Then it was easy to get the proper shims installed the first time. It made the job so that it was a 3-5 hour process for me. The guy next door had a 962, so he loved to see all the Porsche parts...

Larry Herman

Bob, if you send Paul Guard your LSD, wouldn't it go right back in place? Would something change relative to the R&P on re-assembly?

viperbob

Larry, I am sure Paul can do anything, but I am not sure it would be practical. You are talking about a custom one off diff made to you specs. If he would do it, I am sure the time to set it up and build would offset any reduction in shop time.

Also, no shop is going to pull a diff and have a car disabled on a lift for the time it would take to send off and get the new one back. So now you are down to DIY. You still need remove the races from the case and cover and install the new bearings. Then reassemble using a dial indicator to check that back lash according to the manual. Just machining tolerances of the bearings and races and shims can throw off just a bolt in reinstall. It is still possible that a very small amount of shiming may still be needed even if you were just reinstalling the same diff.

Larry Herman

Gotcha.

Phokaioglaukos

Brian Copans will send you a box that holds the whole transmission for transport to his shop. Shipping is not so very much from the NE US. If you full the dif he will also fit the Motorsports parts to it, and he assumes that the backlash doesn't change. He doesn't report any issues with that assumption, but shipping the whole transmission may be wiser. Brian says that if you remove the oil cooler the transmission is compact to ship.

Fastest928

When I put Pauls LSD in Viperbobs 993, it took me about 6 hours with the trans in the car. It was done with great difficulty and are, but the backlash was nailed!

Anyperson can rebuild a factory lsd in about 2 hours ... all you need are the corrrect fricition plates, which are wear items anyways.

pedsurg

I think it's the driving style : )
Jack