Boeing 717

Hey guys im afraid my LSD is worn out. It still works fine but man is it ever noisy. What are my options?? Can i remove the old have it rebuilt and reinsert. Should i buy an aftermarket type?? What kind of cost can i expect??? I had one shop qoute me 1000-1500 dollars to rebuild it.

Are there any fluids i can put in my Tranny to quiet it up a little??

Thanks

Metal Guru

There will be the noise of the clutches slipping. It will be loudest when cornering off-throttle or when backing up while turning.
Mine was rebuilt by the PO to the tune of $4000. What makes it expensive is that the diff must be converted to the 3.6 clutches which are thicker as the 3.3 clutches are NLA.
Before you rebuild I would try changing lube. Try Mobil 1 LS 75W-90 as it has limited slip additive in it. Or use Mobil 1 Delvac 75W-90 and add GM limited slip additive.

One of Twenty

Jerry,

I'm not advocating this, but you could turn up the volume on your radio.

Boeing 717

Well i cant afford to do it right now anyhow....what are the ramifications of continuing to drive it??? I called one porsche "specialist" transmission shop and he told me to put in a Friction Modifier made by FORD. Do you think it would help some???

gr1275

Jerry,
Is this the trans noise you asked about a month or so ago? If it is in addition to, perhaps looking for a used transaxle assembly might be a reasonable solution. If this is the noise, I would consider either finding a rebuilt unit or R&R the existing unit and have it rebuilt.
FWIW,I have had some good results from synthetic lubes as well as using GM limited slip additive in existing fluid.

Gary

Ag02M5

I hate the chatter. It is embarassing to back up in public. Will replace at some point.

Boeing 717

Yes Gary it is, the porsche tranny guy i spoke to today said that all of the noise im hearing, the whining, chattering, clunking, are all symptons of a worn LSD. He said i can replace or have the LSD rebuilt; however, there is no need to rebuild the entire transmission if its shifting well. I am going to try this LSD additive, he swore by the stuff, but also warned me that it may quiet it a little but it was probably time to rebuild the LSD.

jeff91C2T

Hey Jerry,

Seems there is a lot of "conflicting" information we're getting on the LSD topic. Having just gone through this I can offer my experience;

- The LSD can have new plates installed (readily available). Does not require a trans over haul and is not difficult. The diff is pulled, new plates installed. This is the most straight forward solution as you do not have to re-shim for a new LSD.

- I was under the impression that mine needed replacing as well. After tearing it down they were fine. So take the advice "time to requild", with out testing it properly with a grain of salt. Case in point is the diff's made this noise when new. Can they really be bad with so few miles?!? BTW...mine had 90k and the plates still measured in spec.

If it were my car, I would first look at what type of fluid is being used and then put in Mobil 1's Delvac SHC 75w/90 (if not already). Also, $1.5k to rebuild an LSD might have a bit of the Porsche tax built in. I dropped off my box to be regeared, new syncro's installed, and LSD rebuilt for 10 hours of labor (charged).

Boeing 717

Hey Jeff thanks for the reply. Actually the guy i spoke to on the phone did mention just having the plates installed, im not sure if that was what was going to cost 1500 dollars. Where did you have your box redone?? What was the total cost to you???

Thanks

jeff91C2T

I'd have to go back and look at the receipt (which is burried in storage) so I'm going to guess at the final number. It was just over $3k...which included a new clutch, pressure plate, TB, syncro's and plates. His details are below;

19607 200th Ave NE
Woodinville, WA 98077
Attn: Leif Johnson
425-788-3476
ljohnson@autowerksnorthwest.com

I was able to drop the box off and "participate" in some of the tear down. Leif works for himself and has done quite a few of the G50's. He does club racing as well and has a few little tricks as he calls them to help with durability. Good guy and has a great reputation among the porsche crowd in the NorthWest.

Question for you....have you tried a hard acceleration while turning? If so do you spin the inside wheel or both?? If just the inside then then ya, the diff is showing signs of wear.

cobalt

It was my understanding that when they go they no longer make noise. If they are making noise they are working. I know of a 91 that had the LSD go on it and it made no noise whatsoever.

Might be worth a second opinion.

Metal Guru

Just checked the PET and it looks like the 3.3 and 3.6 share the same diff. Sounds like someone hosed the P.O. of my car pretty good on that rebuild.

cobalt

Ouch,

Yes all 964 turbos used the same 20/100 LSD which used the thicker plates than the 40% units used in the C2's.

jeff91C2T

Hey Anthony...actually the C2T's could get the 40/100 as an option over the 20/100 standard (mine had it).

cobalt

They didn't offer a 40/100 it was either the 20/100 or the 40/40. Yours might have been converted. i have all the option and ordering forms for these years and the only option code is 220. It was used to order the 20/100 for the turbo which was actually standard on the 92-94's even though the option is listed or the 40% for the C2's. IIRC the early cup cars had the option of either.