okbarnett

the trans fluid is different and seperated from the diff fluid which is 90W

SharkSkin

Only if you're talking about automatic tranmission cars...

Realist D.

My car ('88S4 with option 220) has always "shuddered" when accelerating slowly from rest while turning sharply. This is only up to about 5 mph. I always equated this with how 4WD trucks shudder when parking while the 4WD system is engaged. It's because the driveshaft to the inside wheel is loading up and and releasing. If there was no cluthch system to release the tension that has loaded up you would hear the inside rear wheel slip and probaly feel it hop just like on a 4WD truck.

hupp

K2S,

I believe I experience a similar noise on my shark as well. A clicking type sound, similar to a bad CV joint, but not as noisy. From what I've been told, a shim wears in the transmission thus allowing a slight interferance with first and reverse. Some cars are a bit noiser than others and some tend to get worse over time. Mine has made the noise for many years without getting worse.

Not worth tearing down the transmission to fix.

mpesik

I have an LSD as well and only on slow left turns 15km< would I feel it! -Never heard it! At highway speeds I would hear some drone/whining . I replaced the pinion shafts -I did this when I had total trans. failure. No problems to date. P.I.T.A!

okbarnett

Some reason, I thought the car was automatic. But none the less, I dont think a different type of fluid is going to quiet it down. I think there is a definate problem you are hearing. Have you tried hoisting the car and running it and checking around the components for the noise?

Kolbjorn S

I have not hoisted it while running, but next time in the garage I will do so. But I doubt I will hear anything as the shutter only appears in low-speed turns. If some experience manual boxes and 220 as totally quiet and no shutter, yes something must be worn. I'll try and check it out.

Andy C

Before replacing any parts or performing any repairs, I'd throw in some limited slip friction modifier like Redline makes. The grind/shudder sounds like the clutch plates in the limited slip are gripping too much. Possibly something is slightly worn but on my '82 I got the exact same thing after I replaced the fluid. Adding just a little bit of the friction modifier fluid made the differential slippery enough to stop grabbing and chattering and the shift action wasn't really affected. It was kind of lousy before because of the standard worn synchro problem on early 928's and about the same after. So adding a little fluid solved the differential problem and didn't seem to affect anything else.

Actually the Redline does what it's supposed to. It says for optimal traction from the limited slip add their basic NS fluid and then add the friction modifier until the chatter stops.

Kolbjorn S

Can you add that friction modifier (Redline) on a manuel car where trans and differential share the oil? According to Brent 89 GT (page 1 of this tread) it seems to be valid for automatic only, and not recommended by Porsche? Thanks.

Andy C

Yes, I added the Redline to the manual on my car. I originally added a different fluid than specified, one with a higher friction coefficient to help the worn out synchros in the gearbox. The idea being that the extra slight bit of friction would help the worn out synchros engage each gear better. Since the two are connected the higher friction fluid helped the gearbox but made the clutch in the differential too "grabby" and resulted in chatter. Adding the friction modifier solved the problem.