Quote:
Originally Posted by Marc Bixen
As usual there are many different thoughts and theories.
1) always check the basics. as stated clutch adj, shift bushings, trans and motor mounts etc.
2) as usual John Walker is spot on with measuring the assembled syncro and slider, unfortunately this can only be done when the trans is disassembled. We've returned a number of these parts that where out of spec. Many of these parts are no longer available from Porsche and must come from the aftermarket. In general this will effect only certain gears, those repaired. Typical repair is 1st and 2nd on a low milage car like yours.
3) This can also be a Clutch pilot bearing issue. If the trans input shaft isn't turning freely it will cause hard and or notchey shifting.
4) If it has synthetic trans oil in it GET RID OF IT. 901's and 915's don't like synthetic. We use ONLY Kendall 80-90 and if you have a limited slip Kendall LSA additive
5) Apples to Apples, are the other cars your driving equipped with the short shift kit? There is also an adjustment, pinch bolt on the shift tower that if over tightened makes it difficult to move left and right. Is the shift tower properly lubricated?
6) and last, are there aftermarket parts in the shift linkage. Many times we've seen "rebuilt" shift couplers with poly or bronze bushings that don't have sufficient play in them. O.E. couplers are not "tight" they have some play.
Marc Bixen
Red Line Service
Porsche Parts & Accessories | **************.com |
Thanks everybody -- especially Marc and John.
I know that the trans rebuild included synchronizer rings for gears 1 thru 4, and new dog teeth for gears 1 and 2. No sliders were replaced from what I can make of the parts list. Flywheel was resurfaced and Sachs clutch kit was installed at the same time. I don't see a clutch pilot bearing on the parts list, so that's a possibility.
I see that a new ball cup bushing was put in when the new factory short shift kit was installed (replacing the factory short shift kit that the car originally came with). I don't see any evidence of a new shift rod bushing or any other new shift linkage parts, so I think I'll throw in a complete bushing kit and adjust the clutch cable and pedal. I prefer this to the more drastic options, such as a $700 Wevo shifter.
All of these repairs were done ~5,000 miles ago (along with engine top-end).
I definitely plan to dump the trans oil and replace with Kendall. I have a quick question about the Kendall...
Should I get the
NS-MP Hypoid Gear Lubricant in the 80W-90 weight and add the
Limited-Slip Axle Additive Concentrate to it? If so, how much of the LSD additive should I add?
...or...
Should I get the
Special Limited-Slip Gear Lubricant, which has the LSD additive already in it? I'm not certain if this starts from the same base oil as the NS-MP or not, or what the additive ratio would be.
Thanks!