Formula94lt1

My splines looke like triangles now instead of plateaus. I was curious what causes this at one end and not the other.

Mrmerlin

usually a loose pinch bolt and water corroding the splines.
Usually the rear pinch bolts are not tight.
I dont know know why but just about every one i check is not even halfway close to tight

Formula94lt1

Great info, thanks. I saw there was some anti-seize of sorts on the splines, was this from the factory you think or no? Sean Ratts said to install it dry, should I clean it off?

Mrmerlin

I would put some hi temp grease on the splines so they dont rust ,antiseize would also work

Black Sea RD

Just adding to what Stan is saying, a light coating of anti-seize is a good idea for the drive shaft splines into the couplers both front and rear, except for into the front flex plate clamp of 928 automatics. Prevents later corrosion and possible failure of the drive shaft within the couplers.

One problem for loosely tightened pinch bolts at both the front and rear couplers of the drive shaft, to include the front clamp pinch bolt of automatics, is that many home mechanics, and even pro techs, do not use a torque wrench to properly tighten the pinch bolts. Anyone who has used a torque wrench to tighten the pinch bolts to the prescribed 59 ft lbs. is usually surprised how tight that figure really is. We use a long handle torque wrench for extra leverage since using a short handle medium sized torque wrench makes it a bit more difficult to tighten them properly.

HTH,

Jim Chambers

I think Constantine answered my search question, but to be sure:

59 lbs on both pinch bolts on the front sleeve (5 spd) and 59 also on the rear clamp?
I checked both the WSM and Spec Book for my car and it is not clear that 59 is correct for all 3 bolts.

Rob Edwards

59 ft lbs on all 3. 8mm socket head cap screw, grade 12.9. Green.

Mrmerlin

I use the 66ft/lbs prescribed by the TSB Porsche issued, also blue loctite on the pinch bolt threads
IIRC the TSB recommended to increase the torque of the bolts by 10% so 10% of 59/ 60 is 6 ft/lbs

ROG100

IIRC the TSB also recommends replacing the bolts as well.

Mrmerlin

Roger, yes thats correct thanks for mentioning it,
its even more of a critical must do,
if after removing the bolt the shanks are damaged.
as the bolt can fail and then?????

jeff spahn

And then you have a bad day when the bolt fails

Jim Chambers

I thought I saw a recent thread/post saying the TSB with 10% increase did not exist but had become a bit of an "urban legend"?
Do you have the bolts Roger? Add them to the list I sent yesterday.
When mine came out they seemed to have a red thread locker on them. What is the difference between blue and red Loctite anyway?