I am having an engine vibration primarly felt through the shifter right at 3000 RPMs. I have check, rechecked the balance shaft positions repeatedly and have them set to the illustration shown elsewhere on this forum (top shaft has the O visible through the large round opening and the bottom shaft O is visible through the rectangular opening in the cover plate. I have tried positioning the top shaft with the hash mark on the engine cover mark, as well as the O, on the engine cover mark. The bottom shaft is dead on plastic tab. It doen't seem to make much difference. The shifter vibrates badly at 3000 rpms accelerating and decelerating. Engine mounts have recently been replaced and it was no help at all. Furthermore, The transmission oil cooler tube has been snapping in half I believe due to this vibration. Anybody have any ideas?

 

Has your transmission been out of the car recently?

Several dowels locate the transmission to the torque tube. For whatever reason, these get left out sometimes during reassembly. Always results in a vibration at around 3000rpm.

It could also be balance shafts but you've already checked that.

 

Believe it or not a bad or a few bad exhaust mounts (rubber ones) will give you nasty vibration through the shifter.

 

Also engine mounts...

 

I'll second Jeremy on that, check your exhaust's rubber mounts, mine were bad/missing on the two that run under the torque tube and fixing them got rid of a whole lot of buzzy noises and vibration. Cheap fix and if they're the originals they're probably going to die pretty soon anyway.

With the oil cooler tube snapping though I think I'd look at something like the dowels like ninefiveone suggested. A bit of annoying vibration is one thing, parts breaking from vibration is a much bigger concern..

For what it's worth I still feel a little more vibration than I'd like at about 3200 which I think probably is the balance shafts, my belts have about 5000 miles on them and the shop where the PO had them done doesn't really specialize in Porsches (just euro cars) so it's pretty likely they could have been off a tooth or two. I'm pretty sure my engine mounts could use replacing too but it's a low priority fix.

If I was breaking the oil cooler tube though I'd be looking for something bigger, that shouldn't happen unless something is really out of whack.

 

oil cooler tube ????????? where/what is that?

 

Doug,

I had the same thing happen to me----seems my turbo ball bonder had blown a gasket!

Your buddy,

Cy


ps you should send the bill to your tranny mechanic Bob

 

I also recall reading that if you installed one of your rollers on backwards, vibration can occur. Good luck and please close the loop by letting us know what you find.

 

Well, at the suggestion of NineFiveOne - I checked the dowells in my transfission mount. There are two hollow sleeves that the two upper mounting bolts go through & other than that I could not find any others that were supposed to be there. However I did find that the coupling sleeve that secures the main drive to the transmission had the rear bolt comming loose. I tightened and torqued both of them and the vibration got a little bit better, but was still there. I have literally been trying to track down this vibration for over 2 years.

Well I finally decided it must be the torque tube. A friend of mine gave me a used one that had just under 70,000 miles on it, (mine has over 170,000 on it). Well I got into removing the torque tube and finally got it out. (God what a piece of work that is) Well the torque tube was definally toast as there was quite a bit of play in the engine side bearing. I decided since I had never replaced the clutch that now was an good time to do so, I pulled the clutch off and discovered the true source of the vibration. The 6 small springs that are mounted near the center of the pressure plate had completely broken off and were floating around the clutch. The metal plate that held the 6 springs to the pressure plate had also broken free and had been rubbing on the nipple of the drive shaft right at the end where it slips into the pilot bearing. It had been rubbing on the drive shaft so long that it had worn it 1/2 into.

Well I replaced the clutch and installed the used torque tube and now the vibration is truly gone.

Thanks for everyone's help in tracking down this menacing problem.

d

 

Hey, great to see it worked out. Nothing better than banishing an annoying/destructive vibration.