Suprang

Hey guys, just got my 85.5 na 944 about a month ago... Been working on it since. Much to learn, as I'm used to working mainly on Supra's.

Anyways I have a vibration ~ 3200-3600 rpm. It vibrates a lot through the shifter (not the steering wheel). More noticeable in lower gears and can be felt in neutral with no change whether the clutch is engaged and disengaged

Originally I had a lot more vibration since I still had the original rubber center clutch. That was replaced.

I was planning on replacing the timing belt even though it looks good, so tonight I pulled off the balance shaft belt thinking it was probably out of alignment... Now the car vibrates more at other rpm ranges but can still be felt @ the range in question (seems milder, but may be due to the fact that everything vibrates more). Sounds like a balance issue but can't figure it out. Is prying on the motor a good enough test for motor mounts? Anyways, help is appreciated.

COLES (CLIFF'S for USA) NOTES: vibration @ 32xx-36xx. I think I've ruled out TT, BS belt, clutch, tranny.

Thanks,

Ang

kbower

Check the motor mounts. There is a spec for height the mounts are liquid filled when the liquid leaks out the mount collapses reducing height

Yarf

Motor Mount information:
http://www.clarks-garage.com/pdf-manual/eng-11.pdf

Matt O.

Same issue years ago, motor mounts. That's where I'd start.

Ben951S

Went from perfect to a similar, occurred in neutral (or driving). The O/U rollers were installed 180degress out when I had a shop do the timing belt. Very specific vibration ONLY at that RPM (mine was 3800 or so IIRC). They said my transmission was going. Jerks. Had some one knowledgable make the fix (just rotating them or swapping upper and lower, I forget)

Suprang

Thanks for the quick responses. I ordered some new engine mounts. Doing the timing/bs belts now. I'll post the results.

MAGK944

+1 it's your balance shafts, out 180deg, easy to get wrong and you will swear you have them right.

It's NOT the engine mounts, they cause vibration at idle which you don't say you have.

Richgreenster

+1

I have seen quite a few 944 with the balance shaft(s) 180 deg. off.

BeerBurner

I once had a similar vibration from my balance shafts being off by just a few teeth.

BB.

Suprang

I pulled my balance shaft belt off though... Vibration's still there. Anyways we'll see what happens, I'm doing belts first since the mounts will probably take a while to get here.

Thanks again

River

+1 on the balance shafts as well. Apparently it's really easy to mess it up with the U and O. U meaning UNDER, not UP. lol! So a lot of mechanics can easily mess it up.

You pulled your balance shaft belt off? That might kinda sorta make it vibrate..oh, just a little, lol!! Put on new belt, check your rollers and set things proper, it should be smooth.

Suprang

Changed the belts. It's still there. Just to confirm (I've researched it via search and clark's garage extensively); If everything lines up at TDC and the balance shaft pulleys are set up properly with the notches and the upper "O" is in a window and the lower "O" is in a rectangle they can't be out of sync right? Honestly, preliminary testing of running a balance shaft belt vs not running one seems pretty minute in the vibration of the car... Which leads me to believe it's something else.

944_S_TYPE

Any chance you have a bad bearing on the Torque tube?