jbrill

upon further inspection today, it looks as though the sound is only noticble when the transmission get nice and warm. I was coming down the highway today and then parked after that and noticed the sound, however it was not there before the run down the highway. Here is what im thinking:
When the tranny oil gets warm, its breaking down due to age and not being changed.. EVER (P.O.) therefore the oil turns to the viscocity od water and doesnt provide evough lubrication.

Im going to fill it up with 80/90 synthetic tomorrow (unless there is a better oil to use) and add a lucas oil additive.

thoughts?

Oddjob

Now your description sounds more like pinion bearing noise. Makes a rattling noise when in neutral with the clutch out, sitting at a stop sign? Sounds like marbles rattling around inside the trans?

When the trans is cold, the fluid is thick and the bearings do not make much noise, but when the fluid gets up to operating temp and thins out, the bearings do make more noise when unloaded.

Did you replace the original rubber center clutch with a spring centered clutch? Has the noise been more audible since that replacement? If so, the spring centered clutch will transmit more vibration from the engine, through the driveline to the transmission, so you will get more rattling from the pinion bearings.

As the bearings wear, they get looser, and will make more noise than when new. But since your car is low mileage, Im going to assume that the bearings are not overly worn, and what you are hearing is probably normal for a 944 series trans.

Replacing the fluid may help slightly, but I would not expect it to eliminate the pinion bearing noise.

jbrill

great, thanks for your help. yes i did replace it with a spring centered clutch. and yes it made more noise after. It does sound like marbles that is a great way of describing it! how hard is it to replace the bearings? i knwo 944 trans make alot of nose... i just dont think its supposed to make this much lol.

wat oil do u suggest to put in the trans?

Rich Sandor

Hey Jordan, let's hook up this weekend and we'll compare - mine makes noises too but I know what's causing mine...

Also you might have some gear fragments floating around too inthe tranny fluid.

Oddjob

The pinion bearings are a major effort to reshim and/or replace. You should only go to this trouble when completely rebuilding a worn out trans, so expect something in the $1500-2000 plus range for a rebuild, by a reputable shop.

Hopefully, you do not have abnormal noise or problem.

75 or 80w-90 weights are fine. You can do search on here for trans fluid recommendations, there are various brands guys use. Synthetics are good, but some recommend a friction modifier w/ the synthetics to get better synchro engagement and for clutch type LSDs. Mobil 1, Redline, Amsoil, Swepco, etc....

AndyK

I have this SAME problem, down to the whine/grind when I make a sharp left turn! Sitting at a light, with the clutch out, the noise sounds like marbles rattling around. New spring centered clutch amplifies the sound, but it was there when I bought the car. And, when the car is cold, I don't hear this sound. My mechanic says it's standard 944 noise. My tranny was replaced by Porsche at 50k, so it only has 60k on it.

I'm curious to hear if the new tranny fluid lessens the noises!?

skene

When I first got my car it had a decent amount of transmission noise on decelerating in my car as well. I put redline MT90 in it and that seemed to get rid of a lot of the noise.

When I had my clutch replaced a couple months ago the shop put Mobile 1 in it and it's louder then it was when I first got it. I've got a couple quarts of redline heavy duty shockproof sitting on a shelf that will hopefully quiet it down again.

The clutch in while in neutral is a bit odd though...that and the low mileage makes me wonder if the transmission is where the problem is though. Either way, gear oil is pretty cheap and not too difficult to change so you might as well give that a try.

jbrill

I will be changing it today, and i will let you all know about my success!

anyone ever used "Royal Purple" ? Its expensive stuff, ive used it in presvious vehicles and it sis amazing!

MAD MAC

Maybe thew cv's then. they wear pretty quik in these things.

MAD MAC

You could change the fluid and make sure to check for shavings also. If you find sone then you may have a trans prob.

jbrill

going to change the fluid and then go over the whole car re-torquing all the bolts i removed to do the clutch job.
then have to pull both door panels off to fix a rattle i have in each door, then i have to adjust the hatch so it works properly, then i have to adjust my shifter, and then rebuild my window switch for the passenger side

oh its going to be a busy day!

MAD MAC

My car had a grind and pop noise, with many of the same symptoms.; Just thought Id mention the cv axle since that's what I had to replace. While you're at it you could pull one down to check.

jbrill

yea good idea, i'll do that too!

MAD MAC

I just don't think it's your trans. The car sounds like it's in good shape. Unless the previous owner was a jerk with the shifting. My car has 250K and makes no noise, and the trans is as smooth as silk.

jbrill

looks like i fixed the problem!

A) changed oil in tranny to a bit thicker
B) Adjusted shifter

and all is well. car makes way less noise.
still makes a bit, but im going to short run this fluid and then fill with swepco ina few weeks.
I found no metal shavings in the old fluid.