Shifting noise

[Rjackel944]

okay so lately I've been hearing a clunk when shifting. It's not really bad, but definately noticeable. It's not when pushing in the clutch, or letting out, but the actual throw into gear makes the sound.

It doesnt make the sound when i shift around 4k rmp, but at 2k rmp shifts its noticable.
Also seems to be more 2nd to 3rd and 3rd to 4th, and also when the engine is warm. Cold shifts seem to be fine.
Lets see what else. oh. Turning the half shafts, there seems to be some play at the transaxle side. Idk maybe a little less then 1/8 inch movement on both sides. Is that normal?

I recently repacked my cv's and the bolts were coming loose, (and actually came off when driving ) and i know that can cause this. But I'm working on loctite-ing and torquing them all the way tonight.

Can anyone help me out? Thanks!

[John_AZ]

If your CV bolts come loose after you torque and apply LocTite to the threads, it might be time to get new CV bolts (actually Porsche recommended action) or look at Ideola's "super" Stage8 Locking CV bolts.

Ideola's Garage: Products & Parts for Transaxle Porsches

Other suggestions would be to drain the transaxle fluid into a pail with a cloth over the top. If you see a few slivers of steel, you may need to buy a used transaxle or pay to get fixed.

GL
John

[Rjackel944]

Yeah I looked into that. Its been a few weeks since my incident with the bolts, and they're still solid. But I did look into ideola's bolts.

IIRC, when I changed my transaxle fluid, there was some metal stuck to the magnet on the drain plug..

[mayPOR944]

my car does the same thing i know it has a bad clutch could that be the noise?

[Rjackel944]

Where exactly is the clutch inspection hole? Is it viewed from under the car?

mayPOR944, does your shift clunk vary with RPM?
I'm really hoping its not the clutch..

[John_AZ]

Originally Posted by Rjackel944

Where exactly is the clutch inspection hole? Is it viewed from under the car?

mayPOR944, does your shift clunk vary with RPM?
I'm really hoping its not the clutch..

Ah, an easy Q.

Clutch inspection hole:
Checking Clutch Disc Wear

You may want to pull the starter (disconnect the battery first) and check to see if you have chunks of rubber or steel in the starter area.

GL
John

[Rjackel944]

I've looked at that page, but I'm fairly new to this i dont know exactly what i'm looking for. and the picture didnt show me where it is in relationship to the car.

When it says its on the left hand side of the clutch housing, is that driver side or passenger side?

[John_AZ]

Drivers side by the clutch slave cylinder. If you are very lucky there will be a black rubber 2" inspection cap. Usually these are missing. You will see the clutch fork "cup"end where the slave piston pushes.

To measure the distance easier, get a few metric deep sockets and slide one inbetween the bell housing and the clutch fork until it is very snug. Then measure the socket.

GL
John

[Rjackel944]

Thank you for the help! i measured 18mm.. a half inch socket fit right in there and the OD of it is 18. But isnt that the distance for a new clutch? The car was advertised as having a new clutch, but I wasnt quite sure i believed that (no records).

Well, now that its out of the question (or is it?) what else could be causing this "clunk"?

I'm thinking it might be back at the transaxle (or torque tube), where the half shafts connect.. It seems like its got a split second "lag" before it grabs, causing the clunk. Any thoughts on that?
Your help is greatly appreciated. It brings me hope for my car lol

[John_AZ]

OK, good news about the 18mm.

At the back of the car would be the 2 drive axels and CV joints. Are the CV bolts tight? Get an 8mm--------- 12 point/triple square/XZN/Cheesehead whatever you may call it------hex and check each bolt.

The next check is to see if the transaxle has chipped gear teeth. Drain the fluid and put a rag over the bucket to see if you have any silver slivers from the gears.

For now, fill with the cheap Valvoline HD Gear Oil from Checker/OReilly. This is the good conventional gear oil for our hypoid gears. Save the money on the synthetic gear oil until you find the problem.

If the clunk is still there, it could be the ring and pinion gear going bad.

GL
John

[mayPOR944]

i changed my transaxle fluid this year hasnt been changed in 10 years could be original, ever since the clutch went bad thats the noise i have been hearing the "clunking well shifting gears" so is it clutch, cvs, or transaxle?

[Rjackel944]

Thanks so much John, I appreciate your concern and help!

The cv bolts are tight. I repacked them recently and i torqued them all down after they did come loose, which did make that clunking sound.

As for the fluid, I changed it last month. If I remember correctly, there was a magnet on the drain plug, and there was microscopic metal shavings on there, but no big pieces. I assume this is normal though.

i think i'll look into the ring and pinion gear..

[Rjackel944]

I did a search on the ring and pinion gear and came up with a test that involved jackin up the rear end and making sure both wheels turned when you spin one wheel, with the car in gear.

I did this and both wheels did turn, however, there was about 2 inches of "play" where the wheel turned untill it caught and spun the other.

COuld this mean my ring and pinion gear is going out?

Any other suggestions for things to check for?

[John_AZ]

Have you checked the driveshaft coupler? Unusual but it may be loose. Pull the transaxle front inspection rubber and make sure the coupler bolts are tight. Use a high quality 8mm hex----DO NOT STRIP the threads.

I think your R&P is OK.
Here is a picture of a R&P with bad teeth. If you had the car on a hoist running and shifting into gears you will hear a few or many "marbles".



You could pay a mechanic to test the car or get a $250 used transaxle spare (typical price and up) and see if the clicking goes away.


Here is a clutch diagnostic page. The PO (past owner) may have put in a new clutch disc but saved a little on the needed replacement parts.
New Pilot bearing
New fork rod bearings-2
New Throw Out Bearing guide tube
Clutch fork not with in spec
Clutch fork rod with deep needle bearing marks----should have been replaced

Just random guesses.
http://media.centerforce.com/DiagGuide/DiagnosticGuide04DL.pdf

GL
John

[Rjackel944]

Thanks again John, without you I would not have any idea what to look at.

Seems as if its entirely coming from the rear end. Either the transaxle and/or Torque tube.

I noticed sometimes it shifts perfectly fine , with no noise at all.

Tomorrow i'll look at the driveshaft coupler.
Thankyou.

[Rjackel944]

Is this the driveshaft coupler your talking about? It seemed pretty tight.

[John_AZ]

Yup, good.

The next test is for the torque tube/drive shaft bearings.

Get on real quiet road about 35mph. Press the clutch in and slightly step on the gas to about 3500-3800rpm. Is there any vibration? If you feel vibration it is from the clutch. Usually the FW and PP not balanced.

OK, still at 35mph, shift from 3rd to 4th at about 3800rpm-4200rpm and try to notice any vibration from the torque tube/drive shaft.

If you noticed any vibration from 3rd to 4th you may have bad torque tube bearings and maybe this could be the clunk you hear. The bearing carriers failing. The TT has 4 big bearings.

Or maybe it could be bad rear axel bearings.....

Porsche4life just mentioned to check the trans mounts in another recent post. Good idea.

GL
John



John

[Rjackel944]

Lets see. I ran the tests you suggested.

No vibration that i could tell when reving to 3500 at 35mph.

I couldn't feel or hear any vibration when shifting 3rd to 4th at 4000rmp. But there wasn't the clunk sound, it shifted very smooth

Just a few more distinctive points i wanted to point out:

1) when at idle, there is some rattling coming from the shifter area. It goes away when the clutch is pressed. Now there isn't the inside rubber boot, so this might be normal.

2) I noticed when crusing, usually in 5th (but i havent tried in any other gear), if i push in the clutch, and then let it out normally it makes the clunk sound.

3) most of the time it doesnt clunk going from 1st to 2nd

Thank you so much for your helf thus far. As far as the transaxle mount, what should i look for to see if mine are bad?

[John_AZ]

Originally Posted by Rjackel944

As far as the transaxle mount, what should i look for to see if mine are bad?

Loose bolts or cracked rubber.

Some members stiffen the trans mounts with this DIY----maybe in the future.
Homemade Motor Mounts

The rubber shift boot and the torque tube sound deadener/insulation under the shifter should cure the noise.

I am not sure what to suggest about the 5th gear noise other than to guess the transaxle-----where you began.

GL
John