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Sudden 944 driveline failure - transaxle, or something else?

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Old 01-24-2010 | 08:11 PM
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Thumbs down Sudden 944 driveline failure - transaxle, or something else?

I have a somewhat neglected 1986 944 N/A that I'm slowly nursing back to health. I recently got it back on the road after replacing the clutch hydraulics (seals let go when the weather turned cold), but now I'm facing what appears to be a more serious driveline problem.

While I was driving to the grocery store, a car in front of me braked suddenly to make a turn, forcing me to slow down. After it finished turning, I downshifted to 2nd gear and attempted to accelerate briskly. As soon as I stepped on the gas, I heard a series of metallic rattling noises from the rear of the car accompanied by a complete loss of power to the wheels. I coasted into a parking lot and discovered a flood of hypoid oil gushing from the transaxle.

I'm pretty sure the clutch is still working - when I put the car in gear and let the clutch out, there is a small amount of noise that sounds like bearings spinning (presumably in the torque tube or trans input shaft.) The oil leakage leaves me confident that the trans itself is the issue, but is there anything else that could be at fault? Is this kind of failure (absolutely no power to the wheels in any gear) consistent with a catastrophic failure of the ring and pinion?
Old 01-24-2010 | 08:25 PM
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that sounds bad !!!!!! I would say sounds like a new box is in order.
Old 01-24-2010 | 08:53 PM
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New box it is, unless your able to remove and diagnose the gearbox yourself. Can you tell where the fluid is comming from?
Old 01-24-2010 | 09:08 PM
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It could still be the clutch center... or both the clutch center and the trans, if you have been driving on a blown clutch center for a while.

You can get the car up on jackstands and see if the driveshaft can turn with the wheels by looking at the coupler at the transaxle. With the car in gear, turn one rear wheel and block the other (I'm assuming you do not have option code 220.) The coupler will turn if the R&P is still there. If not, it won't. That also assumes your shift linkage has not fallen apart.

If that coupler turns, pull the starter and look for rubber chunks, and ask yourself why you were driving around with a loose, clunking driveline until the tabs broke off the clutch disk.

-Joel.
Old 01-24-2010 | 09:14 PM
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The fluid could only be coming from the box. Good news is a used box can be had pretty cheap.
Old 01-24-2010 | 09:49 PM
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I had the starter out a week ago when I changed the clutch slave cylinder. As a precaution, I checked for evidence of clutch deterioration. There was no debris (rubber or otherwise) in the bottom of the clutch housing. The shift linkage appears to work, since the reverse lights come on when I shift into reverse (my understanding is that the lights are wired through a switch on the transaxle.)

I have not had the opportunity to put the car on stands and examine the driveline further - my driveway is far too narrow for a flatbed truck, so I had the car dropped off on a nearby side street. Given that the gearbox is clearly leaking fluid, it seems like it would be a waste of time to attempt further driveline diagnostics.

Does anyone know of a source for a good used N/A trans, and/or a good mechanic in the metro Atlanta area? I don't think I can tackle the transmission swap myself with the car on the street.
Old 01-25-2010 | 10:18 AM
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Originally Posted by Potomac-Greg
The fluid could only be coming from the box. Good news is a used box can be had pretty cheap.
Exactly right.


The only other option is the "gear oil" is really CV grease. That would be if you are lucky and it is rather commong to have CV bolts back out after a clutch job. That is the only source of oil in the back other the the gear box.

Very easy to tell however. Just jack it up and look. Remeber gear oil means a hole the tranny case and 2+ qts of fluid. A noticeable, but smaller volume could be liquified CV grease dripping out from a joint poping of.
Old 01-25-2010 | 11:13 AM
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Try draining the tranny and take a look at what comes out. When I blew my second gear, the fluid looked like metal soup. Clean fluid won't rule it out, but metal chunks/flakes will pretty much confirm it is bad.
Old 01-25-2010 | 12:38 PM
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Originally Posted by M758
Exactly right.


The only other option is the "gear oil" is really CV grease. That would be if you are lucky and it is rather commong to have CV bolts back out after a clutch job. That is the only source of oil in the back other the the gear box.

Very easy to tell however. Just jack it up and look. Remeber gear oil means a hole the tranny case and 2+ qts of fluid. A noticeable, but smaller volume could be liquified CV grease dripping out from a joint poping of.
I agree could be a busted CV joint if one breaks the car wont move... but if it is gear oil it will have a smell to it -which personally i hate- the CV grease dosent...

Im not sure but imma throw it out there but with my experience with very old and/or high mileage VW transmission there is "rivets" that hold the diff gear to its mounting plate the rivets go bad and cause the gear to cut a hole into the case...

http://www.qualityvwparts.com/

http://www.vwtransaxles.com/rivet.html
Old 01-25-2010 | 08:11 PM
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Originally Posted by M758
The only other option is the "gear oil" is really CV grease. That would be if you are lucky and it is rather commong to have CV bolts back out after a clutch job. That is the only source of oil in the back other the the gear box. .
It's gear oil. The smell of sulfur is unmistakable, and it's clearly oil - not viscous glop like CV joint grease.
Old 01-25-2010 | 08:32 PM
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Easy answer here. You more than likely grenaded your R&P, which in turn blew a hole somewhere that let all of the oil drain out. If someone has been doing burn outs in that car (you said it was neglected, then this is more than likely). this will happen.

Ive gone through 3-4 N/a transmissions.
Old 01-25-2010 | 09:33 PM
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I was thinking R&P too.
Old 01-26-2010 | 12:28 AM
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Originally Posted by Rock
Easy answer here. You more than likely grenaded your R&P, which in turn blew a hole somewhere that let all of the oil drain out. If someone has been doing burn outs in that car (you said it was neglected, then this is more than likely). this will happen.

Ive gone through 3-4 N/a transmissions.
you must do a helluva lot of burnouts then...because i'm on the stock n/a trans that has 217,000 miles on it, the last 3000 of that with 350+ hp and probably 375 lbft of torque...and i have done several burnouts. Maybe my tires are getting old and don't stick as well, but the trans seems to shift smooth (except 1st to second) every day...do you think there were other things contributing to the destruction of your transmissions?

to the o.p. where are you? i have a spare trans that i could sell cheap, still need to pull it from the parts car, so it may be late february...would you be interested and are you close by?
Old 01-26-2010 | 06:30 AM
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Originally Posted by lovemyp-car
you must do a helluva lot of burnouts then...because i'm on the stock n/a trans that has 217,000 miles on it, the last 3000 of that with 350+ hp and probably 375 lbft of torque...and i have done several burnouts.
The planets must be aligning perfectly for you then.

I've blown more N/A ring and pinions than Rock and I don't drive like an *** at all. As I've covered in various posts before, N/A transaxles are inherently weak and are further compromised by many issues that creep up over time. I won't go and re-hash all of the issues but feel free to look them up.

In my case the contributing issues were (more than likely) autocrossing on fat, sticky tires. The dynamic load changes were just too much for the r&p.

You may disagree with me but you are driving on borrowed time with that N/A trans and that much HP. I'd replace it while you can still sell it, otherwise it will just end up being scrap when it blows.....

To the original poster in this thread, the r&p sounds like its definitely blown. N/A transaxles are fairly cheap. Look for a 88 or 89 model if possible, in my opinion they are stronger and less prone to failure.
Old 01-26-2010 | 01:05 PM
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Trans is easy to change by yourself you only need basic tools a pair of axle stands and a trolly jack.IF you can get someone to help you should do it in a couple of hours,even then you will have time for a couple of beers as you go.


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