rwd driveshafts

[dern]

Sorry for the double post on porsche but it occured to me this would be a problem any rwd car enthusiasts could answer.

I started getting a knocking at the back of my 944 last night which is directly related to road speed and not engine speed and is more pronounced when warm and when cornering. It sounds exactly like the noise a fwd car makes when the cv joint on the drive shaft fails but with less rumbling. I've changed a few fwd driveshafts but never yet had a rwd driveshaft fail so don't know what it sound like.

I jacked the car up and found I have rotational play in the inner cv joints on both driveshafts. Would this indicate wear or is there supposed to be some play?

Thanks,

Mark

[GreenV8S]

I've been through several rear CV joints and they produce exactly the symptoms you described. In my experience it is worth replacing them as a pair since they tend to wear out together.

[dern]

GreenV8S said:

I've been through several rear CV joints and they produce exactly the symptoms you described. In my experience it is worth replacing them as a pair since they tend to wear out together.

Ok thanks. When you say a pair do you mean both inner CVs or replace both CVs as a pair on each side? Logically I assume you mean the latter but my wallet is ever optimistic

Thanks,

Mark

>> Edited by dern on Tuesday 23 November 13:18

[williamball]

I had a 944 and a 944 turbo years ago - did maybe 200,000 miles between them. I had the symptoms you describe a number of times. Ranging from a slight knock to a seriously loud and worrying knock, always from the driveshafts and thus related to roadspeed.

Every time, taking the driveshaft out of the CV bearing at the transaxle end and repacking with grease solved the problems...at least for another 40,000 miles or so

Although it sounded expensive, mine never needed new parts, just a repack with grease.

WB

[dern]

Cheers. I'll take them off tonight... am I right that they are simply unbolted at both ends and I don't have to take the wheel hub off?

If it's as easy as it appears then I may give that a go.

Regards,

Mark

[williamball]

I've got to be honest and say I can't remember what had to be unbolted. It was maybe 15 years ago, and I've messed about with so many other rwd and fwd driveshafts/CVs/boots since, I can't remember precicely what had to be undone. Thinking about it, I can't actually remember what the rear suspension of a 944 looks like! And I had them for 8 years or more! Must be senility kicking in.

I do know that no special tools were required (as I didn't have any), and I'm sure only one part of the suspension had to be unbolted to let everything swing out to let the driveshaft be pulled out. It was certainly a quick job to do, and I could do both sides in an evening. Sorry I can't remember any more.

WB

[dern]

williamball said:

I've got to be honest and say I can't remember what had to be unbolted. It was maybe 15 years ago, and I've messed about with so many other rwd and fwd driveshafts/CVs/boots since, I can't remember precicely what had to be undone. Thinking about it, I can't actually remember what the rear suspension of a 944 looks like! And I had them for 8 years or more! Must be senility kicking in. I do know that no special tools were required (as I didn't have any), and I'm sure only one part of the suspension had to be unbolted to let everything swing out to let the driveshaft be pulled out. It was certainly a quick job to do, and I could do both sides in an evening. Sorry I can't remember any more.

Lol, no worries

Thanks anyway,

Mark

[dern]

I took the noisiest drive shaft off this evening (althouth it was the one with least play) and the grease was lumpy and dry so I hoped I'd be able to repack them but once the cvs were clean I could see the inner races on both end were pitted, scored and showing signs of localised heating so I'll be ordering 4 new cvs in the morning.

Removing the driveshafts was dead easy once I had a splined driver, you just undo the bolts and each end and it falls on your forehead which sets you up nicely for a 'quick' game of hunt the circlip in the dark

Regards,

Mark

[GreenV8S]

dern said:

When you say a pair do you mean both inner CVs or replace both CVs as a pair on each side? Logically I assume you mean the latter but my wallet is ever optimistic

I mean inner and outer on one side. (They run through the same angle, and see the same torque, so can be pretty sure if one is knackered the other will be too.)

[dern]

GreenV8S said:

I mean inner and outer on one side. (They run through the same angle, and see the same torque, so can be pretty sure if one is knackered the other will be too.)

The wear on the inner and outer was indeed more or less identical on inspection of the bearing races.

Regards,

Mark