Question about CV joints

Hello again Saab experts! My '90 900 non-turbo is starting to make clunking sounds from the front axle when I make hard turns. I'm guessing this is the outer CV joints. The car has about 75,000 miles. My question is whether I need to replace both the inner and outer CV joints to fix the problem. What's the standard remedy for bad CV joints on these cars? Some shops I've talked to have mentioned rebuilt axle assemblies, is this the usual way to go? The Saabsite offers the CV joints seperately. Anybody bought parts from them? Thanks for your input! David N. in California

Reply to
Studecom
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This is a very young age and low mileage for CV joints to fail, unless they've been running dry.

First do a visual check of the boots. How do they look? Are they split?

Second find a nice level bit of ground, and drive around in slow circles with steering at full lock, first clockwise then anti-clockwise. If a CV joint is failing, you will hear a steady clicking/knocking coming from that joint.

The answer is that you first need to identify the problem. There are in fact no inner CV joints - they are spider/cup drives, which are quite different with totally different failure modes.

CV joints are very tough things, and when one fails it's almost always because it's been run dry. Sometimes the ball cage will just fail, but this is rare.

Because of this, you normally just replace the failed joint. If it has failed because the boot has split, it's wise to replace all 4 boots at the same time.

Replacing a CV joint on a C900 is pretty easy, with no special tools/equipment required. As such, you would usually just buy a replacement CV joint.

Reply to
Grunff

I have had two CV joints replaced on my '86 C900, both before 50k. I never knew of checking the rubber boots so I had to pay (~$250/ side). They were the inner boots. Now I am starting to hear the dreaded 'clunk' again at 85k, this time the right outer boot is damaged. I've heard this is a common problem with Saabs. I checked the boots every oil change and only was aware of the broken boot after the noise started. Oh well!

--Paul

Reply to
P K

I checked the boots, and yes, some of them are cracked. I'm still not clear though on whether the sound I hear is coming from the inner or outer part of the drive axle. Is the inner part of the axle just as likely to fail as the outer side? I was guessing that the outer side would have more problems since it has to go though more change of angle since it is where the front wheel pivots when turning. Does this make sense? David N.

Reply to
Studecom

Obviously you have had the outer CV boots torn for a while?

The grease gets out and water&dirt gets in thus damaging the CV.

Obviously the clunks are coming from the CV which has torn boot - normally outer one.

Inner drives generate for example shudder while accelerating on tight curve etc. Clunks normally come from outer CV's when they are shot because of torn boot.

If you want to save $$$ there are some rules with CV's:

1) Inspect the condition of boot at least twice a year 2) replace the boot when it starts to have obvious cracks, but is not yet torn. 3) If the CV is not driven long time with torn boot, you might want to change the boot only. -Take the CV out of car disassemble it clean with petrol solvent -Assemble the CV put it new grease (MOS grease) and back to car. -do not overfill the grease as it causes the boot to torn again in no time -use only good brand CV's & boots - avoid cheap ones 4) Perfectionists would change the Grease in CV with 100k mile intervals 5) Changing the CV or Boot is rather good time to start practising DIY if one is interested, especially in OG900 it is so easy and straightforward.

I have 228k mile driven CV's... I've changed the boot numerous times on OG900 and 9k - In our climate it is necessary as boots are torn in approx. 40-50 k miles.

SuoTimo _____________

Studecom wrote:

Reply to
SuoTimo

SuoTimo, Thanks for the information! I think that I'm getting a handle on this now!

Reply to
Studecom

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