Help needed with axle noise please

terryb · 03-19-2006, 01:29 PM

I've been trying to diagnose what's causing a thump during left hand turns and I think my dad and I found it this morning.

When I move the driver's side axle back and forth (toward and away from the wheel), the side closest to the engine makes a kind of thunk or clunk sound when it reaches the end of its travel toward the wheel. The drive's side axle is much easier to move than the passenger side, which doesn't make this sound. There's about an inch of travel for both sides.

What does this sound mean? Inboard CV is bad? Something worse? Is it dangerous to drive? Help please!

Thanks.

BeauBlues · BeauBlues's Garage

Sounds like a bad CV. Check the rubber boots for any cracks. Any contaminents in a CV can cause it to wear out. There was a thread a while ago about CVs. Reconstructing CV's

terryb · 03-19-2006, 03:33 PM

Thank you BeauBlues, I found that thread last night which started me investigating the CV's. I don't see cracks or grease around any of the boots.

I can't picture in my head what the inboard CV internals look like, but the sound makes me think that as the axle moves toward the wheel it bottoms out causing the sound. The sound is definitely coming from the inboard side of the axle.

Looking through it again, I can't find the posting in the Reconstructing CV's thread, but if I recall correctly a bad inboard CV can be replaced on an '88, but not an outboard. Is this correct?

Other than the CV, what else might this be? Something in the tranny maybe? I guess I'm wondering how effed I might be.

Thanks.

BeauBlues · BeauBlues's Garage

Terry, just to make sure, when you are checking for the noise, are you trying to twist the axles? My point is that a good working CV should not be able to twist. I doubt that there is a problem with your transmission. Also if it is the inboard cv(the one that connects to the transmission) then yes you can replace it, our host sells them for under $80.

Just make sure that, while you are in there, tearing your axles apart that you check all your CV's. Just in case.

terryb · 03-19-2006, 04:36 PM

No, I wasn't trying to spin the axle. Only moving it back and forth perpendicular to the direction the car travels. Both axles had about an inch of back and forth play.

Following some of Grady's advice in the Reconstructing CV's thread, I left the car out of gear up on the lift so I could spin the wheels and listen to see if the CV's made any weird sounds. I didn't actually try to spin the CV's using the axle, just the wheels.

Thanks for the good advice BeauBlues, to check both CV's when the axle is out, although I'm not sure I have the wrenching experience to notice a potential CV problem unless it's an obvious one.

Thanks for the ray of hope that it's not something really $eriou$!

BeauBlues · BeauBlues's Garage

You are most welcome for the help. Im very surprised that no one else chimed in so far, but now that I know that your axle actually moves in more than I expected, I can pretty much guarantee that your CV is bad. Consider your self lucky that it did not come apart while you were driving. Oh how I have heard the horror stories.

Nine9six · Nine9six's Garage

Perhaps no one else chimed in because they think BeauBlues hit the nail on the head with his response.
terryb,
Try taking a pair of big channel locks to the axel and see if you have any radial play. Do this with the car safely jacked up, and the emergency brake engaged. If you have radial play, I'd say your inboard CV is shot.

rs911t · 03-19-2006, 05:47 PM

It's the CV joints. I pulled the CVs off the 930 last Spring. No obvious holes in the boot, but they were completely dry and toasted.

terryb · 03-19-2006, 10:48 PM

Thank you BeauBlues, Nine9six and rs911t for your advice and insight.

BeauBlues, are you saying that an inch of travel toward the wheels is too much? Both axles have this much play.

Nine9six, I will try your channel lock test tomorrow. Safely supported of course.

rs911t, I had Jae at Mirage replace the outboard boot on the driver's side about a year ago because it had torn and spewed grease. We looked at the CV's when the axle was off and he thought they didn't look bad.

I have done more AX'ing since then and spun once last year. I was so suprised by my first spin that I didn't push the clutch in right away. Could this be the cause of the CV failure?