Blew up another CV joint..., What to do? Options

[HAM Inc]

Make sure the tranny is centered between the trailing arms.
Also, with the rear off the ground and the trailing arms at full droop grab the axles and make sure you have plunge in both directions. Next remove the springs and run the trailing arms to full bump, (stopping on the way up at ride ht) then recheck the axles for plunge.
The fact that the two failures occurred to the same joint position has me wondering if the tranny is off center.
If the drive train is moving in the car in hard corners it can shift toward the outside wheel and jam the axle. Look in the inside of the tranny drive flange for evidence that the axle has been jammed into it. Use only Lobro joints. If everything is installed correctly it will take more torque to break a CV than you'll get out of a normally aspirated 2.0l. A lot more.

[yarin]

Eric sent me a new CV no charge, got it a few days later. I pulled everything apart and came across something a bit odd during installation. The new CV slides easily over the splines of the shaft with no resistance at all. Furthermore, there is a tiny bit of slop between the splines of the drive shaft and the inner race of the CV. I took a few shots and snapped a quick video. Let me know what you guys think. I was hoping to autocross tomorrow, but I decided to cancel due to this area of concern. I've installed five of these joints before, all require significant force to press the inner race onto the drive shaft. In order to remove the old CV, I needed a bearing puller. Something is strange... is this a concern or am i crazy?? Is the driveshaft too small, or CV inner race too big?? My first guess is that the CV is the issue since the previous CV was a tight fight.

[yarin]

more..

[yarin]

Here is a quick video I shot illustrating the concern I have http://video.google.com/videoplay?docid=51...39578&hl=en

[Katmanken]

All of mine slip on without pressing. That does look a little large, but then again, the newer parts ain't what they usta be.

And don't look a gift CV in the mouth...

Hows the tranny and engine mounts, and the training arm bushings???????

Ken

[yarin]

The tranny mounts are the solid hard mounts, engine mounts are good as well. I'll look at the trailing arm bushings next time.

Any comments on the slop of the inner race on the drive shaft spline? There is a small amount of slop as seen in the video, however the CV itself is tight. Run with it or find another CV? Five of the last CVs I installed were extremely tight, this one slides on by hand and can be rotated ever so slightly. (IMG:style_emoticons/default/confused24.gif)

[yarin]

Bump.. anyone care to share their CV installation stories? How much rotational slop is OK?

[John]

I was about to reply that mine typically slip onto the splines without much force, but after watching the video, I changed my mind.

I can't tell exactly from the video how much slop is there, but it looks like the inner race twists on the axle shaft splines. I don't think it should do that. Have you tried a different axle shaft for comparison?

Could pulling your old CV inner race off the shaft have damaged the shaft splines?

I wonder if the inner race was smashed by the old broken joint to the point where the splines were crushed and now the new joint is now a loose fit on the splines.

I wish I had a definitive answer for you, but I do not. I would try a spare shaft with the new joint.

Good luck with it.

John

[racerx9146]

I have a lifted Vanagon Syncro with 230 HP Subaru SVX motor running the original CV's. I drive it hard and the CV's are still holding. They have tons of rotational slop. Other Vangon guys seem to snap em constantly. Same with my 914. 20 years of beating on the street and the autocross track the still holding up!

I think its a mystery why some fail and some last forver. "knock on wood"

Daron

Bump.. anyone care to share their CV installation stories? How much rotational slop is OK?

[jhadler]

Just thinking out loud here...

Do you run on a particularly grippy surface? Concrete? Race track quality or hard, coarse asphalt? One thing to possibly suspect is flex in the trailing arm or the mounting points. If you're placing a significant side load on the car, and the chassis or suspension is flexing excessively, it's possible you could be placing too much of an axial load on the CV.

That it seems to be occurring on only one side implies a possible external cause.

If this makes sense, I'd check the trailing arms and trailing arm mounts for any signs of flex/fatigue/wear/cracking. Either that, or you're running your courses on part of an oval track, and use the same banked turn at most events... (IMG:style_emoticons/default/biggrin.gif)

Just a thought...

-Josh2

[ericread]

Just thinking out loud here...

Do you run on a particularly grippy surface? Concrete? Race track quality or hard, coarse asphalt? One thing to possibly suspect is flex in the trailing arm or the mounting points. If you're placing a significant side load on the car, and the chassis or suspension is flexing excessively, it's possible you could be placing too much of an axial load on the CV.

That it seems to be occurring on only one side implies a possible external cause.

If this makes sense, I'd check the trailing arms and trailing arm mounts for any signs of flex/fatigue/wear/cracking. Either that, or you're running your courses on part of an oval track, and use the same banked turn at most events... (IMG:style_emoticons/default/biggrin.gif)

Just a thought...

-Josh2

So maybe it would be a lot safer for him to go the opposite direction at the track next time? Seems like you would be dodging traffic all the time???

(IMG:style_emoticons/default/biggrin.gif)

[J P Stein]

Like HAM I think there is something specific to your car.

I have never broken a CV (yes, I'm knocking wood) and God only knows how many miles are on them. If they were inherently weak I think I would have broken one considering the use I put then to.

I check for slop often by just grabbing the axle and turning back & forth...feeling /listening for movement. There should be at worst a minute amount of slop...none is preferable. To remove them from the splines takes a couple light taps with a punch & hammer.....no slop there. Moly grease, of course.

Not much help here, eh? (IMG:style_emoticons/default/confused24.gif)