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> Blew up another CV joint..., What to do?
yarin
post May 23 2008, 09:34 PM
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So I need some advice on this one:

2 years ago a CV went on me during an autocross, drivers inside (tranny side). The bearing race cracked and well, u know what happens then, no power transmitted means flatbed tow truck home. Replaced all 4 CVs with the kit from PMB performance.

All was well.... fast forward to today, the exact same joint blew. I haven't dissasembled for a post mortem but it isn't pretty. Luckily i flat tow the car to events now so getting home wasn't a problem. The car definitely took a beating today, put about 45 total runs (autox school x 2 drivers) on the car before it let go on Avon Tech RA tires, a few areas of the course induced some slip/grip stress.

Motor is relatively stock, probably putting out about 100-110hp crank. AutoX definitely put exess wear and tear on the part, running semi-sticky tires.

So what should I do, replace with another kit? OEM? Beef it up with 944 or heavy duty CVs? Any of you fellow autoxers have a solution that won't cost me a fortune?

Thanks!

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yarin
post May 25 2008, 10:41 PM
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All great points once again! How can I manually check the side deflection of the trailing arm? I would imagine I need to induce a rather signifcant force to get any form of deflection. I'll take a look though. Bushings are on my list of stuff to do this winter.

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Jeff Hail
post May 26 2008, 01:28 AM
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QUOTE(yarin @ May 25 2008, 09:41 PM) *

All great points once again! How can I manually check the side deflection of the trailing arm? I would imagine I need to induce a rather signifcant force to get any form of deflection. I'll take a look though. Bushings are on my list of stuff to do this winter.

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Easy to do visually and by grabbing a feel.

Bushings, wheel bearings are easy to inspect- just jack up a corner and grab the tire in mid air, rocking back and forth with hands placed 180 degrees horizontally. See what moves. Now change hand position to 180 degrees verticle and try to rock back and forth. If the road wheel assembly still has the same slop or an audible metallic sound wheel bearings are suspect. If only moves in the horizonal grasp look at the bushings.


If something structural is suspected measure the inner sidewall or rim to wheelhouse distance directly above the axle line with the car flat on all fours. This can be done rough with a tape measure.

Jack the car up about 20 inches on one side enough to get both tires off the ground on the same side. If your car does not have much rear suspension travel (lowered) all the better because it will be bottomed forcing deflection making it easier to identify an issue. Check measurements again on the loaded side. What do you see?

Lower jack & repeat procedure for the other side and re-measure.

This will only provide a light loading but should identify if something is moving that shouldnt be.

If sheemetal is moving from fatigue or fracture (inner console ears) the measurement will close by a lot. You need to figure out what the lateral (sideways) movement is? From here you can get a trusted buddy to slowly raise the jack while your head is under the car focusing on the inner ear as you go from level (static) to load.

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Posts in this topic
yarin   Blew up another CV joint...   May 23 2008, 09:34 PM
Crazyhippy   I've put 400+HP through the Renegade Hybrids s...   May 23 2008, 11:48 PM
McMark   We definitely need some pictures and a postmortem ...   May 24 2008, 12:02 AM
Eric_Shea   Me too. :blink:   May 24 2008, 12:27 AM
Jeff Hail   Me too. :blink: Did you get your CV from tha...   May 24 2008, 12:30 AM
yarin   Me too. :blink: Did you get your CV from th...   May 24 2008, 07:32 AM
ericread   [quote name='Jeff Hail' post='1036159' date='May ...   May 24 2008, 11:22 AM
davep   Does that CV have the axle go to extreme angles a ...   May 24 2008, 07:42 AM
DNHunt   Yarin Sorry about the CV. What pressures are you ...   May 24 2008, 07:54 AM
yarin   Here are pics. The bearing race cracked, exact sam...   May 24 2008, 11:22 AM
yarin   The rear is pretty flat during cornering, suspensi...   May 24 2008, 11:26 AM
Eric_Shea   Mark and I had been investigating an incedent wh...   May 24 2008, 11:29 AM
Jeff Hail   Eric, I have been.... and priming,powdercoatin...   May 25 2008, 12:59 AM
Eric_Shea   Yes and No. Some cars still have their stock CV...   May 24 2008, 11:40 AM
yarin   Yes and No. Some cars still have their stock C...   May 24 2008, 11:44 AM
ericread   Yes and No. Some cars still have their stock C...   May 24 2008, 11:57 AM
Eric_Shea   These are areas of concern that I see: Looks like...   May 24 2008, 11:48 AM
yarin   Keep in mind that after the CV failed, it was flat...   May 24 2008, 11:57 AM
kwales   Couple of thoughts.. The beetle cv's don...   May 24 2008, 12:08 PM
Eric_Shea   We don't mfg. the joints. We machine 2 of t...   May 24 2008, 12:19 PM
Eric_Shea   That makes a ton of sense... forgot about that. ...   May 24 2008, 12:20 PM
brer   are those Lobro CV's you are using? if they a...   May 24 2008, 02:41 PM
davep   Is there any wheel hopping on the course? Somethin...   May 24 2008, 02:54 PM
yarin   Is there any wheel hopping on the course? Somethi...   May 24 2008, 03:26 PM
Eric_Shea   Those are German "Meyle" not EMPI. We c...   May 24 2008, 03:37 PM
brer   Meyle is a German company that does not produce th...   May 24 2008, 04:00 PM
Eric_Shea   I can switch to Lobro no problem if that's dee...   May 24 2008, 05:20 PM
Joe Ricard   I think the materails being used these days are no...   May 25 2008, 07:32 AM
davep   Being a physicist, I can understand what Jeff is t...   May 25 2008, 09:22 AM
Eric_Shea   Alright, alright... so you know everything! ...   May 25 2008, 12:31 PM
Jeff Hail   (anybody else hate this guy?) One more thing....   May 25 2008, 04:38 PM
ericread   (anybody else hate this guy?) One more thing...   May 25 2008, 08:50 PM
yarin   Thanks for all the info guys! Joe has put way ...   May 25 2008, 12:41 PM
kwales   Eric, CV joints are a lot like ball and roller be...   May 25 2008, 02:43 PM
Eric_Shea   :blink: Thanks Ken... I was just going off Jef...   May 25 2008, 02:49 PM
yarin   Hey Jeff, thanks for your in depth analysis.. but ...   May 25 2008, 05:59 PM
kwales   I don't hate Eric.... Anybody who does, is do...   May 25 2008, 07:08 PM
Eric_Shea   Thanks Ken :wub: But I think Jeff misplaced an ...   May 25 2008, 09:11 PM
yarin   All great points once again! How can I manuall...   May 25 2008, 10:41 PM
Jeff Hail   All great points once again! How can I manual...   May 26 2008, 01:28 AM
HAM Inc   Make sure the tranny is centered between the trail...   May 26 2008, 12:11 PM
yarin   Eric sent me a new CV no charge, got it a few days...   Jun 7 2008, 03:16 PM
yarin   more..   Jun 7 2008, 03:19 PM
yarin   Here is a quick video I shot illustrating the conc...   Jun 7 2008, 03:22 PM
kwales   All of mine slip on without pressing. That does l...   Jun 7 2008, 05:51 PM
yarin   The tranny mounts are the solid hard mounts, engin...   Jun 8 2008, 09:45 PM
yarin   Bump.. anyone care to share their CV installation ...   Jun 10 2008, 12:21 PM
racerx9146   I have a lifted Vanagon Syncro with 230 HP Subaru ...   Jun 10 2008, 05:37 PM
John   I was about to reply that mine typically slip onto...   Jun 10 2008, 02:47 PM
jhadler   Just thinking out loud here... Do you run on a pa...   Jun 10 2008, 06:26 PM
ericread   Just thinking out loud here... Do you run on a p...   Jun 11 2008, 08:42 AM
J P Stein   Like HAM I think there is something specific to yo...   Jun 11 2008, 10:55 AM


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