Date: Thu, 9 Mar 2006 10:51:13 -0600
Reply-To: John Rodgers <inua@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@CHARTER.NET>
Subject: Re: need input on confusing CV joints...
In-Reply-To: <001d01c6438b$d80291c0$6900000a@SNOWTRAILS.COM>
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From my reading and study about the rebuilt CV's - often used in
"complete axle assemblies" at low prices which make them so attractive -
the CV's are drilled, reamed, machined, and then over-sized ball
bearings put in.
The CV's were engineered with specific specs and the installation of
those specified parts was also engineered to operate in certain
parameters and provide certain performance. . The CV's are close
tolerance parts, and the minute the dimensions are altered, the geometry
of operations changes and the loads on the part are then different. I
contend that it results in different performance with different wear
patterns, none of which equals or increases the longevity of the parts.
I'm also suspicious of the the hardness of the surfaces of the bearings
and the races. Given the place that a CV serves in, and the kind of
loads placed on it, I think that new bearing races particularly have
been specially hardened to stand up to the wear. The process is most
likely a nitriding process which is often used to harden surfaces for
better wear and longer life. Crankshaft bearing surfaces are a good
example. . If that surface is machined in any way, and not put back
through the nitride process the surface hardness is lost, and wear will
be much more rapid. That, plus the changed geometry, will result in a
much shorter life of the part. Of course this is educated conjecture on
my part, but it seems logical.
All that being said, if bucks are in short supply, go for the cheaper
parts, just be aware that the life will be shorter, and you will be
replacing them much sooner. Don't bitch about poor parts when it happens.
As for improper assembly, yes, they can be re-assembled incorrectly
after cleaning. They will not flex properly when that happens. I doubt
that an axle with both CV's improperly assembled can actually be
installed that way. I haven't run across the problem, but I do question
it. Anybody??
My question is - Is there a front and a back to a CV. All I have ever
worked with came with a groove in the outside of the race, on one side.
I always made sure that groove was in the same direction as when the CV
came off the shaft. However, that still doesn't mean it is correct. What
if the PO had done it wrong?? What then? Just wondering.
Regards,
John Rodgers
88 GL Driver
carboncow wrote:
>I agree Bill. If assembled wrong it's frozen, from what I can tell there are
>only two options. Correct and working and frozen. If you assemble the
>bearings and the outer ring through the backside it will lock up.
>
> I'm guessing there is just a flaw in the low quality unit since this was a
>replacement that had the click.
>
>Shawn
>
>-----Original Message-----
>From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>Bill Collins
>Sent: Thursday, March 09, 2006 10:01 AM
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: need input on confusing CV joints...
>
>
>
>>Sometimes CV joints get assembled improperly. Look at the right up on
>>Tom Carrington's web page and the pictures. He explains in detail how
>>to reassemble them correctly and incorrectly. It is not unheard of to
>>find that a joint was assembled incorrectly when they are rebuilt.
>>This could be the case. So perhaps you can reassemble it and have a
>>good spare axle.
>>
>>
>
>I thought an incorrectly assembled joints is completely locked up and can't
>even be installed on the van.
>
>The only joints I have ever had fail while the boots were intact were on
>cheap FLAPS re-built axles.
>
>Bill
>
>
>
>
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