Date: Thu, 9 Mar 2006 12:22:26 -0500
Reply-To: carboncow <feller@CARBONCOW.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: carboncow <feller@CARBONCOW.COM>
Subject: Re: need input on confusing CV joints...
In-Reply-To: <44105D01.4060608@charter.net>
Content-Type: text/plain; charset="us-ascii"
I would agree with this statement about tolerance on rebuilds. The unit that
came out was a replacement from before with oversized bearing balls. The new
unit I put in (two new CV and axle) had smaller balls. Interesting how
easily the ball fell out of the old one (obviously parts have wear) while
the new CV had balls that fit into the ring with a nice "snap".
On my new CV/axle I took one of the CV assemblies off trying to put it back
together (it fell part while greasing the other end!) and noted that there
was a flange cut on the CV assembly that should butt up against the axle
stop. This a "correct way" to reassemble it. They were unique although I
don't know if this really affects if the CV has a "correct way" to be on.
Shawn
-----Original Message-----
From: John Rodgers [mailto:inua@charter.net]
Sent: Thursday, March 09, 2006 11:51 AM
To: carboncow
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: need input on confusing CV joints...
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
>
>
>
>
