Date: Sat, 4 Dec 2004 10:51:20 -0500
Reply-To: Dennis Haynes <dhaynes@OPTONLINE.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <dhaynes@OPTONLINE.NET>
Subject: Re: Knocking noise
In-Reply-To: <41B1C8D5.501@charter.net>
Content-type: text/plain; charset=US-ASCII
CV joint wear has nothing to do with direction of rotation. The wear is
caused by the transfer of torque. The trans side transfers torque from
the outer flange to inner shaft. The wheel side is reversed. Turning the
shaft 180 degrees will still reverse the direction but also the
direction of torque transfer so still, only one side of the ball grooves
will get used. You need to swap sides.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of John Rodgers
Sent: Saturday, December 04, 2004 9:25 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Knocking noise
Al Brase and Dennis Haynes have been kind enough to express differing
opinions on this so in response here is further explanation from my
point of view for benefit of The List Membership.
My perception of this is that we are talking principally about the goal
of changing the direction of rotation of the bearing and axle when we
speak of swapping them to opposite sides of the vehicle. This is to take
advantage of changing the wear pattern on the bearings to extend the
life of the bearings.
It is an easy thing to swap them to opposite sides of the vehicle - and
miss changing the direction of rotation!!
This is why I suggest keeping the shafts on the same side of the vehicle
as it is easy to induce confusion.
Imagine pulling the right hand shaft assembly and holding it in the
middle with your right hand, much the way you would hold a dumb-bell
when working out. . Now rotate the your wrist so that the shaft rotates
end to end 180 degrees, swapping relative positions with the bearings.
Now, re-install the shaft assembly on the same side of the vehicle, and
the bearings and axle will rotate in the opposite direction when in
operation. There is nothing to prevent you from installing it on the
opposite side of the vehicle, as long as you swap ends as I have just
described. To me it is just easier to do one side at a time and avoid
confusion.
It has been a while since I changed mine, so I used an old CD with a
circular arrow drawn clockwise on it to test this and refresh myself.
When the CD was held so it's thinnest plane was perpendicular to the
floor, and a pencil stuck through the hole horizontally, and the CD
rotated over the top away from me, the arrow appeared to move clockwise
traveling in the direction the arrow pointed. When the CD was flipped
over, as if it were a CV on the axle, and again rotated over the top
away from me, the arrow then traveled backward. This proved my point to
myself. Flip the shaft assembly end to end and you change the direction
of rotation of the shaft and bearings.
Another way to check this is to use an old DC electrical concept.
Fingers point in the direction of the magnetic field, thumb points in
the direction of the current flow. But in this case, fingers point in
direction of rotation, thumb points to the shaft end next to the trans
mission. Grasp the axle shaft over the top with the right hand, again
like picking up a dumb bell. With the thumb pointing in the direction of
the transmission, and the fingers curled over the top of the axle, note
the direction the finger are curving - pointing down. . This is
direction of rotation. Now flip the shaft so the thumb points in the
opposite direction. Note that now the fingers are curled in the opposite
direction - pointing up. This represents the change in the direction of
rotation as a result of swapping ends of the axle with the bearings on
it. Once flipped this way, the axle can be properly installed for best
advantage either on the side it was removed from or the opposite side of
the vehicle. I personally do it on the same side, one axle at a time to
avoid confusion.
Again, if you flip the shaft 180 degrees end to end, and re-install,
either on the same side or opposite sides of the vehicle, the effect is
the same. I just believe it is easier to avoid a mix-up if done one
shaft at a time. Why?? If you fail to flip the shaft 180 degrees, you
will not get the advantage of the change in rotation. It's much the same
as changing the right rear tire and putting it on the left rear. In this
case, the tire and rim are flipped on the vehicle, so the wheel rotates
in the opposite direction than when it was on the right rear, thus
changing the wear pattern, which is the goal in swapping ends with the
the axle assembly.
If the bearings are to be removed from the shaft, for cleaning and
servicing first, then you COULD just swap the bearings on the shaft ends
and accomplish the same goal with out literally swapping the shaft ends
180 degrees.
This whole shaft/bearing thing can get confusing. BTDT!!!!!
If I have missed something about this, let me know, will you. I
certainly don't want to put out wrongful or incomplete information.
Thanks,
Regards,
John Rodgers
88 GL Driver
John Rodgers wrote:
> You need to be careful in this swapping sides business.
>
> I hope I can explain this clearly enough that it can be understood.
>
> The simplest way is to swap the axle position on the same side. In
> other words, put the outboard end of the shaft - the on in the box -
> next to the tranny, and the tranny end to the out board position in
the
> box. Do one axle at a time, and avoid any confusion. What this swap
> will do is reverse the direction of rotation of the axle and bearing
so
> the wear points are a bit different. Do one axle at a time, and avoid
> any confusion.
>
> It's not necessary to swap to opposite sides of the vehicle. That
easily
> induces confusion.
>
> Regards,
>
> John Rodgers
> 88 GL Driver
>
>
>
>
> Al and Sue Brase wrote:
>
>> AND, if you've not done this before, and other cv's need service, do
all
>> four and put the right axle on the left and the left axle on the
>> right.(only with manuals, the automatic axles are different lengths.)
>> This puts the wear areas on a different place and could give your
cv's
>> several more years of life
>> Al Brase
>>
>> jimt wrote:
>>
>>>>
>>>>
>>> With it only at the slower speeds, I would drop that cv and see if
>>> maybe it
>>> is dry and just needs a repack. Wipe down the balls and see if
there
>>> is any
>>> major pitting and also check the carriers for damage as well. If
>>> there is
>>> replace joint/axel.
>>>
>>> http://www.westydriver.com
>>>
>>>
>>>
>>
>>
>
>
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