Hubs $125

bartz paul

New member
Dec 3, 1997
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Pat:

I replaced my bearings in Aug 1996 and got knuckles from a GMCer
machinist (price was right) that were sleeved with harder tubing.

Paul

> -----Original Message-----
> From: Mike Finnicum [SMTP:mike]
> Sent: Thursday, July 09, 1998 3:56 PM
> To: gmcmotorhome
> Subject: Re: GMC: Hubs $125
>
> I just replaced a right hub. I got it from Alex for $125. He usually
> has some in stock. I have to assume it was reconditioned, I did not
> ask. My guess is that he would also have knuckles. 941-763-1121.
>
>
> As I described in another post, I got the bearings off last night and,
> as I feared, the right side hub and knuckle are shot. It's obvious
> that it spun a bearing at some time, because someone "staked" the
> inside of the knuckle to get it to hold the bearing.
>
> In the GMCMI newsletters it says that Ken Thoma reconditions hubs and
> knuckles for $150 and $125 respectively. Does anyone know how much
> new ones are? Does anyone have any experience with the reconditioned
> ones?
>
> Patrick
>
 
>
> I replaced my bearings in Aug 1996 and got knuckles from a GMCer
> machinist (price was right) that were sleeved with harder tubing.

Paul,

If you can find it, please pass along the name, phone number and the
price(probably increased by now).

I forgot to mention earlier that my bearings looked in pretty good
shape(a pleasant surprise). I'm gonna clean them up, check the
clearance(now that I know how) and keep them for spares.

Patrick
- --
Patrick Flowers
Mailto:patri63

The GMC Motorhome Page
http://www.gmcmotorhome.com
 
I just replaced a right hub. I got it from Alex for $125. He usually
has some in stock. I have to assume is was reconditioned, I did not
ask. My guess is that he would also have knuckles. 941-763-1121.

Mike Finnicum
78 GMC Eleganza II
Naples, FL

>As I described in another post, I got the bearings off last night and,
>as I feared, the right side hub and knuckle are shot. It's obvious that
>it spun a bearing at some time, because someone "staked" the inside of
>the knuckle to get it to hold the bearing.
>
>In the GMCMI newsletters it says that Ken Thoma reconditions hubs and
>knuckles for $150 and $125 respectively. Does anyone know how much new
>ones are? Does anyone have any experience with the reconditioned ones?
>
>Patrick
>--
>Patrick Flowers
>Mailto:patri63
>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
 
Patrick.......Just for the record, any decent bearing supply house sells
sleeves that slide over a ruined length of shafting. Some of them can be
used without machining and require a bearing with a larger ID. Some require
that the shaft be machined down. I've used a few over the years..........Jim
Davis
- -----Original Message-----
From: Patrick Flowers
To: gmcmotorhome
Date: Thursday, July 09, 1998 11:59 AM
Subject: Re: GMC: Hubs $125

>>
>> I replaced my bearings in Aug 1996 and got knuckles from a GMCer
>> machinist (price was right) that were sleeved with harder tubing.
>
>Paul,
>
>If you can find it, please pass along the name, phone number and the
>price(probably increased by now).
>
>
>I forgot to mention earlier that my bearings looked in pretty good
>shape(a pleasant surprise). I'm gonna clean them up, check the
>clearance(now that I know how) and keep them for spares.
>
>Patrick
>--
>Patrick Flowers
>Mailto:patri63
>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
>
 
I am interested patrick how you were told to check the clearances?

>>
>> I replaced my bearings in Aug 1996 and got knuckles from a GMCer
>> machinist (price was right) that were sleeved with harder tubing.
>
>Paul,
>
>If you can find it, please pass along the name, phone number and the
>price(probably increased by now).
>
>
>I forgot to mention earlier that my bearings looked in pretty good
>shape(a pleasant surprise). I'm gonna clean them up, check the
>clearance(now that I know how) and keep them for spares.
>
>Patrick
>--
>Patrick Flowers
>Mailto:patri63
>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
>
>
 
>
> I am interested patrick how you were told to check the clearances?

I'll put it on the site with pictures when I can get to it, but I'll try
to describe it here. You place a tube(Ken used a cardboard tube, like a
toilet tissue roll - I'm gonna' make one out of pvc pipe)inside the
bearing set just long enough to hold the bearings and spacer in
position. Then put the bearing set in a vise and tighten until it's
just snug. Take two feeler gauges of the same thickness(according to
Wes Caughlin three is better(GMC Motorhome News 9/96 pg. 3)) and insert
them between one of the outer races and the spacer on opposite sides
radially of the assembly. What you're trying to do is measure the total
clearance between the outer races and the spacer. The two feeler gauges
make the spacer parallel - three are like a tripod, more stable. The
assembly needs to be clean and dry for this measurement - no grease.

I hope that's clear - pictures are worth many thousand words.
Patrick
- --
Patrick Flowers
Mailto:patri63

The GMC Motorhome Page
http://www.gmcmotorhome.com
 
Sounds good what is the clearance?

>>
>> I am interested patrick how you were told to check the clearances?
>
>I'll put it on the site with pictures when I can get to it, but I'll try
>to describe it here. You place a tube(Ken used a cardboard tube, like a
>toilet tissue roll - I'm gonna' make one out of pvc pipe)inside the
>bearing set just long enough to hold the bearings and spacer in
>position. Then put the bearing set in a vise and tighten until it's
>just snug. Take two feeler gauges of the same thickness(according to
>Wes Caughlin three is better(GMC Motorhome News 9/96 pg. 3)) and insert
>them between one of the outer races and the spacer on opposite sides
>radially of the assembly. What you're trying to do is measure the total
>clearance between the outer races and the spacer. The two feeler gauges
>make the spacer parallel - three are like a tripod, more stable. The
>assembly needs to be clean and dry for this measurement - no grease.
>
>I hope that's clear - pictures are worth many thousand words.
>Patrick
>--
>Patrick Flowers
>Mailto:patri63
>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
>
>
>
 
>
> Sounds good what is the clearance?

Good question! I would love to hear some discussion of that one.
According to Wes Caughlin in the 6/96 issue of GMC Motorhome News, .0095
is the minimum and the bearings that Timken produces for Cinnabar (Part
No. 12351677) are set at that clearance. The Timken set that Ken
installed in his video was set at .006, which, according to Wes, is too
little clearance. In the same article, Wes said "In fact, tests have
shown that when a bearing set with a small inside diameter(that is
within tolerance) is pressed on a large GMC Motorhome hub(that is within
tolerance), up to 0.007 inches of unassembled axial clearance will
disappear. Since 0.002 to 0.003 inches of assembled axial clearance has
been found to be the absolute minimum required for the GMC Motorhome
application, a bearing with less than 0.0095 unassembled axial clearance
is not suitable." Note the distinction between assembled and
unassembled axial clearance. What you measure in the vise is
unassembled axial clearance.

Anyone care to step in the middle of this mess?
Patrick
- --
Patrick Flowers
Mailto:patri63

The GMC Motorhome Page
http://www.gmcmotorhome.com
 
that is the same info I received and it makes sense. If you mike all of the
surfaces and know how to calculate the assembled clearances than you can use
less than .095. The point is why take a chance? I received the correct
Timken bearings and seals from gateway for $77. each, less than I could have
bought the Timken bearings alone for locally.

I have a strong feeling that this failure to take these assembled clearances
into account is the cause of some of the catastrophic failures we hear so
much about, along with spun bearings etc. REmember that every part, hub,
bearing, knuckles have minimum and manximum tolerances for each part. If the
hub is oversize, the inside of the bearing undersize, and the knuckle
undersize, one could have a worse case assembly with the most amount of
compression of the parts. Could spell disaster.

>>
>> Sounds good what is the clearance?
>
>Good question! I would love to hear some discussion of that one.
>According to Wes Caughlin in the 6/96 issue of GMC Motorhome News, .0095
>is the minimum and the bearings that Timken produces for Cinnabar (Part
>No. 12351677) are set at that clearance. The Timken set that Ken
>installed in his video was set at .006, which, according to Wes, is too
>little clearance. In the same article, Wes said "In fact, tests have
>shown that when a bearing set with a small inside diameter(that is
>within tolerance) is pressed on a large GMC Motorhome hub(that is within
>tolerance), up to 0.007 inches of unassembled axial clearance will
>disappear. Since 0.002 to 0.003 inches of assembled axial clearance has
>been found to be the absolute minimum required for the GMC Motorhome
>application, a bearing with less than 0.0095 unassembled axial clearance
>is not suitable." Note the distinction between assembled and
>unassembled axial clearance. What you measure in the vise is
>unassembled axial clearance.
>
>Anyone care to step in the middle of this mess?
>Patrick
>--
>Patrick Flowers
>Mailto:patri63
>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
>
>