Front Bearings

B

brent covey

New member
Jul 2, 1999
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Hi everyone- more silly questions here!

Anyone who has thier front hubs apart, or access to a parts catalog, could
you forward the front wheel bearing part numbers? Its stamped into them,
need the brand and number, thanks!!

Brent Covey
Vancouver BC
 
dont buy them using the part numbers they mean nothing for the GMC
motorhome, Order them from either cinnabar of Gateway, they know the GMC
motorhome and will send the correct ones. you need ones with .0095" of
axial clearance to be safe.

>
>Hi everyone- more silly questions here!
>
>Anyone who has thier front hubs apart, or access to a parts catalog, could
>you forward the front wheel bearing part numbers? Its stamped into them,
>need the brand and number, thanks!!
>
>Brent Covey
>Vancouver BC
>
>
>
 
Hi! thanks for the heads up-

My company sells Hyatt bearings, and I wanted to get one of our engineers
digging next time I speak with them to see if a similar or better quality
bearing exists in our catalogue to replace the factory installed (read cheap
as possible) units. Hoping to give them a head start on the job.

The caution is appreciated!

Brent Covey
Vancouver BC

>dont buy them using the part numbers they mean nothing for the GMC
>motorhome, Order them from either cinnabar or Gateway, they know the GMC
>motorhome and will send the correct ones. you need ones with .0095" of
>axial clearance to be safe.
 
Hi Brent,
I went back and got this info out of my file:

Subject:
RE: GMC: Wheel bearings
Date:
Wed, 21 Apr 1999 17:07:46 -0400 (EDT)
From:
"Thomas G. Warner"
Reply-To:
gmcmotorhome
To:
gmcmotorhome

Henry mine did not even come in a box, rather a plastic bag within a
plastic
bag, each part of the bearing wrapped in a oil impregnated brown paper.

Information on one of the bearings:
-Information on the inner race in order: Timken,.1209 (etched by
hand),LM104949E,+,USA AL.
- Information on outer race in order: TIMKEN-LM104911, USA, CD,
etched by hand 1205.
-Information on spacer in order: LM104911EA, .0095(etched by
hand),
.1205 (etched by hand)

Hope this helps.

>>Henry each bearing and race sold as suitable for the GMC should be etch
>>marked with a number. For example one of my new timken sets has on the
inner
>>race 1205 etched, and on the outer race the same number. The spacer has
>>etched in the outer edge .0095, which signifies that the bearing set has
>>.0095 of axial clearance when installed on the hub. Hope this helps.
>
>I didn't look for an etch number - just the outside of the box. Could you
>check your box for a P/N? Wes at Cinnabar was the one who told me that
>Timken didn't create a new P/N for the .0095 axial clearance sets. So, the
>boxes are marked with the plain P/N. Maybe there's another myth to kill
here.
>
>Henry
>
>Henry Davis Consulting, Inc / new product consulting
>PO Box 1270 / product readiness reviews
>Soquel, Ca 95073 / IP reviews
>ph: (831) 462-5199 / full service marketing
>fax: (831) 462-5198
>http://www.henry-davis.com/ http://www.henry-davis.com
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach

Hope this helps,
Skip Newhouse
'75 Avion in Western MD
 
Skip

Thats EXACTLY the info I needed.

This is by no means a special bearing. There are still a couple puzzling
questions, not least of which is why they would fail at low mileages!
Something is horribly amiss here- that bearing isnt working very hard at all
in a GMC. Its considerably understressed. I have some theories I'll bounce
off engineering.

Perhaps the press fit is too tight- the bearing and knuckle have a similar
coefficient of expansion, hence the interference fit should stay pretty
constant. However, material yeilds mean that the bearings cant possibly be
fitted at any greater interference fit than about 0.004" maximum. You
certainly could try, but in no time the materials would ease back to around
that anyhow. If they are installed much too tight in the beginning, and then
materials move and expand, there go the clearances!

Maybe EP 80-90 would be a better lube for these, it would permit preloading
the bearing with a crush sleeve instead of a spacer. No play! The reason
this has occured to me, is I am pretty sure one of those Part Numbers is a
pinion bearing in a GM differential...We sell little automatic lubricators
for things like sawmill machines, one could easily be adapted for this
purpose likely. Even a piece of narrow hose with a wick in it up to the
engine compartment might suffice..

0.0095 clearance IS a LOT. 0.002 is usual on similar bearings on rear
wheels. Typically 0.001"-0.006" is more usual.

Last but not least, I seriously wonder how it could be possible to mail
order a pair of bearings with a spacer withing five/tenTHOUSANDTHS of an
inch precision. That just cant be right!

Curiouser and curiouser. I'll get the smart guys to look at this for us,
they'll know!

Brent Covey
Vancouver

> -Information on the inner race in order: Timken,.1209 (etched by
>hand),LM104949E,+,USA AL.
> - Information on outer race in order: TIMKEN-LM104911, USA, CD,
>etched by hand 1205.
> -Information on spacer in order: LM104911EA, .0095(etched by
>hand),
>.1205 (etched by hand)
 
Dick,

The problem actually developed in the 80's as a result of a change in part
specification. The NDH bearings were being manufactured with too little
clearance. The original OEM's, if properly serviced, shouldn't be a
problem.

If you have the GMCMN backissues, read the bearing article. Very
informative, even if it's a little slanted toward the C'bar product.

Patrick

>
> Can someone clear up something for me?
> Have 75 PB with ORIGINAL OEM front bearings installed. I
> believe I read in
> one of these highly informative and periodically incindiary
> :-) posts that
> GM didn't discover a problem with the clearance on the
> original bearings
> until the 80s. If that IS true, it sounds like the wise
> thing for me is to
> pull the OEMs and replace with sets of Cinnabar .095 units.
> Do I have it right?
> Dick 75 PB in Atlanta
 
Can someone clear up something for me?
Have 75 PB with ORIGINAL OEM front bearings installed. I believe I read in
one of these highly informative and periodically incindiary :-) posts that
GM didn't discover a problem with the clearance on the original bearings
until the 80s. If that IS true, it sounds like the wise thing for me is to
pull the OEMs and replace with sets of Cinnabar .095 units. Do I have it right?
Dick 75 PB in Atlanta

>Hi Brent,
>I went back and got this info out of my file:
>
>Subject:
> RE: GMC: Wheel bearings
> Date:
> Wed, 21 Apr 1999 17:07:46 -0400 (EDT)
> From:
> "Thomas G. Warner"
> Reply-To:
> gmcmotorhome
> To:
> gmcmotorhome
>
>
>
>
>Henry mine did not even come in a box, rather a plastic bag within a
>plastic
>bag, each part of the bearing wrapped in a oil impregnated brown paper.
>
>Information on one of the bearings:
> -Information on the inner race in order: Timken,.1209 (etched by
>hand),LM104949E,+,USA AL.
> - Information on outer race in order: TIMKEN-LM104911, USA, CD,
>etched by hand 1205.
> -Information on spacer in order: LM104911EA, .0095(etched by
>hand),
>.1205 (etched by hand)
>
>Hope this helps.
>
>
>

>>>Henry each bearing and race sold as suitable for the GMC should be etch
>>>marked with a number. For example one of my new timken sets has on the
>inner
>>>race 1205 etched, and on the outer race the same number. The spacer has
>>>etched in the outer edge .0095, which signifies that the bearing set has
>>>.0095 of axial clearance when installed on the hub. Hope this helps.
>>
>>I didn't look for an etch number - just the outside of the box. Could you
>>check your box for a P/N? Wes at Cinnabar was the one who told me that
>>Timken didn't create a new P/N for the .0095 axial clearance sets. So, the
>>boxes are marked with the plain P/N. Maybe there's another myth to kill
>here.
>>
>>Henry
>>
>>Henry Davis Consulting, Inc / new product consulting
>>PO Box 1270 / product readiness reviews
>>Soquel, Ca 95073 / IP reviews
>>ph: (831) 462-5199 / full service marketing
>>fax: (831) 462-5198
>>http://www.henry-davis.com/ http://www.henry-davis.com
>>
>>
>>
>Tom & Marg Warner
>Vernon Center NY
>1976 palmbeach
>
>
>
>Hope this helps,
>Skip Newhouse
>'75 Avion in Western MD
>
>
 
Dick

I don't know if anybody answered your post, but, just to be on the safe side, I
would suggest replacing with a set from Cinnebar, but only if you can do it, or have
it done right. How many miles on your coach?

Wayne Newland F9300 75 Palm Beach Columbia, Md.

> Can someone clear up something for me?
> Have 75 PB with ORIGINAL OEM front bearings installed. I believe I read in
> one of these highly informative and periodically incindiary :-) posts that
> GM didn't discover a problem with the clearance on the original bearings
> until the 80s. If that IS true, it sounds like the wise thing for me is to
> pull the OEMs and replace with sets of Cinnabar .095 units. Do I have it right?
> Dick 75 PB in Atlanta
>

> >Hi Brent,
> >I went back and got this info out of my file:
> >
> >Subject:
> > RE: GMC: Wheel bearings
> > Date:
> > Wed, 21 Apr 1999 17:07:46 -0400 (EDT)
> > From:
> > "Thomas G. Warner"
> > Reply-To:
> > gmcmotorhome
> > To:
> > gmcmotorhome
> >
> >
> >
> >
> >Henry mine did not even come in a box, rather a plastic bag within a
> >plastic
> >bag, each part of the bearing wrapped in a oil impregnated brown paper.
> >
> >Information on one of the bearings:
> > -Information on the inner race in order: Timken,.1209 (etched by
> >hand),LM104949E,+,USA AL.
> > - Information on outer race in order: TIMKEN-LM104911, USA, CD,
> >etched by hand 1205.
> > -Information on spacer in order: LM104911EA, .0095(etched by
> >hand),
> >.1205 (etched by hand)
> >
> >Hope this helps.
> >
> >
> >

> >>>Henry each bearing and race sold as suitable for the GMC should be etch
> >>>marked with a number. For example one of my new timken sets has on the
> >inner
> >>>race 1205 etched, and on the outer race the same number. The spacer has
> >>>etched in the outer edge .0095, which signifies that the bearing set has
> >>>.0095 of axial clearance when installed on the hub. Hope this helps.
> >>
> >>I didn't look for an etch number - just the outside of the box. Could you
> >>check your box for a P/N? Wes at Cinnabar was the one who told me that
> >>Timken didn't create a new P/N for the .0095 axial clearance sets. So, the
> >>boxes are marked with the plain P/N. Maybe there's another myth to kill
> >here.
> >>
> >>Henry
> >>
> >>Henry Davis Consulting, Inc / new product consulting
> >>PO Box 1270 / product readiness reviews
> >>Soquel, Ca 95073 / IP reviews
> >>ph: (831) 462-5199 / full service marketing
> >>fax: (831) 462-5198
> >>http://www.henry-davis.com/ http://www.henry-davis.com
> >>
> >>
> >>
> >Tom & Marg Warner
> >Vernon Center NY
> >1976 palmbeach
> >
> >
> >
> >Hope this helps,
> >Skip Newhouse
> >'75 Avion in Western MD
> >
> >
 
>My company sells Hyatt bearings, and I wanted to get one of our engineers
>digging next time I speak with them to see if a similar or better quality
>bearing exists in our catalogue to replace the factory installed (read
cheap
>as possible) units.

I don't think the front wheel bearing problem is related to the quality of
the bearing. I think its more of an application problem. Given the fact
that the bearings seem to last indefinity if they are properly lubricated
every 25K miles (and not damaged in the process), I suspect the problem is
related to lubrication.

I don't know if the problem is the load on the bearing breaking down the
lubricant or if the problem is the grease not circulating enough to keep
the bearings lubricated. But it sounds like keeping good lubricant in the
bearing is probably the solution.

The challenge is to come up with a way to lubricate the bearings without
having to remove them from the knuckle. One idea that comes to mind would
be to use liquid gear grease rather than the semi-solid grease that we are
using now.

If we could find a place to add a couple of plugs to the knuckle. The upper
one would be a solid plug, the lower one would be for a grease fitting. To
change the fluid in the knuckle we would remove both plugs and the grease
would drain out the lower plug. To fill the knuckle we would insert the
lower plug (the grease fitting) and use a grease gun to inject the knuckle
with gear grease until it comes out of the upper hole. Then the plug would
be inserted in the upper hole.

If we did this procedure on a regular basis there would always be clean
gear grease in the knuckle. Gear grease is fluid enough to circulate and
keep the bearings lubricated. I know this sounds like a pain to do but its
not as painful as pulling and repacking the bearings every 25K miles.

The questions that come to my mind are:

- - Would gear grease be a good enough lubricant for the bearings?

- - Is there a location on the knuckle where the plugs would be accessible
without disassembling everything (or weakening the knuckle)?

- - Would the seals be good enough to retain the grease?

I don't have the answers but, if we could find the answers, it seems like
this could be a good solution.

Food for thought....

Dave
Ann Arbor, MI.
73 Sequoia (26'/455/EFI/HEI)
 
Dave No matter what modification we talk about it introduces trade offs.
Inject the grease at to high a pressure and you risk blowing a seal and
later contamination of the bearings.

I still think the best method is remove the hubs, replace the bearings and
seals, repack with mobil l. Total cost about $200. considering the number
of miles the average coach goes its a cheap semi-yearly expense. Would I
reuse a good bearing? Yes I would.

1

> >My company sells Hyatt bearings, and I wanted to get one of our engineers
> >digging next time I speak with them to see if a similar or better quality
> >bearing exists in our catalogue to replace the factory installed (read
>cheap
> >as possible) units.
>
>I don't think the front wheel bearing problem is related to the quality of
>the bearing. I think its more of an application problem. Given the fact
>that the bearings seem to last indefinity if they are properly lubricated
>every 25K miles (and not damaged in the process), I suspect the problem is
>related to lubrication.
>
>I don't know if the problem is the load on the bearing breaking down the
>lubricant or if the problem is the grease not circulating enough to keep
>the bearings lubricated. But it sounds like keeping good lubricant in the
>bearing is probably the solution.
>
>The challenge is to come up with a way to lubricate the bearings without
>having to remove them from the knuckle. One idea that comes to mind would
>be to use liquid gear grease rather than the semi-solid grease that we are
>using now.
>
>If we could find a place to add a couple of plugs to the knuckle. The upper
>one would be a solid plug, the lower one would be for a grease fitting. To
>change the fluid in the knuckle we would remove both plugs and the grease
>would drain out the lower plug. To fill the knuckle we would insert the
>lower plug (the grease fitting) and use a grease gun to inject the knuckle
>with gear grease until it comes out of the upper hole. Then the plug would
>be inserted in the upper hole.
>
>If we did this procedure on a regular basis there would always be clean
>gear grease in the knuckle. Gear grease is fluid enough to circulate and
>keep the bearings lubricated. I know this sounds like a pain to do but its
>not as painful as pulling and repacking the bearings every 25K miles.
>
>The questions that come to my mind are:
>
>- Would gear grease be a good enough lubricant for the bearings?
>
>- Is there a location on the knuckle where the plugs would be accessible
>without disassembling everything (or weakening the knuckle)?
>
>- Would the seals be good enough to retain the grease?
>
>I don't have the answers but, if we could find the answers, it seems like
>this could be a good solution.
>
>Food for thought....
>
>
>Dave
>Ann Arbor, MI.
>73 Sequoia (26'/455/EFI/HEI)
>
>
>
 
>
>Dave -- please clarify. Early in your message you say liquid gear
grease.
>By Gear Grease do you mean Gear Oil such as 90 weight?

That is what I was thinking. That is the lube used on many truck hubs. It
would be easy to drain from the hub after removeing the plugs.


Dave
Ann Arbor, MI.
73 Sequoia (26'/455/EFI/HEI)
 
>Dave No matter what modification we talk about it introduces trade offs.
>Inject the grease at to high a pressure and you risk blowing a seal and
>later contamination of the bearings.

That is why I was suggesting two plugs. One to inject the grease and the
other to release the air from the hub as the grease enters.

>I still think the best method is remove the hubs, replace the bearings and
>seals, repack with mobil l. Total cost about $200. considering the number
>of miles the average coach goes its a cheap semi-yearly expense. Would I
>reuse a good bearing? Yes I would.

I was just thinking that it would be nice if we could figure out an easier
way. Its a big production repacking the bearings. If we can lube them
without removing them, and that solves the problem, its a much better
solution.

Dave
Ann Arbor, MI.
73 Sequoia (26'/455/EFI/HEI)
 
>
> There should be someone out there on the Net that is familiar with the
> liquid-grease bearing setup that Walter Wallace was running on his GMC type
> strech MH (sightglass on the Hub like the big Trucks use)

I can't help, but the coach parked behind Jim Bounds at Marion had this
setup. Ken Thoma came by to chat and we talked about that setup. He
was familiar with it and who had developed it. Ken would probably be a
good place to start.

Patrick
- --
Patrick Flowers
Mailto:patrick

The GMC Motorhome Page
http://www.gmcmotorhome.com
 
>
> If we could find a place to add a couple of plugs to the knuckle. The upper
> one would be a solid plug, the lower one would be for a grease fitting. To
> change the fluid in the knuckle we would remove both plugs and the grease
> would drain out the lower plug. To fill the knuckle we would insert the
> lower plug (the grease fitting) and use a grease gun to inject the knuckle
> with gear grease until it comes out of the upper hole. Then the plug would
> be inserted in the upper hole.

Discussed this very thing with Ken Thoma at Marion.

> - Would the seals be good enough to retain the grease?

According to Ken, this is the problem. The inner seal(the same one
that's likely to blow out if you install a zerk) won't handle oil. Now
if you could come up with a better seal...

Still, don't think I'd want my coach to be the guinea pig on this one.
If that inner seal leaks, the oil goes straight to the brake rotor and
all over the front wheels. Not my idea of fun.

Patrick
- --
Patrick Flowers
Mailto:patrick

The GMC Motorhome Page
http://www.gmcmotorhome.com
 
Patrick,

The liquid bearing set up we salivated at in Marion was on the rear wheels
& we really wanted to see something like that for the front. Leigh
Harrison said he though he could look into it.

Since then, I had a customer call asking for parts for one of the systems
that was on his coach. I asked him where he got it but it was on the coach
when he dot it.

I still feel you would have mush less bearing friction & trouble with a set
up like that. Anybody out there know about the set up?

Jim Bounds
- ----------------------

>>
>> There should be someone out there on the Net that is familiar with the
>> liquid-grease bearing setup that Walter Wallace was running on his GMC type
>> strech MH (sightglass on the Hub like the big Trucks use)
>
>I can't help, but the coach parked behind Jim Bounds at Marion had this
>setup. Ken Thoma came by to chat and we talked about that setup. He
>was familiar with it and who had developed it. Ken would probably be a
>good place to start.
>
>Patrick
>--
>Patrick Flowers
>Mailto:patrick
>
>The GMC Motorhome Page
>http://www.gmcmotorhome.com
>
>
 
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