Front wheel bearing service, hub repair

R

robert gish

New member
Feb 18, 2016
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Right in the middle of servicing the front wheel bearings and when I pull the bearings off one of the hub's I find two large gouges either from a
previous catastrophic bearing failure or a catastrophic attempt at bearing removal. My question is what are the hub's made of and can they be welded?
I have a TIG machine and I'm sure I could fill the divots and turn the hub round again but are the hub's heat treated?
Also during this adventure I found a generic pulled in my toolbox that worked great for pulling the bearing stack off the hub without damaging the
bearings if anyone wants to get one like it I would be glad to share the information.
--
76 Eleganza mostly stock, Sully bags, needs one of everything.
 
> ...Also during this adventure I found a generic pulled in my toolbox that worked great for pulling the bearing stack off the hub without damaging
> the bearings if anyone wants to get one like it I would be glad to share the information.
Post a picture or two on the photo site with details.

http://www.gmcmhphotos.com/photos/
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"When I grow up I am going to be a curmudgeon."
 
> Right in the middle of servicing the front wheel bearings and when I pull the bearings off one of the hub's I find two large gouges either from a previous catastrophic bearing failure or a catastrophic attempt at bearing removal. My question is what are the hub's made of and can they be welded? I have a TIG machine and I'm sure I could fill the divots and turn the hub round again but are the hub's heat treated?

I can’t answer about touch-up TIG on the hubs - it may work or it may produce a localized undesirable effect. My hubs were beat up and needed attention so I cut down the diameter about 0.030 and had them built back up with spray welded stainless..following which I machined them back down to finish diameter. It has been a while since I did this but I do not remember them being particularly hard nor otherwise tough to machine such as if they were heat treated material.

See http://www.jcmco.com/gallery/album26 http://www.jcmco.com/gallery/album26 for a few pictures of it.

—Jim


Jim Miller
1977 Eleganza
1977 Royale
Hamilton, OH
 
> Right in the middle of servicing the front wheel bearings and when I pull the bearings off one of the hub's I find two large gouges either from a
> previous catastrophic bearing failure or a catastrophic attempt at bearing removal. My question is what are the hub's made of and can they be
> welded? I have a TIG machine and I'm sure I could fill the divots and turn the hub round again but are the hub's heat treated?
> Also during this adventure I found a generic pulled in my toolbox that worked great for pulling the bearing stack off the hub without damaging the
> bearings if anyone wants to get one like it I would be glad to share the information.

Hiwaystar,

Welcome to the group, family, cult, asylum...
I guess I miss noticing that you were new here a year ago and now I have some things to tell you.

First is that we have in the group (but seldom here) on Dave Lenzi. This man knows all about how to make the front bearings live. He is in the GMC
assist list (aka Black named for the originator). Call him. He can tell you anything you need to know.

Next, fill in you current sigfile with a real name so when you contact another owner there is a chance you will be recognized. This could matter more
than you expect because you are close to more than a few, but one you should know doesn't know where you are because he gets this forum as e-mail and
as such he does not see the Savannah in the header. You want to know this man. He is about 100 miles west and a veritable encyclopedia of GMC
knowledge.

If you have not yet hooked up with the Dixielanders, or Sunshine Statesmen do that as soon as you can. There are lots of reasons. If you did not
make the rally in Dothan last spring, just make to some rally before long so you can get to know other owners better.

If you have not figured it out already, this is a remarkable community. These are wonderful helping and supporting people that want to see you enjoy
what your coach can bring you. The level of support you can fine here is almost unbelievable. The only other community that I know of that is like
this is that of the waterme that are my world. They have a special way of welcoming a new owner or vessel that I sort of copy here because I enjoy
the sentiment. So,

May the Good Lord bless this coach and all those that set forth within here.

Welcome Robert

Matt

--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
The welding can cause enough shrinkage that the cvj may not fit the spline afterwards. I've had this happen on some Audi hubs that needed the same repair. I was able to open the splines with a small file and lots of patience.

Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)

>
> I played it safe. New greasable knuckles, and hubs from Mr. Lenzi,
>
> http://www.bdub.net/lenzi/#Hub
> --
> 77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy.
> Mid Michigan
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
My hubs were severely abused, undersized and gouged by someone with a torch.

Dave Lenzi was able to flame spray them back into being useable.

It aint cheap to flame spray and machine them but I did it, I should have gone 1 ton but I didn't know about them as they were extremely new at the time

If your's are as bad as mine, switch to the 1 ton.

________________________________
From: Gmclist on behalf of Les Burt
Sent: Thursday, February 16, 2017 8:30:55 AM
To: gmclist
Subject: Re: [GMCnet] Front wheel bearing service, hub repair

The welding can cause enough shrinkage that the cvj may not fit the spline afterwards. I've had this happen on some Audi hubs that needed the same repair. I was able to open the splines with a small file and lots of patience.

Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)

>
> I played it safe. New greasable knuckles, and hubs from Mr. Lenzi,
>
> http://www.bdub.net/lenzi/#Hub
> --
> 77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy.
> Mid Michigan
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
> I played it safe. New greasable knuckles, and hubs from Mr. Lenzi,
>
> http://www.bdub.net/lenzi/#Hub

I agree with this. Get the Lenzi knuckles and you will never have to take them apart again. IIRC the factory calls for greasing service every 25K
miles. To do this they must be taken apart, cleaned, inspected, and reassembled. A long two day process. Because of negative clearances, each time
you do this, the knuckles are damaged just a little. After several times doing this the bearing races are no longer a good fit, and knuckles have to
be replaced. By getting the "greasable" knuckles, every 25K miles, (I do it before every long trip) you only need to loosen the large axle nut, shove
the axle in, so that the inner seal is no longer making contact with the sealing surface, and apply grease to the zirk. Shoving the axle in as
described, allows grease to escape around the hub so that hydraulic pressure does not push the seal out of it's seat. I apply grease until the grease
coming out is as clean as the new grease going in. Put the nut back on the axle and tighten to spec'd torque. You're done. Lenzi knuckles come
complete, ready to install...no knuckle assembly required. The knuckles have a special spacer between the bearings that has been drilled and cut to
allow grease to pass evenly to the bearing surfaces. If your knuckles are in good shape you may be able, by borrowing the appropriate tools to take
them apart, drill and cut the spacer yourself, buy or borrow the drilling tool for the zirk and assemble the knuckle. FYI, Here is pics of the tool
and how to use it.

http://www.gmcmhphotos.com/photos/g5464-front-bearing-drill-fixture.html

Either way, buying or doing it yourself, set your knuckles up now while you've got them apart, and never have to take apart again. JWID

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
If you use Lenzi or our knuckle,
You will not need to grease them for 80,000 miles as the knuckle will hold
up
The reason for having to grease it every 20,000 is simply a worn knuckle
that allows the bearing assembly to wobble and not allow the seals to hold
the grease from coming out.
We are coming out with a special outter seal that will work well for those
with loose knuckles.
Allow us few weeks to get them. We will make them available to other GMC
shops.

> > I played it safe. New greasable knuckles, and hubs from Mr. Lenzi,
> >
> > http://www.bdub.net/lenzi/#Hub
>
>
> I agree with this. Get the Lenzi knuckles and you will never have to take
> them apart again. IIRC the factory calls for greasing service every 25K
> miles. To do this they must be taken apart, cleaned, inspected, and
> reassembled. A long two day process. Because of negative clearances, each
> time
> you do this, the knuckles are damaged just a little. After several times
> doing this the bearing races are no longer a good fit, and knuckles have to
> be replaced. By getting the "greasable" knuckles, every 25K miles, (I do
> it before every long trip) you only need to loosen the large axle nut,
> shove
> the axle in, so that the inner seal is no longer making contact with the
> sealing surface, and apply grease to the zirk. Shoving the axle in as
> described, allows grease to escape around the hub so that hydraulic
> pressure does not push the seal out of it's seat. I apply grease until the
> grease
> coming out is as clean as the new grease going in. Put the nut back on the
> axle and tighten to spec'd torque. You're done. Lenzi knuckles come
> complete, ready to install...no knuckle assembly required. The knuckles
> have a special spacer between the bearings that has been drilled and cut to
> allow grease to pass evenly to the bearing surfaces. If your knuckles are
> in good shape you may be able, by borrowing the appropriate tools to take
> them apart, drill and cut the spacer yourself, buy or borrow the drilling
> tool for the zirk and assemble the knuckle. FYI, Here is pics of the tool
> and how to use it.
>
> http://www.gmcmhphotos.com/photos/g5464-front-bearing-drill-fixture.html
>
> Either way, buying or doing it yourself, set your knuckles up now while
> you've got them apart, and never have to take apart again. JWID
>
>
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
G'day,

I found the following information on Gene Fisher's website and decided to
forward it to Dave Lenzi for verification:

Quote:

Here's some additional information that might be helpful.

Here are the hub/knuckle measurements from Cinnabar.

The hub diameter is supposed to be 2.0015 to 2.0025 with no steps or taper.
The bearing inside diameter is 2.000, that means the hub is 0.0015 to 0.0025
larger than the bearing resulting in a stiff press fit.

The knuckle diameter is supposed to be 3.2510 to 3.2525 with no more
than.0015 out of round. The average diameter must be within the 3.2510 -
3.2525 spec and the minimum diameter must be at least 3.2510. The bearing
size is 3.250, that means the knuckle is .0010 to .0025 larger than the
bearing. This is what my machinist calls an interference fit, it presses on
quite easily.

Charles Wersal

Unquote:

I received the following response from Dave:

Quote:

Rob,

This is NOT good information. I contacted Charles years ago to have him
change the dimensions of the knuckle. Obviously it did not happen.

The dimensions that Cinnabar is using came from an old GM drawing which I
have in my possession. This so called interference fit is actually a slip
fit (or what I like to call a SLOP fit).

Timken never did agree with this fit. GM insisted upon this loose fit so
owners/shops could service the bearings every 25,000 miles without removing
the knuckle from the coach. Their service manual shows the use of a slide
hammer to remove the hub, bearings from the coach, while leaving the knuckle
in place.

This fit, also utilized on every Toro and Eldo, is one of the reasons for
early bearing failures. The other reason is that the surface finish was very
poor. The single point tool (lathe) left ridges in the bore surface that
pounded out, only to make the bearing bore out of round and larger yet.

The correct fit for a Timken bearing in our knuckle is as follows. The bore
should be 3.2494 plus/minus .0002

This results in a light press fit of the outer race into the bore. A smaller
bore will dramatically reduce the pre established .009 clearance in the
bearing set by Timken.

My reworked knuckles are held to a much closer tolerance/surface finish than
ANY available today, because my knuckles are ground, not bored in a lathe.

PLEASE QUOTE ME, if you elect to post information on this subject.

Dave

Unquote

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of Robert
Gish
Sent: Thursday, February 16, 2017 2:18 PM
To: gmclist
Subject: [GMCnet] Front wheel bearing service, hub repair

Right in the middle of servicing the front wheel bearings and when I pull
the bearings off one of the hub's I find two large gouges either from a
previous catastrophic bearing failure or a catastrophic attempt at bearing
removal. My question is what are the hub's made of and can they be welded?
I have a TIG machine and I'm sure I could fill the divots and turn the hub
round again but are the hub's heat treated?
Also during this adventure I found a generic pulled in my toolbox that
worked great for pulling the bearing stack off the hub without damaging the
bearings if anyone wants to get one like it I would be glad to share the
information.
--
76 Eleganza mostly stock, Sully bags, needs one of everything.

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Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Thanks for all the helpful advice, especially the history lesson. Knowing the history of the design and the limits of the parts as they were designed
I have decided to go with the Chevy one ton conversion. It only makes since when you factor in the improvements and the cost.
Thanks again.

--
76 Eleganza mostly stock, Sully bags, needs one of everything.
 
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Applied GMC

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