| Rear Bearings/Grease Seal: [message #216351] |
Tue, 30 July 2013 23:04  |
noi
Messages: 293
Registered: October 2010
Location: South of Fremont
Karma: 0
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Greetings,
I am just about ready to pack the rear bearings and reinstall the hubs on the spindles - But I am a bit confused, yah doesn't take much, about the rear grease seal seating criteria.
The Assembly Manual, page 512, states the grease seals should be seated to within .025/.045 high of flush - Though how in the heck that would be done is beyond me.
I searched all the years M/M's and did not find any information in regards to rear wheel bearing packing or grease seal seating - Or my eyes glazed over and I just missed it!
And from many years ago in HS shop, I remember that the grease seals were just tapped in till "flush" with the hub.
So.... I don't have any tiebreaker information - Therefore:
Looking for any thoughts/ideas as to why the A/M would say one thing and/or the M/M's say nothing.
Thanks for any insight you can/care to share,
Carl P.
76 Birchaven
South of Fremont
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| Re: Rear Bearings/Grease Seal: [message #216355 is a reply to message #216351] |
Tue, 30 July 2013 23:32  |
Otterwan
Messages: 946
Registered: July 2013
Location: Lynnwood (north of Seattl...
Karma: 0
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I'm no pro, but I've done a lot of wheel bearings on 60's and 70's vehicles, as well as trailers, and I've always seated the seals by laying a 2" x 4" across the hub and tapping the seal as far as it will go. I think the softness of the wood gives you the exact 0.025" - 0.045" range you are looking for ;o)
I would rack this sort of spec up to the same reason as torque specs for spark plugs. Anyone here every actually torque a spark plug? Anyone?
1977 Birchaven, Lynnwood WA - "We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us."
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| Re: Rear Bearings/Grease Seal: [message #216371 is a reply to message #216355] |
Wed, 31 July 2013 08:04 |
bobby5832708
Messages: 237
Registered: November 2006
Location: Winter Springs FL
Karma: 3
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Senior Member |
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I've always torqued spark plugs on my cars. One of my current cars, a Ford 4.6, the proper plug torque is critical so the aluminum heads don't strip out. I've been taught that even on cast iron heads the plugs have to be tightened properly as it affects the heat range due to the ability (or lack of it) to transfer heat from the plug to the head.
I guess since I learned to use a torque wrench at an early age when working on a VW aluminum head engine I may as well use the torque wrench on everything. If you look in the manual everything has a torque spec. I feel that if the engineers who designed the product give actual tightness values to tighten things to then why not follow their specs -- those engineers are smarter than me, why try to second-guess them.
JWID.
Bob Heller
2017 Winnebago 29VE
Winter Springs FL
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| Re: Rear Bearings/Grease Seal: [message #216389 is a reply to message #216351] |
Wed, 31 July 2013 11:21 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Another case of bad offshore junk. Best to go with our vendors who have already gone to school on companies' mistakes for us.
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Rear Bearings/Grease Seal: [message #216396 is a reply to message #216384] |
Wed, 31 July 2013 11:59 |
Otterwan
Messages: 946
Registered: July 2013
Location: Lynnwood (north of Seattl...
Karma: 0
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| noi wrote on Wed, 31 July 2013 08:56 |
Otterwan – Thanks for the thoughts – Did see a few youtube demos where people used a 2x4 – And yes, do in fact torque spark plugs.
Bob – I’m with you on use torque wrench for everything with a stated torque!
Bruce/Rob:
Thanks for the reminder about seal clearance – I did remember all the discussion / pictures / testing some time back about that – No problems there though, as I got the proper seals from JimK.
But to clarify/focus the question – If using the correct seal, with correct clearance, why would the assembly manual state that the seal is not set flush to the hub and no where else can I find that requirement.
Carl P.
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I do torque things like lug nuts and head bolts, and yes, I admit it, I have torqued plugs going into aluminum heads. But not plugs in cast iron heads, and never had a problem.
I assume that with a disc brake conversion this issue becomes moot, no? Also, has anyone ever tried oil bath hubs on a GMC? I have them on a boat trailer, and they are awesome! Had the boat for several years and never had to touch the bearings.
1977 Birchaven, Lynnwood WA - "We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us."
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| Re: [GMCnet] Rear Bearings/Grease Seal: [message #216405 is a reply to message #216382] |
Wed, 31 July 2013 13:05 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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| WD0AFQ wrote on Wed, 31 July 2013 11:48 |
I bought all of the USA seals I could find, for spares, after I measured them to make sure they are the right ones.
Dang, I should have torqued my vdub plugs. Number 3 would Might not have blown out if I had. 
Dan
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(Editted by Matt)
Dan,
Installing a spark plug to torque is only half the problem and less than half in any alloy cylinder head....
If you are going to change plugs, have some nickel based (sensor safe) anti-sieze on hand. Carefully coat each plug. What kills alloy heads is that the aluminum alloy welds to the spark plug body and gets ripped loose when the plug is removed. The reason to tighten a spark plug is to set the crush on the metal gasket. The Champion book used to carefully stipulate that the way to seat a gasketed plug was to tighten it with just fingers on the socket or extension until the gasket was solid on the seating face and then turn another 90°. This was much better, than torque because the load on the gasket was independent of the thread quality. We got push to this (this testing was all done in my lab at McCord gasket - now a part of Federal Mogal - like Champion) because we made the gaskets for them. (Several cubic yards of them a day.)
Warranty found out that nobody understood the simple directions....
So, they only published one guide with this procedure.
Spark plug siezure is even more of a problem now that plugs don't get changed out ever 5~10K, but with a 50K plug, it can really get cooked in there.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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