I'll be doing some general rambling, ranting and perhaps some raving here. Not sure if it'll be of any interest but we'll give it a shot. If you have comments, good or bad, please email them to me at firstname.lastname@example.org.
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Shortcuts to topics: Front Bearings
September 5, 1999: Re-seating rear bearings.
Learned a bunch of new stuff this week, thanks to GMCnet and the Internet as a whole. While I installed my replacement Alcoas, actually as I was almost finished, I noticed and ever so slight amount of play in the bearings. This play was noticed when the tire was grabbed firmly and moved to the inside/outside.
About the same time some traffic came across GMCnet that led me to the Timken site's Tech Section. It noted that bearings should be seated at 200 pounds and reseated at 50 pounds of torque.
Recalling how the rear bearing had been installed by so-called experts I decided to "redo" them, sort of. I usually try and watch what is done to my coach so I observed several bearing changes over the years. It's always been just a tighten with a big pump pliers and back it off enough to get the cotter pin in. As it had always been done in shops prior to my building my own garage I naturally assumed that was the correct way.
Well... I certainly found out differently courtesy of the Timken website.
So... I took all the rear wheels off again so that I could remove the grease caps without damaging the new shiny's (Alcoas).
I then tightened the retaining nut while turning the wheel until it turned no more. I'm sure it was less than 200 pounds, but I figured it was better than past "seatings" of the bearings.
I then loosened the nut a full turn or so, and retightened it (while rotating the wheel) to 50 pounds and then backed off the nut until I had the hole lined up for the cotter pin which was usually close to the recommended 1/6th of a turn.
The play is gone and the wheel still turns nice and easy. Only time and miles will tell if this was a good preventive move or not :-)
I did not use a dial gauge this time as I have to figure out how to set it up and use it. Maybe next time.
Front bearings have been a hot and heavy topic of late on the GMCnet. When a post was made as to how the GMC got it's bad rep I tried to interject a little lighthearted humor and a following reply caused me to make my own experiences known. Perhaps I've just been lucky and if so I hope it keeps up .
When I took my coach for it's first alignment in the 80's the shop told me that the front bearings should be done, and done first. They recommended a local shop and off I went.
The end result was front bearing assemblies that include a grease fitting on each steering knuckle. I was instructed to put a grease gun to the fittings every 5-10 thousand miles and not to squeeze hard but rather a gentle press on the lever.
What I did is purchase a small grease gun, perhaps tiny is a better description of its size. I filled it with wheel bearing grease and used it as instructed. I used the pressure I could muster with thumb and forefinger only as maximum. In general I can feel when a void is being filled, i.e. not really adding grease under pressure but perhaps just replacing grease that evaporated or perhaps it's just making up for a not quite right packing procedure.
As this was first done during pre-Cinnebar days I'm quite sure (yet not positive) they were stock bearings, obtained locally. I had the same shop replace them years later with about 75,000 miles on them and again a couple of years ago by a Truck Shop in Quebec City on our way back from our East Coast Vacation, again many miles later.
I'm still running the same assembly, as the grease fittings still exist. During my last couple of checks one side took a little grease one time and none the next and the last check neither took any. I used to pack the little grease gun along and do it enroute when we were traveling heavily but since I now travel solo much of the time I find myself home more often and hence servicing usually gets done at homebase :-).
I really need to stress that no to very little pressure is applied to the grease gun lever.
Unfortunately I can't tell you specifically how/what was done when the grease fittings were added as that was done during a time when knew very little (nothing) about my newly acquired GMC and was totally dependent on the goodness of the shop keepers. Of course that was still during times when you could put your trust into the shop keeper and his ethics.
I'm please to say that all bearing changes in the past were done on a "drive in" basis. I expect that it'll still be quite a few more miles before the next change is required. This time I'll be ready for an "in house" experience. Perhaps I'll be able to supply more information re my particular setup during that next change, but please don't hold your breath as I hope that'll be more than a year away.
Hopefully I have not applied a hex by attempting to share .
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