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wheel bearing replacement

Posted: Thu Aug 12, 2010 8:51 pm
by impinnacr
Here's a good story: I took my trailer to a local boat bechanic a few weeks ago. He repacked the bearings and replaced a worn inner seal on one of the hubs. I trailered the boat on tuesday about 80 miles. when I got to my destination at Folsmon lake, I placed the boat in the water, parked the truck and trailer, and went sailing. when I got back, I noticed that the bearing buddy on one of the wheels was gone! In addition, the grease was essentially gone. I could see roller bearings clearly exposed. Great, I figured it probalby fell off on the highway somewhere. I didn't notice it when putting the boat in the water, etc. I did remember seeing the b/b when I did a walk around prior to leaving that morning.
OK, off I went to West Marine on Micron ave. in Sacto. I puchased a new bearing buddy, a grease gun and extra grease cartridges. I got back to the marina, used the mallet and a weed block to reset the bearing buddy and filled the hub with grease. I drove 20 miles and checked the hub. It wasn't hot. Basically, I drove 20 mi and stopped to check the hub for heat and wound up topping off the grease twice. I made it back home. Now its in the driveway and I indend on pulling the bearings and checking them, repacking them, etc.
Does anyone have a link to doing a bearing R/R including especially the torque specs? I believe I have to pull the bearing buddy to redo the bearings is this correct?
I have all the tools, but no specs on torque, etc on the trailer. I can get part numbers on the bearings themselves. Should I replace all the seals even thought they are new, "just because"? No way am I going back to the "mechanic". Lesson learned. Don't farm out anything that you can reasonably do yourself.

Chris

Re: wheel bearing replacement

Posted: Fri Aug 13, 2010 8:55 am
by Don T
Hello,
In all fairness, those bearing buddies do not like to stay in. Sometimes I have luck and a pair can be reused a few times but I have had them fall out when on the road. The chrome plated bodies do not hold their size and are slippery. I have taken to doing a light knurle so they stay in. We'll see, I just lost one last time out. I'm still running the original drums and have disassembled the bearings for inspection every year since 1995.

Don

Re: wheel bearing replacement

Posted: Fri Aug 13, 2010 10:22 am
by Phil M
Do not replace any seals unless they are leaking. "If it ain't broke, don't fix it." :idea:

Remove the bearing buddies to repack the bearings. I use a large monkey wrench to remove the bearing buddies. I also had to remove the disk brake housing on my 2006 trailer too. One of the disk brake nuts was extremely difficult to remove. There are two nuts for each disk brake. Find a way to support the disk brakes instead of letting them hang, as they are still attached to the metal brake lines. Clean out all the old grease that you can. The torque after wiping off the old grease, and putting on new grease, is 18-20 ft lbs as you rotate the wheel. Wipe off any excess new grease that comes out of the bearing buddies before you put the cap back on. Buy a torque wrench for measuring the tightness of the bearings (about $25 for a cheapo) and for the trailer lug nuts (85-95 fts lbs). Recheck the lug nuts after you use the trailer the first time after repacking. They will normally lose tension.



Phil M :macm:

Re: wheel bearing replacement

Posted: Fri Aug 13, 2010 5:12 pm
by Catigale
You aactually dont have to torque wheel bearings. You tighten the nut until axial play is gone, and just gone....a little bit of slop is actually ok too.

Re: wheel bearing replacement

Posted: Fri Aug 13, 2010 5:30 pm
by Don T
Hello,
I do not recommend running wheel bearings with slop, especially on our trailers. You will have unpredictable roller contact and wear. Zero tolerance is OK but you have to make sure the grease has smooshed out of the bearings by hand turning and rechecking tightness. A small torque of 20 INCH pounds will guarantee bearing contact and wont be excessive when the hub heats up.

Don

Re: wheel bearing replacement

Posted: Fri Aug 13, 2010 5:39 pm
by Craig LaForce
I disagree. The procedure I was taught is to tighten the wheel bearing castle nut reasonably hard, then back it off to the first hole to put the cotter pin in. It is a 2 step procedure.

Re: wheel bearing replacement

Posted: Fri Aug 13, 2010 9:13 pm
by impinnacr
Thanks for all the great suggestions. the great thing about this board is all the experience and info. I'll take it all to heart.
Chris

Re: wheel bearing replacement

Posted: Sat Aug 14, 2010 2:51 am
by Catigale
18-20 ft lbs as you rotate the whee
Thats too tight for a roller bearing.

Re: wheel bearing replacement

Posted: Sat Aug 14, 2010 7:55 am
by Don T
Hello,
Tightening the bearings "hard" is done to force the grease out from between the surfaces while you rotate the wheel, backing out one hole on the nut is not a sufficient "specification" allowing too much variance in the torque. Specifications are derived from the hot running torque (requires defining "hard" :o ).

20 ft lbs is too tight for a grease lubed bearing. Higher torque specs are used with oil lubed rollers such as pinion bearings, although it can be much higher like 90 ft lbs.

Bearings set too loose suffer impact "shock" loading, which will "print" divots in the race, as well as exert uneven loading across the length of the rollers and face of the race.

Re: wheel bearing replacement

Posted: Sat Aug 14, 2010 11:05 am
by Craig LaForce
Well, you kinda have to back it up to the first hole alignment or you won't be putting the cotter pin in.

I always leave wiggle room in my descriptions, but not so much in my bearings.

Re: wheel bearing replacement

Posted: Sat Aug 14, 2010 1:02 pm
by Catigale
Well, you kinda have to back it up the the first hole alignment or you won't be putting the cotter pin in.
:D :D

This thread is too racy for me...a real roller coaster of emotion.