Moderated Discussion Areas
  ContinuousWave: The Whaler GAM or General Area
  Burnt-up bearings

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Burnt-up bearings
Dauntless17 posted 04-16-2002 01:11 PM ET (US)   Profile for Dauntless17   Send Email to Dauntless17  
I just re-packed one set and replaced the other set of trailer bearings. This is the first time I've done it. Just want to make sure I did it right. How warm/hot should the bearings get when trailering on the highway at 65 mph? I trailered it yesterday and stopped to check them a few times. They were warm enough that I could hold them in my hand for about 5-6 seconds before I had to let go. Is this OK?


JFM posted 04-16-2002 01:27 PM ET (US)     Profile for JFM  Send Email to JFM     
It's OK warren, but you want them to cool down to ambient temperature before you put the trailer in the water. Many use Buddy Bearings for this reason,they fill the bearing with cooler grease and think this helps, but I always wait a while for them to cool dowm on their own. Also, the size of wheel on your trailer can effect the teperature of your bearings, smaller wheels turn higher RPM= more heat.
Regards, Jay
triblet posted 04-16-2002 04:25 PM ET (US)     Profile for triblet  Send Email to triblet     
They should only be warm to the touch, except
maybe on a REALLY hot day (100+). It sounds
like they were hotter than they should be.

How much did you tighten the big nut? Spec is
like 20 INCH-pounds, which is not much.


jimh posted 04-17-2002 12:29 AM ET (US)     Profile for jimh  Send Email to jimh     
If the bearings are running properly, they really don't get very much warmer than the rest of the wheel and tire.

On a hot day, the tires may run a bit warm to the touch, and the wheel and bearing will warm to this same point. If the bearing is noticeably hotter than the wheel, I'd think it is running a little on the hot side.

rsgwynn1 posted 04-17-2002 12:38 AM ET (US)     Profile for rsgwynn1  Send Email to rsgwynn1     
Be sure to check the inside of your wheels to make that the seals aren't blown. You can pack all the grease in the world in there and it'll still run out on the inside (where you can't see it). Buddy Bearings (or a comparable brand like Red Eyes) are a must, especially in salt water.
Dauntless17 posted 04-18-2002 02:11 PM ET (US)     Profile for Dauntless17  Send Email to Dauntless17     
The way I tightened the nut was to crank it way down and then back it off a 1/2 turn several times to seat the bearings.

Then, with the wheel in the air, I spun it while tightening the nut. When the pressure caused the wheel to stop, I backed it off about 1/4 turn and put in the cotter pin. The wheel spun fairly well while suspended after pinning it.


Dr T posted 04-18-2002 03:14 PM ET (US)     Profile for Dr T  Send Email to Dr T     
That is way too tight.

Suggest that you back off and then tighten to finger tight. Then use a wrench to tighten it just enough to slip a cotter pin in. As Chuck points out, 20 in. lbs. is not very much at all.

triblet posted 04-18-2002 04:49 PM ET (US)     Profile for triblet  Send Email to triblet     
Or get a low-range torque wrench. The beam type
are about 20 dollars. Be sure it goes that
low -- most don't. Or, for about $60 (IIRC),
Sears has a low-range click type.

I have one of each. The beam type lives in
the hub replacement kit that travels with me.


Hoss posted 04-18-2002 06:01 PM ET (US)     Profile for Hoss  Send Email to Hoss     
It's always better to be a little too loose than too tight. I go hand tight after seating with a wrench then back off 1/4 turn.
whalerron posted 04-18-2002 10:53 PM ET (US)     Profile for whalerron  Send Email to whalerron     
Hoss is right. Unlike pinion bearings, trailer bearings should never be preloaded. Preloaded wheel bearing will fail much earlier than "loose" bearings. There is a real good technical service bulletin about this on the Timken bearing site
but there site is down right now and I cannot get to it.

Typically, a wheel bearing should be set to have 5 to 10 thousandths endplay. On many trailer spindles, the only adjustment is a bearing nut that has slots cut in it for the cotter key. With these, it always seems that one slot has the wheel too tight and the next slot has it too loose. It should be set to the "looser" position. The Timken bulletin contains some graphs which show why this is true. They also have posted a technical service bulletin which explains why too much grease in a hub is bad for the bearing.

- ron

whalerron posted 04-19-2002 08:37 AM ET (US)     Profile for whalerron  Send Email to whalerron     
Ok, here is the link to the Timken Bearing article regarding wheel bearing preload. Take note that they say if you can get the preload exact, bearing life is extended but if you get it wrong, the bearing will fail prematurely. According to this TSB, the caveat here is that there is no way to accurately measure bearing preload. The gist of the TSB is that, because of this preload measurement issue, wheel bearings should have endplay.

Based on the info in this TSB, I would say that Dauntless has the bearings adjusted too tight.

What is wheel bearing Adjustment? (page 1)

What is wheel bearing adjustment? (page 2)
[url]What is wheel bearing Adjustment? (page 1)[/url]

whalerron posted 04-19-2002 08:38 AM ET (US)     Profile for whalerron  Send Email to whalerron     
What is wheel bearing adjustment? (page 2)
Dauntless17 posted 04-19-2002 05:10 PM ET (US)     Profile for Dauntless17  Send Email to Dauntless17     
I pulled the Bearing Buddies off and checked the nuts. I loosened them to where one cotter pin slot leaves no play in the bearing when I push and pull on the wheel. If I back it off one slot, I can feel slight play in the bearings. Which of the two settings should I use?


Jerry Townsend posted 04-19-2002 06:07 PM ET (US)     Profile for Jerry Townsend  Send Email to Jerry Townsend     
Warren - the correct one is where you have just a slight end-play - because, as the bearing heats up it expands and therefore it will get tighter. If you use the tighter case, the bearing will be far too tight as it expands - which only makes it hotter and hotter.

There are a lot of good words above - but remember that a bearing adjusted too tight is a failed bearing - flat guaranteed. A bearing that you cannot comfortably hold in your hand is too hot - caused by being too tight or not enough grease.

My way - from my master mechanic father - tighten by hand, then LIGHTLY use a wrench until firm contact is felt with the tire/wheel being rotated and then back off the nut to the next cotter-pin notch. Specifications state 10 - 12 in-pounds prior to the 'back off' which is about 1 pound on a 12 inch wrench - not much. --- Jerry/Idaho

whalerron posted 04-20-2002 12:15 AM ET (US)     Profile for whalerron  Send Email to whalerron     

set it to the "loose slot" position. While this doesn't intuitively seem correct, it is the proper setting. You will drastically INCREASE the life of the bearing by setting it slightly loose instead of tight.

Look at the graphs on the Timken Bearing page. This is exactly how they suggest setting those bearings.

- ron

FISHNFF posted 04-20-2002 01:14 AM ET (US)     Profile for FISHNFF  Send Email to FISHNFF     
On a similar note, has anyone used those new bearing and hubs which are bathed in oil, not grease? I know the design has been around, and I see them in use on heavy duty vehicles. I've even read that they increase mileage due to less drag.
Pros and cons?


Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.