Wheel Bearings Showing Heat?

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firehoser75

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Mar 6, 2011
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I have a one year old trailer. I just took apart 2 hubs (same side of trailer) and found that the inner bearings on both axles (same side of trailer) have grease "cooked on" to inside where they run against the spindle. Using solvent and a small brush, I could not remove all of the cooked on grease. Otherwise, the bearings look good. There is a very slight discolouration (cooked on grease) on the spindle. There was lots of grease in the bearings and hub, the trailer only has 6000 miles on it and is just over 1 year old now. I was doing the bearing prior to the next trip.
The brakes show no signs of any heat damage. During my first year using the trailer, I have weighed 3 times, never being overloaded. What could have caused this and do I have to replace the bearings and races?
Thanks for your knowledge, this is my first trailer.
Tom
 
Assuming you LOOKED at all bearings?
If other bearings (other side) OK, then replace bearings on effected side (keeping old bearings for "bearing man" to examine). I mean a mechanic who replaces bearings regularly.

This will give you peace of mind, and allow you to gain knowledge of bearing wear.

As to WHY one side "May" be getting all the weight.....? Someone else may have an answer. Anything is possible with regard to Axle assembly on these trailers....., wrong bearing kits, misalignment, I just do not know.
Situation requires watching.... buy a "Inferred temperature monitor" to keep EYE on hubs as you travel.

Hope someone else will add additional insight. 
 
I got one of those infrared temp guns at Harbor Freight (about $25) and it has helped me understand what is happeneing in the hubs much better.  Whenever I stop I check them and watch how much they differ. If one of the wheels is 50 degrees higher than the others, I can expect there is a problem developing there and deal with it beofre it causes a failure.  I also switched grease and am using "green grease" which has a much higher temp rating.  I assume that would help in your situation if you are using a lower rated grease.  Their advertisements claim it lasts up to eight times as long as standard wheel bearing grease.  Not sure how they figrue that but it has helped me.  It is synthetic.
 
It sounds like they may have adjusted the bearings a little too tight. A tight bearing will create heat. If it is too tight it will destroy the bearing. I would replace the affected bearings and make sure they are adjusted properly buy a qualified mechanic. I would also use a good synthetic wheel bearing grease.
 
I would replace the bearings.  They are cheap compared to a bearing failure on the road in the middle of no where.  Also be sure to replace the bearing races.
 
It's also possible the "cooked on grease" just had the carrier liquid separate out and make it stiff. If the bearings are packed with grease and there's no metal discoloration (turning blue), I'd clean it all out good, grease correctly, and reassemble with new seals.
 
I also have an infrared laser gun that I check temps with occasionally to make sure all the hubs are about the same temp.  I also take readings on the tires.  If there is a tread separation or the tire is a little low, it'll help me realize there is a problem.  I was able to find a tire with a tread separation when I noted about a 40 degree increase in one tire.  A few days before that, I lost a tire that I didn't catch in time.  I guess the poor mans method works part of the time!!!
 
Having retired after 38 yrs as a millwright in a pulp and paper mill I have changed and inspected 100rds of bearings.Number 1 reason for bearing failure is improper installation, that being cocked or over tightened. To tight causes friction whitch causes heat.Number 2 reason wrong grease I have to agree with previous post about getting a heat gun and keep check on temps that can find a number of problems.We always get the?  How hot is to hot, that depends a lot of things but has long as all are about the same should be ok but 160?-180? is starting to show problems.Happy camping
 
How do you feel about miles on the bearings.  Some recommend repacking every year.  But is that necessary if the milage is low?
 
i have a sled trailer that has bearing buddy caps on the hubs
  you pump the hub full of grease and as time goes by the cap retracts back in to show that the grease is getting used up. all you do is put on the grease gun and  pump the hub full of grease again and the cap comes back out  i dont know if this product is available for tt or not. anyone know for sure?
 
muskoka guy said:
i have a sled trailer that has bearing buddy caps on the hubs
  you pump the hub full of grease and as time goes by the cap retracts back in to show that the grease is getting used up. all you do is put on the grease gun and  pump the hub full of grease again and the cap comes back out  i dont know if this product is available for tt or not. anyone know for sure?
Click to expand...
Yep......have them on every trailer I own and in 45 years of pulling trailers I have never had a bearing failure (knock on wood). I also have been using a synthetic wheel bearing grease since it has become available. The bearing buddies are now coming on many of the new TTs from the manufacture as standard equipment.
 
Carrolla & MissAnne said:
Having retired after 38 yrs as a millwright in a pulp and paper mill I have changed and inspected 100rds of bearings.Number 1 reason for bearing failure is improper installation, that being cocked or over tightened. To tight causes friction whitch causes heat.Number 2 reason wrong grease I have to agree with previous post about getting a heat gun and keep check on temps that can find a number of problems.
Click to expand...

As an ex-auto mechanic who still does alot of auto work on the side, I have to agree.  Except I separate the failure reasons into 4 categories:
1)  Improper installation (not properly seated onto spindle or into bearing race, or wrong bearing) 
2)  Improper maintenance (contamination)
3)  Improper bearing pre-load (adjustment)
4)  Improper lubrication (wrong grease)

Slight discoloration is not abnormal.  It should be very minimal though.  It sounds like you are OK.  But, look very close at the bearing races for evidence of brinelling.  You would not really see this on the bearing cone itself.  You have to inspect the race.  Any evidence at all, replace the bearing and the race as a matched set per wheel.  Brinelling would be evidence of improper bearing pre-load.  With only 6K miles, I wouldn't think contamination/maintenance would be the problem.  The lubrication issue might be.  Only because the factory builds units with minimum dollars needed to build, versus maximum dollars in profit in mind.  And it's possible that bearing seals allowed contamination (dirt).  If this is all new to you, have it done by a qualified tech. 

If I were you, and I had doubts about the "cooked grease" and discoloration, I would replace the bearings and races in matched sets.  Along with new seals.  If under some kind of warranty, take advantage of it.

Once done, follow the maintenance schedule for proper wheel bearing service.  You will be restarting with a clean slate and peace of mind.  And someone else to blame a problem on, other than yourself.



 
Thanks everyone for the responses. I find it very helpful. Mark, I really appreciate your detailed advice as I am a newby to trailering and this is the first time I have done wheel bearings. I have contacted Lippert regarding warranty, and they are looking at some photos I took and considering it. "Technically" the one year part of the warranty ran out in May 2012. I finished my last trip (snowbirder) in April and the trailer has been parked with the weight taken off the wheels since. I was trying to prepare for the next snowbird trip when I discovered the situation.
I understand that the races should be pressed in at a shop rather than just "hammered" in by a novice. Therefore, it would be less expensive and troublesome to just replace the entire assembly than to have a mechanic take apart, replace, and repack the bearings. Around here the labour rate is about $100 per hour. I'll see what Lippert has to say and go from there.
Thanks,
Tom
 
Lowell said:
How do you feel about miles on the bearings.  Some recommend repacking every year.  But is that necessary if the milage is low?
Click to expand...
Some would say it's not necessary, and ever year I tell myself the same thing. But when April comes around I all ways repack.
 
Is it "necessary"?  Probably not but it is a good idea since the effort is so small compared to the penalty if you break down.  If you learn how to do it yourself, it costs very little and the one time I had one blow up in the middle of a trip, I learned how inconvenient it is to get them fixed on the road.  I'm a believer.
 
I've replaced my own races and bearings and it is not too difficult once you get the hang of it.  If you do the races best advice I can give is to save an old race or two and cut a radial slit in it with about a 1/8 inch kerf and use it as a race driver.  The kerf makes it easy to remove. You can tell by the way it sounds when you hit it when its fully driven in place.

If you can see or catch any imperfections in the race with your fingernail, its time to replace.
 
Sounds to me that who ever initially installed the wheels did not correctly tighten the bearing nuts. I'd clean them out, liberally apply new grease and put it all back together. If you don't know how to correctly tighten wheel bearing nuts, look for some one to explain the procedure to you. It's a learned skill.  Getting one of the IR thermometers at Harbor Freight is good advice. Use it to check your hub temperature whenever you stop. If things stabilize, consider yourself lucky and have a beer.
 
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