Thread: OT - Wheel Bearing Temperature

What is an average or max. temperature for a wheel bearing without going into failure. In my case next week towing a trailer & wanted to check bearing temps. at rest stops with a hand held temp gun. A couple few years back I had a problem, but was lucky I was a couple blocks from returning home when noticed. The hub was so hot it blew the bearing buddy off & knocked the hubcap off too!

If the bearings are greased, adjusted and in good shape, you shouldn't need to worry about temps unless your over loading.

Tom

Bearing temps is not a spec they actually put in any book. It cmes down to a case of, if it is hot enough to peel the paint off the hub, they are either dry or too tight. If it gets hot enough for the hub cap to come off, you probably need to consider axle replacement. The temps generated to cause the hub cap to come out would likely be considerable, and may have caused some of the hardness to come out of the spindles. If you had greased the bearing buddies, and it still got that hot, the bearings must have been too tight, or the trailer overloaded to a great extent. Or a multipurpose grease must have been used, bearing grease with the right properties is just as important as lug nut torque, a moly EP grease with a high temp rating are a good start, but finding the actual grease the trailer or bearing manufacturer called for is even better.

I don't have a specific temp for you, but IMHO...if you can smell them they're too hot and if you can't hold your hand on the hub they are too hot. A infrared temp gun is neat but the nose test and the hand test are adequate in my mind.

Stuart.

Originally Posted by blake in spokane

What is an average or max. temperature for a wheel bearing without going into failure. In my case next week towing a trailer & wanted to check bearing temps. at rest stops with a hand held temp gun. A couple few years back I had a problem, but was lucky I was a couple blocks from returning home when noticed. The hub was so hot it blew the bearing buddy off & knocked the hubcap off too!

Sound like a combination of too much grease and water in the bearing. It got hot enough to boil the water and the steam blew the cap off. The "Bearing Buddy" is no friend of your bearing. It encourages overgreasing, which results in high temps and a big mess.

Originally Posted by tdmidget

Sound like a combination of too much grease and water in the bearing. It got hot enough to boil the water and the steam blew the cap off. The "Bearing Buddy" is no friend of your bearing. It encourages overgreasing, which results in high temps and a big mess.

But it (bearing buddy) DOES keep the water out of the bearings and that was its purpose. For boat trailers that are dunked in the lake several times a summer it served a purpose.

Stuart

My opinion is that if the hub is more than slightly warm to the touch then it's too hot. I'm sure this is grossly over conservative, but if your bearings never get hot, you'll never have a problem, right? Now if you were driving all day with high ambients, at speed, and carrying a high load, and the hubs were equally warm to the touch, I wouldn't be terribly worried. Similarly loaded hubs at different temps are a bad sign, though.

Steve

Ya I mean, stuff here gets too hot to hold onto when it's sitting still in the sun. If it's over 200 deg I'd start getting worried. I've clocked temps on OE serp belt bearings / pullies on cars without an issue at nearly 300 deg F here- but that's in an engine bay.

Originally Posted by atomarc

But it (bearing buddy) DOES keep the water out of the bearings and that was its purpose. For boat trailers that are dunked in the lake several times a summer it served a purpose.

Stuart

But it is a toss up as to which is worse. On the way home from the lake normal bearing temps (160-180) will drive out a lot of water. Too much grease is as bad as too little. Remember that in most cases the trailer wheels sre turning more rpms than the tow vehicle. So , given the severe usage, extraordinary care and frequency of lubrication is in order. Lots more work than a couple of extra shots in the "Bearing Buddy". Bearings are normally filled to 25-30% capacity with grease. The "Bearing Buddy" depends on 100% fill.Wayyyyyyyyyyyy wrong.

i tow a lot of boats here in florida, if you can't hold the hub or bearing cap its to hot (a guess 140 deg F max), i have seen brakes drag and set wheels on fire too. Beware of these oil filled bearing hubs on the market, one leak and in less then a mile the oil is gone and the bearing race is blue. grease is king

The rule of thumb I use is one hub a lot hotter (say, 30 degrees) than the other (or others). This takes into account whether there are brakes or not.

bearing grease is rated normally 200 to 300 degrees F
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in general if outside of bearing housing is over 200F you got a problem.
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try
McMaster-Carr
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temperature indicating stickers we use on industrial equipment. we used non reversible type. basically they record highest temperature and you need a new sticker if you want to test measure again.
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by the time you stop and get out to measure the bearing is already cooling off. you want highest temperature bearing got to while you were running it.

I regularly tow my 10,000 lb capacity trailer with a load varying from 6,000 lbs to 8,000 lbs. It never gets more than a few degrees over ambient temperature on a trip of 100 - 200 miles.

I agree with weirsdale george. ---Trevor