Spindle, Hub and Wheel Temperature

[JD Eben]

Need a little help from tech experts.

Just had a new Dexter torsion axle with electric brakes put on my 1984 Scamp 13. It was the first thing I had done after buying it. Installed by local trailer pros. New packed bearings and all.

On my first trip out I was checking things over after a 300 mile trip and noticed the spindle and hub/wheel rim were very hot. No smoke or anything just the hot side of very warm. Brakes worked great the whole trip.

So, my question is, is this normal? Should I expect this type of heat, or what should I be looking for in terms of spindle/hub temperature. Any guidance is most appreciated since I need to make the return trip in a week.

P.s still have the 13 rims with 4-on-4 on the trailer.


Sent from my iPhone using Fiberglass RV

[gordon2]

In the last 5-10 minutes before you checked the temp, how much braking did you do? Was there a lot of stop-n-go traffic on hills, or was it pretty much no braking until you stopped and checked? (or somewhere in between).

Also, where was the heat concentrated? On the spindle / bearings or further out on the drum. Was there much difference in the temp between the bearings / spindle and the drum toward it's outside?

Was it too hot to hold you hand or fingers on?

I think this additional info will help the pros reply to your inquiry.

[Donna D.]

Hot asphalt? One wheel hotter than the other and the hot one was in the sun? Sounds crazy, but it's possible.


And, it's possible the castle nut is too tight....

[JD Eben]

I'll try to address several question posted.

I was not in a particularly brake intensive environment, mostly highway but some moderate braking as we approached our destination. The heat was similar from side to side, but as I recall the drive side could have been slightly hotter (?). The heat was most intense on the spindle behind the easy-lube cap and was noticeable, but less, on the rim. I never actually checked the hub but since the rim attaches directly to it, i took the rim temperature as a indication of the hub temp.

Saw a FAQ sheet on the Dexter site that said the hubs are designed for "extreme" temperature resulting from brake use. If I were to grab the spindle firmly with a bare hand, I would need to let go after 4-5 seconds due to the heat. Is this extreme? What should be expected?

I will be calling the mfr soon after the Holiday, but thought I'd check here in the mean time. I already put 300 miles on it, if something were dreadfully wrong I would have thought it would have happened by now.


Sent from my iPhone using Fiberglass RV

[Donna D.]

I have an EZ Lube on my Scamp. The spindle never gets so hot I can't keep my hand on it for however long I choose.

[Jack L]

I would call the axle installer. This does not sound like a Dexter issue. It sounds like an installer issue. You may need an adjustment on the axle nut.

[gordon2]

I do understand that that bearings can run hot when newly installed, but if it were after the break-in period (about 200 miles) than what you describe does sound to me like its too hot. It is a good idea to recheck the bearing adjustment and brake adjustment after about 200 miles so that is my suggestion.

Except for hard braking, I could always keep my skin on the hub, drum and bearing cap as long as I wished. In fact normally they do not feel much over the air temp.

[Paul O.]

The brakes may have been adjusted with slightly more drag than necessary, but that should not be a problem. As Donna noted, the hub (bearings) should be warm after some driving, but never too hot to touch. The drum may actually feel hot after using the brakes. You can stick your fingers through the holes in the wheel to touch the O.D. of the drum.

[JD Eben]

Based on this feedback, I'd say the bearings nut is too tight. I'm out of state on a trip with the camper at the moment and will be looking for some service help before I head home.

Thanks for your help.


Sent from my iPhone using Fiberglass RV

[Paul O.]

If you lift the wheel off the ground, you should be able to feel a minute amount of play in the bearings by pulling on the wheel side to side. When they put the hubs together they reduce the play to zero and then back off to the next notch in the bearing nut, i.e. about one sixth of a turn and then insert the cotter pin.

[JD Eben]

Great tip, thanks! I was planning on jacking up the wheels today to check freedom of rotation. I will also feel for a slight bearing play.

I'm wondering if this is an adjustment a could make myself. Seems like it if I could get a wrench large enough for the bearing nut.


Sent from my iPhone using Fiberglass RV

[mary and bob]

Originally Posted by Paul O.

If you lift the wheel off the ground, you should be able to feel a minute amount of play in the bearings by pulling on the wheel side to side. When they put the hubs together they reduce the play to zero and then back off to the next notch in the bearing nut, i.e. about one sixth of a turn and then insert the cotter pin.

The EZ Lube axle on our Casita does not have the "notched" nut and cotter pin. It has a tab that has to be bent over to lock the nut. Don't know what OP may have.

[JD Eben]

Well, that was easy. The castle nuts were not overly tight, actually they were just snug, almost a strong hand tight fit. This resulted in no play at all. It seems like they were never backed off a sixth of a rotation. I can now fell and ever so slight play in the bearing when rocking the wheel from side to side. Imagine once on the road they got warm and expanded and this made them run hot. I'll be doing a quick road test to see how it's working later today.

My only question now is whether the bearings have been damaged due to running them hot for a few hundred miles.

Any thoughts on how I can tell the condition of the bearings? I spun the wheel and listened for something. There was some sound but not sure what to look for.


Sent from my iPhone using Fiberglass RV

[Darral T.]

If the wheel is/was smooth (not notchy), the bearings are fine.

Here's something I do when I'm checking my hub temps and I do every year. I turn my Prodigy brake controller to ZERO (0) so that no brakes on the trailer is applied during the test. Of course, do NOT do this in very hilly or mountainous areas but I always do it on flat ground. THEN I do a check on my hub temps...otherwise, the brakes can REALLY REALLY mess with your mind. It did me last year and once the hubs get hot from the brakes, it takes a while for them to cool back down.

Just be careful if you dont use the trailer brakes and stay off of hills and away from traffic. I'm not encouraging this; it's just the way I do it. Again, the brakes can/will heat up the hubs and it can make you think the bearings are really getting hot.

Now, if the hubs get too hot to touch WITH NO brakes, then I would look at the bearings/grease. But it sounds like you may have already caught the bearings being a bit tight. That's what concerns me letting "shops" do my bearings EVERY year regardless of the miles. Aint gonna happen with me!

[JD Eben]

More great advice. Just finished a road test with trailer breaking and yes, still feeling hot, both sides. Also, the brakes started to feel "grabby" nearing the end of my 10 mile test. I'll try another test later without engaging trailer brakes.

I partly can't imagine bearings not generating some heat. The idea that after miles on the road the spindle with be at air temperature is not what I'd expect, but very good to know.




Sent from my iPhone using Fiberglass RV

[mary and bob]

sounds more like a brake issue to me. do an adjustment, see what happens

[honda03842]

Too tight and too loose are both bad. We've too loose and it results in strange wear patterns. From what I've heard I'd bet on the brakes.

This is redundant to past posts but we have pressure and temperature sensors on our trailer tires. Watching The read out gives a good picture of what's happening in each wheel.

[Victor Benz]

All I can say, is that on my recent trip with a dual-axle Fiber Stream, I checked all four hubs at 100km (60 miles) out and three were cold, and one was slightly warm. At the next check 200 km (125 miles) later, the three were still cold, and the one was somewhat warmer, but I still could keep my hand on it for as long as I wanted. 50km (30 miles) later, the wheel bearing had completely failed on the warm one, and the hub was riding on the spindle. Only the castle nut was keeping the wheel from coming off.


All bearings had been re-packed three years ago, and I always check hub temperatures by hand whenever I fill up. This was the first time any hub felt warm. I had made a mental note to service the bearings when I returned home. Never made it.


Vic

[Darwin Maring]

Have the same scensors on the camper and truck as the Honda post above. For me, the cost is worth the removing of the worry. The receiver will give a warning if the pleasure or temp moves a certain percentage.

[Ian G.]

One thing to check is the new axle comes with the brakes configured to be mounted in a trailing axle position, the Scamp 13 is probably a leading axle design. If the shop did not swap the brakes side to side then the brakes will not work properly and may be sticking partially applied causing the excess heat.