Check your hub temps!

[motocamper]

I always check my hub temps with an IR gun at each fuel stop. On our first trip with the new Momentum I noticed that the middle hub on the right side was running 40 to 50 deg hotter (180-190) than the others. I called Dexter to ask about normal operating temps. BTW, they said the grease in the hubs was good up to 300 deg. Dexter said this was in the normal range for the load, but I still didn't like having such an outlier on just the one hub. I pulled the tire and bearing to inspect. It was full of grease, but the bearing preload seemed too tight. I backed the nut off 1 notch on the clip. This put just a tiny bit play in the hub. The temp now is right in line with the others.

[Cate&Rob]

motocamper Good Advice!
The small amount of play when the hub is cold is required so that when all components come up to operating temperature and each one expands a little . . . bearing preload does not become too tight.

Rob

[kevinpo]

motocamper
On a big Momentum that would've caused you problems down the road (literally ) Good catch!

Happy Momentuming,
Kevin

[Country Campers]

"Momentuming"?
Brian

[TucsonJim]

Great catch, and very informative post.

[Country Campers]

Is the "normal" operating temp that you see in the 140-150 range? Roughly how many miles between checking?
Just looking for info for comparison.
Thanks
Brian

[Guest]

This is a great catch but when you get home, recheck the pre-load. This is done cold by rotating the hub/wheel and torqueing the hub nut to the specifications in your manual (typically 50 ft-lbs) then without rotating the tire, back off the nut and re-tighten finger tight.

http://www.dexterpartsonline.com/fil...e%20Manual.pdf

[Buckskin]

I also use an infrared gun to check temps of hubs and brake drums when we stop for fuel. On a hot day with bright sunlight the side facing Sun runs a little hotter. Did notice one brake drum was running a little hotter and I had brakes adjusted a little tighter than others and backed off adjustment. To me an infrared temp gun is a great tool to detect problems before they become major ones.

[motocamper]

Just to update this. My hub temps have dropped slightly since new. I attribute this to break in and coincidently slightly more play in the bearings. I have 3k on the rig now. Hub temps this weekend were all in the 120 F range with ambient temps of 90 to 95F, axle weight of nearly 16k spread over 3 axles.

[Ronster]

Something I experienced with hot hubs was caused by poor brake adjustment. As we were traveling down the highway, I felt something binding up with the trailer wheels, and my friend following behind me (fortunately a certified RV repair technician) could actually smell the hot brakes. When we stopped, sure enough the wheels (hubs) were hot, some hotter than others. Several days after we arrived at our next campsite (after it quit raining long enough), we checked the brake adjustment and found they were pretty far out of whack. The ones that were the most out of adjustment were the ones that were hotter when we stopped to check that day on the highway. We adjusted the brakes - by turning the adjustment star wheel until the brakes dragged then backing them off a couple of clicks - and everything worked perfectly next time I hit the highway. My friend of course understands the details behind electric brakes more than I do, but it seems that when the brakes get out of adjustment and you adjust your brake controller a little higher to compensate, the electromagnets work overtime. If you experience hot hubs, it could be a more serious problem than what I experienced, but checking the brake adjustment first, which is a simple process, may solve your problem before considering a more complex diagnosis.

[Country Campers]

Thanks for the great input. Makes perfect sense.
By the way welcome to the forum, glad to have you here.

Brian

[Cate&Rob]

As we were traveling down the highway, I felt something binding up with the trailer wheels, and my friend following behind me (fortunately a certified RV repair technician) could actually smell the hot brakes.

While it is possible that the auto-adjusters on your trailer brakes have over tightened the brakes, if your trailer brakes are applied when your truck brakes are not (travelling down the highway) there is likely something wrong with the wiring that energizes the electric trailer brakes, or quite possibly the break-away brake apply pin has been pulled.

Rob

[Guest]

I've heard of these auto adjusters becoming too tight which is odd. Years ago most everything had auto adjusting drum brakes and they worked well...for drum brakes. Makes me rethink moving to this type of brake when mine need replacement.

It would make sense if all coaches came with disc brakes these days where the additional cost when new should not be a significant factor. Or at lease offer this as an option.

[Ronster]

Thanks for the welcome Country Campers. And thank you Cate&Rob for the good advice - I failed to mention that after the brakes were adjusted properly, everything worked perfectly, and I was able to back off the brake controller down to where it was.

BTW, as a newbie to the forum, I could not figure out how to add the attachment to my posts, where it includes "vitals" such as tow vehicle, trailer, etc. If someone can link me to that discussion, I would be most appreciative.

Ron

[Ronster]

Also failed to mention, and just realized, that the dealer had fixed a brake problem on one hub and apparently adjusted it to specs but did not adjust the other brakes to match. That one hub was much cooler to the touch than the others. Sitting through last winter's wet weather in Texas may have played a part as well. I just hope all this helps someone else sometime, I know I've learned something from the experience.

Ron

[Canyonlight]

[QUOTE=Ronster;n4756

BTW, as a newbie to the forum, I could not figure out how to add the attachment to my posts, where it includes "vitals" such as tow vehicle, trailer, etc. If someone can link me to that discussion, I would be most appreciative.

Ron[/QUOTE]

Ron - check this thread out......I think this is what you are looking for: https://gdrvowners.com/forum/main-fo...to-add-or-edit

Dan

[Ronster]

Dan, you're a saint - thank you!