how hot is too hot?

[beardrum]

Hi Everybody,

Long story short, I pulled the hubs on my 2014 16' Scamp, and repacked the wheel bearings and adjusted the brakes. I just took it for a test drive down the freeway a couple exits and back (maybe 10 miles), and when I got home I found one hub (driver's side) is considerably warmer than the other - not hot, but definitely warmer than the other one, which was pretty much air temperature.

So the question is, is that temperature differential enough of a concern to pull the hub again and re-do the packing on that side?

Thanks for any advice.

Chuck

[John in Michigan]

A couple of things:

1. The retaining nut holding the hub on the axle should be tightened snug (with no wobble when you wiggle the wheel), then loosened 1/4 turn.

2. Temperatures under 200 degrees F are OK. Use a temperature gun to check temperature at the outer hub and also the brake drum if you are trying to track down the heat source.

3. On multiple occasions I've had problems indicated by large temperature differences (e.g., 30 degrees F or more). In each case the source of the problem was a brake. In one case, the brake magnet clip had broken, so the opposite brake was getting hot doing all of the work! In all other cases, just needed to adjust brake tightness on one side.

[John in Michigan]

Also, recently after replacing the bearings and seals, I noted that one side was significantly warmer. Using the temperature gun, I determined that the difference was only about 25 degrees F. Both sides in were 110 to 140 degrees F. But I also noticed that the e-brakes were noisy and jerky when stopping. I disassembled to warmer side hub and inspected the brake. Everything was OK. Reassembled. Still a temperature difference. I reduced the braking power current and the "problem" went away.

[CharlesinGA]

Originally Posted by John in Michigan

A couple of things:

1. The retaining nut holding the hub on the axle should be tightened snug (with no wobble when you wiggle the wheel), then loosened 1/4 turn.

A quarter turn is way too much...............

Thread on the spindle/nut is 1"-14 so each quarter turn is give or take, 0.018" (eighteen thousandths) and Timken recommends on everything from Semi trailers down to small trailers like this, 0.005" end play max. Even one flat could be too much (assuming the installer found zero end play by repeatedly tightening and loosening (gently) feeling for the sweet spot that is zero end play).

I changed my spindle nuts to the newest Dexter nuts which have 12 slots rather than 6, allowing for a finer adjustment.

Charles

[redbarron55]

All of the above, but repacked bearings will run warmer than before until the excess grease has worked it's way out of the bearings.
Also brake issues will warm them up too.
I like to coast to a stop (more or less) at a rest area along a trip and then feel the hubs.
The sunny side will be warmer as well.
You should get in the habit of touching the hubs at almost every stop and get the "feeling" of normal heat.

[FlyGuy]

The side that's exposed to sun will always be somewhat hotter than the other side.

[thrifty bill]

Get data not guesses. You can get an infrared thermometer at Harbor Freight or wherever for around $30. Well worth it.

[bigangelman]

How tight did tighten it? I'd back it off 1/4 turn and try it again.

[woodchipper]

We routinely check ours at gas/rest stops with a laser thermometer. Ours consistently runs between 100-120 depending on the ambient temp. Both sides are usually within a 5 degrees of each other.

[Marty Smiltneek]

Wheel bearings are almost universally over packed with grease. You need enough grease to coat the surfaces byt not so much grease tht the grease is pumping in a circle! Pumping causes heat.

[Lynn Eberhardt]

The warmer side could be the result of the brakes being a little "over adjusted." Don't worry about a slight difference if you can still hold your hand on the hub.

[gordon2]

Originally Posted by redbarron55

All of the above, but repacked bearings will run warmer than before until the excess grease has worked it's way out of the bearings....

IMHO I agree that it is normal, or at least common and not a concern, to see one or both bearings running a little warm for a few miles after a repack. I don't worry about it unless its too hot for me to keep my hand on the hub.

[Civilguy]

Timken says 1/4 turn and they also say 0.005". But, they also say more than just those two things.

Personally, I'd consult their website to see what-all they have to say.

https://www.timken.com/resources/man...18a-laminated/