Hubs 101: Only the front hubs are warm?

[MachSchnell]

I picked up my new (used) baby from Lake George NY last Monday. Below is a photo of the rig with the matching trailer from Performance Custom Trailers. On the way home (325miles) I noticed that only the front hubs would get warm. All the bearings were freshly packed and a complete new brakes system was installed. It has four brand new tires all at at proper full inflation. The work was competed one week prior to my going up to get it.

Can anyone suggest why only the front hubs would get warm? They were not excessively hot. I could hold my hand on them as long as I'd like. It was in the 40 degree range for the entire trip, and half of the trip was at night. I didn't notice any dragging or braking issues other than an initial concern when I first picked it up. There was a significant vibration in the rig that improved after about 20 miles and was gone after an hour. A friend suggested that some air in the lines needed to work itself out. The rear hubs remained cool at the ambient temperature. The trailer had not been dunked since the work was completed.

Below is a photo. I have a 0" rise ball and I'm not sure if I'm really level on the trailer. It is parked uphill in the photo. You can see the new brake cylinder/tongue on the trailer.

Thank you in advance for your expertise and help!

 

[109jb]

Re: Hubs 101: Only the front hubs are warm?

Does it have brakes on both axles or only one? If only one axle has brakes is it the front? Aslo, is it a leaf spring trailer with equalizers or torsion spring trailer. If torsion spring, or leaf without equalizers it is possible that the front axle is carrying more load.

 

[Bondo]

Re: Hubs 101: Only the front hubs are warm?

Can anyone suggest why only the front hubs would get warm? They were not excessively hot. I could hold my hand on them as long as I'd like.
There was a significant vibration in the rig that improved after about 20 miles and was gone after an hour.

Ayuh,...
You don't have a Problem, it's just that it's running slightly Nose down, putting slightly more weight on the leading axle...

The Viberation you felt was the Tires,...
They tend to take a Set, when sitting...
After you ran 'em for the hour, they'd warmed up,+ lost the out of roundness...

 

[TilliamWe]

Re: Hubs 101: Only the front hubs are warm?

Yep, I'm with Bond-o, the trailer is too low in the front, causing the forward axle to bear more weight. He's right about the tires too.

Also, if there are only brakes on the front axle, it would naturally run hotter too.

 

[109jb]

Re: Hubs 101: Only the front hubs are warm?

Yep, I'm with Bond-o, the trailer is too low in the front, causing the forward axle to bear more weight. He's right about the tires too.

Also, if there are only brakes on the front axle, it would naturally run hotter too.

It won't be bearing more weight if it is a leaf spring setup with equalizers.

 

[Bondo]

Re: Hubs 101: Only the front hubs are warm?

It won't be bearing more weight if it is a leaf spring setup with equalizers.

Ayuh,... That's not quite entirely True....
But,..
I ain't gonna argue the point...

 

[Knightgang]

Re: Hubs 101: Only the front hubs are warm?

Ayuh,...
You don't have a Problem, it's just that it's running slightly Nose down, putting slightly more weight on the leading axle...

The Viberation you felt was the Tires,...
They tend to take a Set, when sitting...
After you ran 'em for the hour, they'd warmed up,+ lost the out of roundness...

I agree with Bond-o. Nose down puts a little more weight on the leading axle. While a spring axle setup will transfer weight umong both axles, it is not a 50/50 weight split, therefore the leading axle in your setup will still bear more weight, thus the slightly more heat. Not to worry. I would get a hitch with some rise to tryt o level out the trailer...

Vibration, agree, tires out of round from sitting... Warm up, round out, vibration goes away...

 

[109jb]

Re: Hubs 101: Only the front hubs are warm?

Ayuh,... That's not quite entirely True....
But,..
I ain't gonna argue the point...

OK. You are technically correct, but my point is that if it has leaf springs with equalizers he is going to have to be farther from level than the picture shows to be able to "feel" a difference in the heat from the hubs.

 

[Knightgang]

Re: Hubs 101: Only the front hubs are warm?

I disagree. At an ambient temp of around 40*, the hubs will be kept cool anyway, barring a serious problem with the hubs. The OP said they were warm, but not very much at all. Normal service temp or even below I would imagine...

 

[109jb]

Re: Hubs 101: Only the front hubs are warm?

The OP said front hubs were warm, and rear hubs were cool at ambient. He did not say there wasn't much difference between front and rear. He said front were warm but he could hold his hand as long as he liked and rear were still ambient. That description doesn't say to me that there wasn't much difference in temperature. Could be as much as 60 degrees if the rear were 40 and front were 100. I'm not saying there is a problem at all. Just that if equalizers are present there is another explanation for the difference in temperature. Like my original post said, maybe brakes are on front or non-equalized suspension.

 

[jeeperman]

Re: Hubs 101: Only the front hubs are warm?

or the front hub castle nut is one notch tighter than the castle nut on the rear hubs.

 

[MachSchnell]

Re: Hubs 101: Only the front hubs are warm?

Wow, these are great replies to my original topic.

Here's what I found by actually looking at what I've got: :redface:
Front axle has the brakes.
Rear axle has none.
Tires out of round makes sense on the vibration effect.
Leaf springs but I have to look for some form of equalizing setup. Not yet sure.
I think the front is riding too low.

Should I go to a 3/4" rise or higher hitch?

 

[Bondo]

Re: Hubs 101: Only the front hubs are warm?

Should I go to a 3/4" rise or higher hitch?

Ayuh,.. You need to measure the Trailer Frame, front(near the hitch),+ At the Backend of it,...
Then buy the riser that gets it Closest to Level...

Could be as much as 60 degrees if the rear were 40 and front were 100. I'm not saying there is a problem at all. Just that if equalizers are present there is another explanation for the difference in temperature.

Dude,... 100? is getting quite Uncomfortable....
Equalizers do NOT totally balance an Unbalanced load...
Technically, Nor Practically....

 

[MachSchnell]

Re: Hubs 101: Only the front hubs are warm?

Ayuh,.. You need to measure the Trailer Frame, front(near the hitch),+ At the Backend of it,...
Then buy the riser that gets it Closest to Level...



Dude,... 100? is getting quite Uncomfortable....
Equalizers do NOT totally balance an Unbalanced load...
Technically, Nor Practically....

Thanks, Bond-o. This is making good sense to me.

By the way, I have a friend who is a thoroughly experienced mechanical engineer. He said that in any mechanical situation if you can hold your hand on the item in question for more than 10 seconds that the item is 150 degrees Fahrenheit or less. We're all subjective on assessing heat, but engineers hold that general relationship to be true.

My estimation is that the front hubs were running about 110 while the rears remained at air temp (45 degrees.) Now that I'm aware that the fronts have the brakes, I'm not as concerned about the warmth. I'm going to attend to the tongue height issue now.

 

[Knightgang]

Re: Hubs 101: Only the front hubs are warm?

Thanks, Bond-o. This is making good sense to me.

By the way, I have a friend who is a thoroughly experienced mechanical engineer. He said that in any mechanical situation if you can hold your hand on the item in question for more than 10 seconds that the item is 150 degrees Fahrenheit or less. We're all subjective on assessing heat, but engineers hold that general relationship to be true.

My estimation is that the front hubs were running about 110 while the rears remained at air temp (45 degrees.) Now that I'm aware that the fronts have the brakes, I'm not as concerned about the warmth. I'm going to attend to the tongue height issue now.

Remember that your body temp is 98.6*. Therefore, when feelign heat in metal, it is common for any metal that is cooler than your body temp will feel cold tot he touch, especially in cold weather. I would assume that your rear hubs wee probably running more around about 80*. If there were turning, they were creating some heat. The difference is not really enough to be concerned about...

I still recommend that you get a drawbar with rise, maybe one that is adjustable so that you can adjust to the load and/or different trailers... Also, the brakes on the front axle will make them run a bit warmer from the friction. No worries though...

 

[Knightgang]

Re: Hubs 101: Only the front hubs are warm?

BTW, when looking at your springs, there should be a pivot arm on a mount between the front and rear springs. The rear of the front springs and the front of the rear springs will attach it this pivot arm. This is what helps transfer the weight between the axles...

 

[109jb]

Re: Hubs 101: Only the front hubs are warm?

BTW, when looking at your springs, there should be a pivot arm on a mount between the front and rear springs. The rear of the front springs and the front of the rear springs will attach it this pivot arm. This is what helps transfer the weight between the axles...

Yeah. That''s the equalizer bar that I've been talking about the whole time. You guys didn't think I was talking about load equalizers like go at the hitch did you.

Knowing what the OP has said now, I say the temp difference is related to brakes being on the front axle. As I said before, the trailer angle would have to be more severe than the picture shows for it to be unequal load between front and back, especially if it has equalizers, which I will guess it does. The equalizer will even out the load between front and rear, although not perfectly 50/50, but close enough that it isn't what is causing the OP's uneven bearing temps. Most tandem axle leaf spring trailers have equalizers, but I have seen a few over the years that don't. Mostly homemade trailers though.

 

[109jb]

Re: Hubs 101: Only the front hubs are warm?

By the way. The attached picture shows a red arrow pointing to the suspension equalizer.

 

[Knightgang]

Re: Hubs 101: Only the front hubs are warm?

No, did not think you were refering to an equalizer hitch setup, but was just explaining to the OP what to look for in his spring to see if he had that seup...

Great information in here...

 

[NYBo]

Re: Hubs 101: Only the front hubs are warm?

Here's what I found by actually looking at what I've got: :redface:
Front axle has the brakes.
Rear axle has none.

There's your answer.