Wheel/Brake/Bearing Question

Bull Rider wrote:
I think you need to pull the wheels off and LOOK and see what's going on with your bearings, and brakes, and the entire wheel assembly.

Bearings, brakes, etc. are just too important to leave to guessing. Plus the other components need to be checked.

X2

A small amount of bearing play is normal and required on a trailers axles. In fact bearing will last longer with a small bit of play. Bearings should never be tight.

This from Dexter on "bearing adjustment and play".

Bearing Adjustment and Hub Replacement
if the hub has been removed or bearing adjustment is required, the following adjustment procedure must be allowed:
1. After placing the hub, bearings, washers, and spindle nut back on the axle spindle in reverse order as detailed in the previous section on hub removal, rotate the hub assembly slowly while tightening the spindle nut to approximately 50 lbs.{t (12" wrench or pliers with full hand force).
2. Then loosen the spindle nut to remove the torque. Do not rotate the hub.
3. Finger tighten the spindle nut until just snug.
4. Back the spindle nut out slightly until the first castellation lines up with the cotter key hole and insert the cotter pin (or locking tang in the case
of E-Z Lube TM).
5. Bend over the cotter pin legs to secure the nut (or locking tang in the case ol E-Z Lube TM).
6. Nut should be free to move with only restraint being the cotter pin (or locking tang).

And proper bearing end play;

Nev-R-Lube Bearing End Play inspection.
The following lists the maximum axial end play for each of the sizes of, Nev-R-Lube bearings and the amount of tilt that can be expected, Since there are a large number of wheel and tire combinations in use on trailers, the tilt is expressed in inches per inch. The movement as measured at the tire tread can be found by the following method:
Example: if the tilt value is shown as .003" per inch and the tire measures 30" in diameter, simply multiply .003' X 30' = .090" which is the total expected movement at the tires' outer diameter.

Bearing size End play resultant tilt value
35 MM .005" axial .003'7 per inch
42 MM .006" axial .005"/ per inch
50 MM .O08" axial .004"/ per inch

the above is a snipped copy and paste from Dexters "hubs/drums and bearing" PDF

I could not disagree more with the above statement about bearings needing to be lose. Lose bearings ride on just a few of the pins instead of evenly dispersing the load to all the surfaces. This causes premature wear on all the surfaces.

If you are at all inclined to believe that bearings should be lose then please do more research.

Obviously Scott is smarter than all the Engineers at Dexter put together!

Well there is a difference between "loose bearings" and bearings that are set to their correct specifications.

However that description posted by Jimlin looks to be about right. The only part I didn't care for was the lack of proper torque specs: "just snug" is hardly an exact measurement. :)

FWIW the procedure to set the preload on the front hub bearings on my Dodge 1-ton are very similar to those posted. The exception being that they specify 18 in.lbs. instead of "just snug". :)

Allworth wrote:
Obviously Scott is smarter than all the Engineers at Dexter put together!

"If" they wrote that (I have the procedure for both dexter and Alko and don't see anything that says bearings should be lose..) then not only am I right but every experienced mechanic, trade school and knowledgeable DIYer is smarter.

Howard, you've got the idea. Even "snug" is not lose ie has play.

I spent my entire career in the bearing business. 40 years; Including teaching proper bearing handling/maintenance. Most bearing failures are the result of poor maintenance that includes overgreasing, improper mounting, and contamination caused by improper installation. Do "not" preload your trailer bearings. Follow the procedure from Dexter as posted above. Preload will cause overheating which leads to premature wear and grease failure which leads to bearing failure. Also, pumping in all that grease just fills the cavity and could blow the seal. That extra grease does nothing but make a mess. If you notice, every instruction tells you to simply pack the bearing well with the proper grade of grease. That's all that is needed to provide thousands of miles of service. The bearing actually purges the excess grease in the first few moments of operation. Boat trailers recommend filling the cavity to help keep water out. When the boat trailer wheels are submersed into the water, the temperature change can pull water into the hub cavity, so the extra grease is there to protect from this water intrusion. Other trailers should never see wheels under water, so all that extra grease is needless. You will never have a bearing problem if the "manufacturers" guidelines are followed. Any other advice can be harmful. I would see this in many maintenance training classes where people would tell me "I've been doing it this way for years (the wrong way)and never had a problem".. It was interesting that those were the customers who spent the most on bearing and machine maintenance. Bottom line - proper amount of grease, new seals, clean hands, clean work area, clean spindle, clean hub, proper running clearance (no preload) = no problems.

People keep saying "preload"... I take that means snugging the bearings so there is no play at all? Meaning they are tight?

Which I don't do... as all my trailer maintenance guides say, tighten the castle nut, but then back it off to fit the cotter pin in it. That allows for just a very small amount of "play" when you test the wheels.

MTPockets1 wrote:
I spent my entire career in the bearing business. 40 years; Including teaching proper bearing handling/maintenance. Most bearing failures are the result of poor maintenance that includes overgreasing, improper mounting, and contamination caused by improper installation. Do "not" preload your trailer bearings. Follow the procedure from Dexter as posted above. Preload will cause overheating which leads to premature wear and grease failure which leads to bearing failure. Also, pumping in all that grease just fills the cavity and could blow the seal. That extra grease does nothing but make a mess. If you notice, every instruction tells you to simply pack the bearing well with the proper grade of grease. That's all that is needed to provide thousands of miles of service. The bearing actually purges the excess grease in the first few moments of operation. Boat trailers recommend filling the cavity to help keep water out. When the boat trailer wheels are submersed into the water, the temperature change can pull water into the hub cavity, so the extra grease is there to protect from this water intrusion. Other trailers should never see wheels under water, so all that extra grease is needless. You will never have a bearing problem if the "manufacturers" guidelines are followed. Any other advice can be harmful. I would see this in many maintenance training classes where people would tell me "I've been doing it this way for years (the wrong way)and never had a problem".. It was interesting that those were the customers who spent the most on bearing and machine maintenance. Bottom line - proper amount of grease, new seals, clean hands, clean work area, clean spindle, clean hub, proper running clearance (no preload) = no problems.

good post

ScottG wrote:

Allworth wrote:
Obviously Scott is smarter than all the Engineers at Dexter put together!

"If" they wrote that (I have the procedure for both dexter and Alko and don't see anything that says bearings should be lose..) then not only am I right but every experienced mechanic, trade school and knowledgeable DIYer is smarter.

Howard, you've got the idea. Even "snug" is not lose ie has play.

Loose is your term.
Dexter nor I nor anyone says they need to be loose and anyone that has any experience of using and replacing wheel bearings on heavy vehicles knows a pre loaded or snug bearing won't last long especially when carrying those heavy loads.

The OP will be wise to follow Dexters recommendations. Every new truck or trailer I put in service I pulled the hubs and check for proper grease and reset the bearings. When your on the road making a living its small things that can make for thousands of miles of event free service.