Hubs and Wheel Bearings Keep Working Loose Causing Play in the Wheels

Question:

I have a 20foot two 7,000 Lb Axle car hauler trailer, 12x2inch electric brakes, 8 lugs, bearings timken 25580 and 14125A, all bearings, races, brake assemblys, are new, I had drums overheating, replacing the bearings and races and turning the drums stopped the overheating problem so I was not sure if the drums were out of round or the bearings were causing the problem because I replaced them together. The hubs do not get hot and are fine, I thought everything was good to go until I took my first eight hundred mile trip with a load and after went to adjust the brakes and noticed my end play was not .0007 any more, I adjusted all bearings correctly and drove around town empty about 100 miles before the trip and checked the end play before leaving and it was good, after the 800 mile trip loaded my end play on one wheel was about sixty thousands and the other three were about thirty thousands, the castle nut could be turned two notches to take up the slop and the other three could be turned one notch. I contacted timken and they said the tolerance between the bearing 25580 and the spindle can be between two and seven thousands, that seemed like a lot to me but my spindle fell into those specs, one thought was the bearing spinning on the spindle. I have done wheel jobs many times and never encountered this problem, the only thing I can think that would cause this is the races not being seated fully, I pressed them in so that does not seam logical but likely, the only two items that have not been replaced are the spindles and drums, Maybe the drums are not machined correctly and the races are not sitting parallel. I have never had to retighten wheel bearings once adjusted. Any thoughts on how a correctly adjusted bearing could possibly loosen up this much.

asked by: Mark K

Expert Reply:

It sounds like the problem you are having is related to one of the possibilities you have mentioned. It is nearly impossible to press a race in straight at home unless you have the proper equipment and have done it before. Taking the drums to a brake shop might be the best option to make sure the races are seated properly.

If they are seated properly then it is possible that the hub bore could be off causing the races to get out of position. The solution would be to replace the drums.

If the spindle is scuffed, marred, scraped, or otherwise damaged then that could also be the issue and cause the bearings to move around outside of tolerance. If the spindles are not damaged then the only other thing I can think of for the spindles is if they are bent from being overloaded. this would cause the bearings not to seat properly.

When we install new hubs or bearings our installers will tighten the castle nuts then back it off, tighten the castle nuts again, and back them off, and so on to make sure the play is taking out. Then they back it off one notch.

If you determine the drums to be the issue and want to replace them we have numerous options depending on what you need exactly. I have included a link to the hub and drum assemblies we carry that take the same bearings as your existing drums.

expert reply by: Michael H