Wheel nut torque

[Bob]

Repacked the wheel bearings on my Mac 25 trailer (purchased last summer)and noted that the nuts were on hand tight. I took the first one off with a wrench, but it seemed so loose I tried the other by hand and sure enough, it came off. Niether side had any noticable play and I've got a substantial grip, but I'm planing on some long roadtrips this summer and don't want to find out I screwed up a long way from home. So my question to the group is: how much torque should I use on the wheels?or... should I do the drag method with a fishing scale? if so, how many pounds of drag to turn it by a lug?

 

[Bob]

Which Nuts?

I think you might be referring to the bearing hub nuts rather than the wheel lug nuts. Lug nuts are torqued up like normal wheels on any vehicle, but the big hub nut (one on each wheel) in the center is generally pretty close to finger tight. When repacking and replacing bearings, you want to "seat" them snugly, then back off just a little on the nut so that they can roll freely. It is better to have just a little bit of free play than to have tension on them. As you tighten the hub nut, spin the wheel by hand and you will feel its resistance increase when the bearings start to bind - back off just a little til the wheel spins with noticeably less resistance, and they will be about right. You definitely DO NOT want to torque them up to wheel lug specs - that would pulverize the bearings in short order. Make sure each one has a castellated nut or castellated cover with a cotter, or some other locking device so that once you have set them, they won't back off. Once the wheel is mounted and everything is set to go, pull in and out on the circumference of the tire - there should be zero to very slight free play, but the wheel should spin relatively freely. When you have driven several miles, stop and feel the outside of the bearing hub with your hand - it can feel a little warm, but if it is hot you need to check it out.

 

[Bob]

Bearing nuts

You're right, the wheels aren't the issue, it's the preload on the bearings that I am concerned with. Some cars have torque specs and some say to seat them and then back off until it takes 5# or so of pressure to turn the wheel (measured by hooking a fishing type scale to a lug). Too loose or too tight and the bearings will wear prematurly. I'm looking for an objective way to measure the tightness.