The TMC process is the way I've always done it. This explains it better than I can...
https://www.anythingtruck.com/commercial/740-wheel_bearing_adjustment.pdf
Hub removal on the trailer to change s-cam.
Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by nikmirbre, Mar 13, 2025.
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Oxbow, nikmirbre, Rideandrepair and 1 other person Thank this.
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What often happens is when tightening the outer nut, the inner gets over tightened. The reason being the inner nuts threads have gotten sloppy over the years. I did all 4 drives on mine. Followed the procedure exactly as written. I used a cheap harbor freight dial indicator to check them. 1 was too loose. Surprised me. Worth the effort. I like this Timken chart. I think they came up with the “standard procedure” because everyone does them differently. I’ve had 2 burn up because of people’s personal procedures, over tightened them. The dial indicator takes the guess work out. Lets you check your work.
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Since this work has been done, my hub has been running pretty hot..... im gonna have to go to the trailer shop Monday morning. I did stop by TA last week and had them torque the nuts to spec. He couldnt get the outer nut off it was so tight. I thought that would solve the issue. the hub is warm enough to where after I driver for a while, Ill get out and touch the hub and cant keep my hand on it cause its so warm. Im gonna have them remove the wheel and use a dial indicator or whatever they have to do to loosen up the hub. I think I said prior that when the guy got done tightening everything, it was a little tight in turning.
I need it loose, make the hub easier to turn. Should something be done to the bearings prior to re-install... should bearings be wiped clean and pour hub oil on them prior to install?Rideandrepair and Oxbow Thank this. -
If they've been running that hot I would 100% be inspecting them and not just readjusting the end play.
IH Truck Guy, Rideandrepair, lester and 2 others Thank this. -
Ok, id probably replace anyways as its not really any extra labor involved. Bearings aren't expensive...Rideandrepair Thanks this. -
When tightening the hub make sure to spin it. Otherwise it can flat spot a roller.
IH Truck Guy, Oxbow, Rideandrepair and 1 other person Thank this. -
Pick up a infrared temp gun. It can be used for many things.
Oxbow, Rideandrepair, JB7 and 1 other person Thank this. -
Yea I have one but, I kept forgetting to get batteries for it. I know its never supposed to be that hot though.Rideandrepair Thanks this. -
You can just loosen it up yourself. At this point the shops are just going to keep guessing, and probably screw it up again, and of course you pay them. You have the torque wrench, sockets. Jack it up. Spin the wheel, get a feel for it. Loosen the outer, the inner should be hand loose. If not, it’s definitely too tight. Don’t spin the wheel, everything is already seated good. Chances are it will be hand loose, but the threads are sloppy. That’s why it’s gets too tight when you crank down the outside big nut. So, Back the inner off 1/6 of a turn.( 1 flat on the nut) Reinstall and torque the outer. Should fix the problem. If it’s still hard to spin, after torquing the outer, back the inner off another 1/6 turn. That will most definitely do the trick. You’re looking for the final result. Common sense says if you just snug the inner by hand, and torque the outer, should be good. But because the outer takes up any slop in the inner nut, it ends up being too tight. So backing off the inner a flat or two makes it all work out. Worst thing that will happen if it’s a bit loose, is premature seal failure. Bearings will run on the outer portions. Over time, you can see the wear marks on them. Not ideal. But on the other hand, if too tight, they get hot, and fail, seize up, destroy spindles, come completely off sometimes. Potential Disaster. People claim it’s impossible to feel end play. Not true. With the wheels mounted, you can wiggle the tires/rim, and barely feel it sometimes. Maybe not in a perfect world, if it’s exactly pre loaded/ torqued. But feeling a tiny amount of end play is fine. Better than none at all when guessing. Keep in mind, the rollers are meant to run perfectly on the races. The cage shouldn’t be in any contact with the rollers. Getting the torque set right, the cage just floats doesn’t contact the rollers at all. When a bearings failing, you can often find shavings, small pieces, just by sticking your finger into the hub cap, all the way to the bottom. Catch it before a disaster happens. So now- Take the hub cap off, look for metal, just in case, loosen the inner, retorque the outer. Good to go. That’s all you need to do at this point. I suggest jacking up both axles on that side. Compare the one your working on to the other one. See how they spin freely. You’ll get familiar and be able to insure its correct. You already know more than the average TA Goober Mechanic. Don’t give up now. Lol. At least you can avoid problems in the future, making sure anyone replacing a wheel seal out on the road always torque your hubs correctly. My steer failed 30 days after a seal replacement. Ruined the spindle. Luckily Saps Brothers stood behind their mistake. Since then, I do my own. On a side note, I.don’t think replacing a seal should cause a warmer hub. New bearings maybe , just a bit, for a short break in period. But not just a seal, re using bearings. You mentioned having bearings replaced. They’re cheap, but also need to replace races in hub. That’s more labor costs. I wouldn’t bother. They’re probably still fine. In the future, when doing work, price bearings, and price hub set. Hub set comes with new hub, bearings, races already installed. Makes things easier. Especially on fronts. Being aluminum, they often get worn and races will spin. T/A won’t replace races on aluminum hubs. I’ve replaced mine. No big deal. Afterwards I regret not just replacing with whole hub kits, cost for parts wasn’t much more. Recently did races bearings seals on my drives. Had a rough time changing races. Anyway the big money saved on labor goes a long way towards parts. All adds up to a better end result.
Last edited: Mar 30, 2025
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