Anyone know anything about Stemco Pro-Torq axle nuts?

.001" to .003" for me.

 

Ok, maybe it is time to have a good look at the spindles. Is the bottom of the spindles worn from the bearings being loose, and this is why you can't get a proper adjustment? Have are real good look at the threads too. You may have worn threads and the nut is locking up on the actual threads, not from holding the bearing in place! If your threads are causing 100 ftlbs of turning friction, that means only 100 ftlbs are left for bearing setting during that step. Thread the nut on to the spindle with no bearing and see if it turns nice all the way!

 

That's a good point and entirely possible that the threads could be worn out. I think he said he's running dayton wheels so that means everytime he has to do brakes the bearings are coming off as well.

 

I've seen a few like that and they replaced them for free. I believe they had a run a few years ago that were not hardened correctly. Personally, I'd change the bearings/cones, double check the spindle and get a new nut.

I always shoot for 0.001-0.002" end play with used bearings. With brand new bearings, I set them to zero hand tight, once things settle in, they end up at 0.001-0.002".

 

Interesting to see all the different methods used to set bearing play. I've always spun the wheel, run them up, backed them off then gradually tightened until I could feel zero play and minimal drag. Then installed the locking nuts and keepers.

 

That's exactly how I do it.
I'm picking up 4 new nuts today. Stemco engineering dept replied to my email and asked for pics

 

X2. I have had this problem a couple of times

 

It would be nice to know if Stemco admitted a problem or if the hardening is just an assumption. I waited to reply because I know my method is a bit out of any recommendations I recall.
Also the inner bearing race can wear a grove on the outer edge of the seal area. A new bearing may not fall in the wear pattern the same as the old one. This could wear away quickly resulting in loose bearings. Use a file or something and get rid of the rough stuff.
If you are running heavy on that 3720 212047 or 212049 compo that clearance is mandatory. Use real synthetic oil and there is a replacement for that 3720 with an extra roller or two, don't remember the number, but it helps.
Preload on tapered roller bearings also helps maintain alignment of the rollers between the inner and outer races.
Most of that said just to reply to other peoples good post and I thank all of you. Now I will ad a card in this house of cards and wish everyone the best of luck. If you are having a problem and keep doing the same thing the same way you will usually keep having the same problem. Those 212047 and larger bearings can have 25 ft lbs preload and run. Just my experience, try 15 if you feel better.
He does all of his bearings the same and the only ones he has a problem with are on the dolly, it bounces. The only thing I can thank of a little slack in adjustment is hammering the metal away like a stone mason.

 

When I worked at Conway Freight, they wanted 50 ft/lbs of preload on drives, and 25 ft/lbs. on steers. Which went against the 0.001-0.005" end play that bearing manufacturers want. I've seen then done with dial indicator to have end play, I've seen them done a certain torque, the back up 1 flat. I've seen at least 1/2 dozen different ways from good mechanics and have not seen any way more or less prone to failures.

My conclusion is, it's not as critical as most people make it out to be. I even took a Con-Met course on the preset hubs and the guy said that spec is 0.001-0.005", but zero is OK if it doesn't drag. Well then why do you say 0.001" minimum of zero is OK?

I go for 0.001-0.002", I have seen ABS set faults for erratic signal at 0.005" on trailers, so loose is bad. I never seen issues at Conway running 50 ft/lbs of preload, which I thought would build excess heat, but I never seen an issue from it. So if how you've always done it is working for you, it's not wrong.

 

On inner and outer nut set ups are y'all checking that before and or after installing the jam nut?