Anyone know anything about Stemco Pro-Torq axle nuts?

I always torque my outer nut and check it with a dial indicator. Really starts getting old if you have to adjust it more than like 2 times. lol

 

50 ft lbs of torque are these the bearings with the inserts? Con met? I do not see regular bearings lasting long like that. In fact I had a failure because of exactly that.

When it comes to bearings here's what I do: *EXACTLY* as the OEM recommends. You've just been involved in a fatal wreck where a bearing failed and a wheel killed someone. The OEM says you didn't install them correctly, but you know you did a good job. However in your defence what sounds better?

"Sir I installed them how a mechanic online recommended"

or

"Sir I installed them how the parts guy at the dealer recommended"

or

"Sir I followed the OEM recommendations exactly and had the instructions in front of me during install"

You could have a "trick" way of installing them for 30 years. But in the court that doesn't count for jack ####!

 

I have a sheet from an OEM bearing installer that says 0 end play but 0 preload is where a bearing will last the longest. The problem is that it is impossible to achieve because you cannot measure it. It's also hard to adjust things that fine even with a pro torq nut. That's why I always do .001 but below .002. Dial indicator every single time.

 

Not Con-met preset, that was regular old school bearings with a pro-torque and I felt the same way, but it worked just fine for them. I'm not saying it was right, I'm saying that's what they did and they had no issues from it. They even had that printed in their maintenance manual. The preset hubs got 350 ft/lbs on the inner nut. If it wasn't pre-set, it got 50 ft/lbs on drive and trailer, 25 ft/lbs on steers (the manual also clear stated (no back off).

I do it pretty much the same as you, 0.001-0.002" is my comfort zone. That's for the legal reasons that you mentioned, I follow the "correct" procedures. But, it's really not as critical as most people make it out to be. A little preload is not harmful, in almost every other application there is preload in a tapered bearing.

You can dig up contradictory info from every bearing manfacturer. SKF recommends end-play, but will tell you how good a little preload is.

http://www.skf.com/us/products/bear...ng-preload/effects-bearing-prelaod/index.html

If you follow the links to the preload chart, negative 1/2 thou is the best bearing life. How many ft/lbs that is, I don't know. Guessing that 25-50 ft/lbs was only a 1/16 or so of a turn, I'd guess it's what Conway worked out with Timken.

 

I know this thread is old, but whatever ended up happening @Ozdriver ? Did the problem go away? Did Stemco ever analyze the old Pro-Torque nuts and make any determination?