Not another pinion shaft nut thread...

So I finally got that electric impact wrench I've been wanting for so long. 1/2" drive, 240 foot-pounds, all that. Vroomp!

Then I decided to check the FSM. The shaft nut needs to be torqued to "between 200 and 220 foot-pounds." Hm... my wrench is a 240.

And then it turned out that TorqueStix doesn't make anything above 140. /facepalm

Anyone got an idea for making sure I don't over-torque the nut? Or does it really matter? Also, will I need to use a yoke immobilizer with an impact wrench like I would using a breaker bar?

 

"will I need to use a yoke immobilizer"

Not with the impact wrench. But I take the wrench ratings with a grain of salt. I doubt you will over torque your nut.

 

Ok, cool. Thanks. I'm still planning on replacing that damn broken yoke, and hopefully this month.

 

DO NOT USE AN IMPACT WRENCH TO TORQUE ANYTHING!!!
Use a torque wrench. Pure and simple. Just because an impact is rated for a certain torque doesn't mean that's where it will torque something. Many variables involved. I can't say it enough, use a quality torque wrench!


Sent from my iPhone

 

Nickmil is absolutely right, of course.

That said, torque values are only a guideline or estimate. In the real world, the ACTUAL residual tensile stress in a fastener torqued to a certain value can vary by 100% or more depending on the use and type of lubricant, the fit or condition of the threads, and numerous other factors. That's why truly critical applications are measured in other ways, such as elastic deformation (stretch).

At 220 ft lbs that leaves considerable leeway, and while it is always good to do things right, a jeep pinion shaft is not a swiss watch or a Mars lander. IMHO. 1940's technology was built to a different philosophy than today's computer-tech world.

You may want to borrow a "torque multiplier" wrench from a truck shop. Or use a long breaker bar (or cheater pipe) and estimate the pounds you are pulling, times the length. (e.g. 220 ft/lbs = 2ft. bar x 110lbs. Or 4ft bar x 55lbs.)

Or run the yoke you have.

 

I hear that. I can remember someone talking about how the Colt 1911s and their replicas were so good because they were made to "watchmaker specifications." Only they weren't; WW2-era 1911s could do double duty as a pair of maracas with all the rattles they have in them.