axle mounting bolt torque

[retrocar66]

Is there a proper torque for axle mounting bolts? If I mount my new axles with a 1/2" air wrench that can go to about 400-450ft lbs, is that enough?

Also, I'm not sure the new axles will come with mounting hardware. Is grade 5 sufficient for this application, or do I need grade 8.

[Inland RV Center, In]

Originally Posted by retrocar66

Is there a proper torque for axle mounting bolts? If I mount my new axles with a 1/2" air wrench that can go to about 400-450ft lbs, is that enough?

Also, I'm not sure the new axles will come with mounting hardware. Is grade 5 sufficient for this application, or do I need grade 8.

Grade 5 is OK, but grade 8 is far superior.

We have supplied the grade 8, for many years.

Andy

[TG Twinkie]

There are tables on the Internet showing the torque specs for each grade of bolts. 450 ft pounds is way too much for a 5/8" bolt. Grade 8 bolts are recommended.

[Shacksman]

Here's a chart on this page for torque specs for axle mounting, from Dexter.

Suspension Maintenance for Trailers

[Aviator]

Definitely go grade 8

[putback]

Grade 8....Clean the mating surfaces. If you use lock washers use highest quality. Finish tighten with a breaker bar if you don't torque. Above all else check them at least once after a few miles.