I am getting readdy to assemble the hubs, drums and bearing on the 54 F-750 and was reading something from Timken bearings about torqueing the jam nut to 275 Ft lbs.

I dont have access to a torque wrench that big. How can we simulate that kind of torque. They give a torque chart from about 250 to 400 ft lbs , depending on what size nut and thread count. It appears the someone in the past used a chizle to smack it tight.

Thanks,

JimG

 

Have you considered renting a torque multiplier? They are like a rachet but instead of the direction switch you put your torque wrench there. They have a 4:1 gear ratio so even if your torque wrench only does 150 ft-lbs, you can put 600 ft-lbs to the nut. They are fairly cheap to buy also. I can get one for $90 CDN.

Depending how bad it has been chiseled you may want to replace the nut.

 

Just a thought if you know anyone in the building trades. years ago I had a need for one working on an old Freightliner turned out my father in law had one. he was an iron worker and they used one in the erection of steel on many of the jobs. just a thought.

 

The autozone here loans out a 1/2 torque wrench that goes to 300 ftlbs.

Or you can divide 275ft-lbs by your weight and that will tell you the distance (in ft) from the center of the socket that you need to put all your weight on

 

Is this 275 ft-lbs spec from Ford, for your specific vehicle, or a generic value Timken has for "some" applications?

Also, if it is just for the jam nut, not the primary nut, that is a completely different game. You'll need to hold the primary while tightening the jam nut against the primary. Hard to imagine how you could achieve that. Sounds like they are just saying, "the jam nut needs to be real tight".

 

Thanks guys for all the great assist regarding the axle jam nut and torqe.
51 Duller, I had never heard of a torque multiplier. what a neat idea. Minger, went to auto zone, they will lend me a torque that goes up to 250.
AlbuqF1, this was a general spec by Timken for bearing assemblies.
On this particular Ford, this is how the rear bearing is set up

Tha adjusting nut has a tit on it, the lock washer has a tine that fits into the grove on the axle. It also has holes all around it. The tit of the adjusting nut will fit into the hole of the lock washer. (therefore, the adjusting nut cant move) The jam nut now torques against it. My Ford manual does not give specific torques for this arraingement, but mearly states to tighten the jam nut.

I really appreciate all the help

JimG

 

I can't believe with the setup you have that the jam nut needs anything special in the way of torque, especially with the locking washer arrangement. 60 - 70 ft-lbs would be fine IMO.