The Stovebolt Site Forums The Parking Lot Big Bolts 1946 2 Ton Rear Axle Flange Bolts

My son's rear axle bolts tend to slowly loosen up.
I put on lock washers and that has greatly reduced
the problem but not eliminated it. Bolts are torqued
to 90 Ft Lb.

My thought is that over time with the rear drums being
R & R'd that the threads on those bolts are worn. Being
bolt thread to hub thread friction is what keeps the
bolts from loosening up that it is possible the
threads on the original bolts are worn so they do not
stay tight.

Solution then would be to install new axel flange
bolts.

Everyones thoughts about my theory. Jeffrey

Are the '46 wheels hub piloted like the '47 on?
If so make sure that the center holes fit snugly on the hub.
If you have a loose fit due to wear or most likely someone filing rust out of the holes and sanding down the hubs so that they "come off easier", the movement of the wheels around the hub will loosen the bolts.

The hubs center the wheel for there are no tapered lug
nuts as on modern cars and trucks.

Well if the hubs are worn there is no fix then. But when
we went over the truck I did not notice excessive play when
I had the wheels off.

Though this is my first 2 ton Art Deco that I ever worked
on. No AD or other 2 ton truck or hub centered wheel truck
before this 1946.

I guess I will have to keep checking those bolts once a week
for now. Jeffrey

Hy 32vld, way back when when I was learning about vehicle maintenance my instructor brought up the subject of the different "class of fit" for some fasteners. The subject he brought up was the relationship of the fit between a wheel retaining nut and the stud/bolt it was installed on. He went on to say that the fit between the two components was more precise than the standard nut and bolt and that when trying to assemble by hand you might find it difficult to get the two components together. He taught us to never use lube of any kind when installing any type of wheel nut or bolt and never use a standard tap or die to clean the threads as this would destroy the precise fit between the parts. This advice has always stayed with me, and I have replaced many studs and nuts when the fit became loose to any degree, hope that helps.

Easy way to make sure the hubs are good is to mic them.
I believe that the number is 4.750 with a 0.005 tolerance. If they are good, replace the wheels. Yes that is a big deal, but the problem is only going to get worse.
With no centering, the wheels will loosen quickly. And when they do, not only are they moving up and down relative to the hubs, but they are rotating back and forth every time you step on the gas or brake. Essentially the wheels are slamming back and forth into the fasteners. They can wear or sheer off studs/bolts. This also ovals the holes in the wheels so they move more and slam harder and wear more.........
Very Not Safe.
Check the fronts as well, they could be fine, or wheels could have been moved around so all are suspect.

The lug nuts are not loosening, it is the axle flange bolts.
Jeffrey

My bad, read that wrong.

Jeffrey,

I would try using some new axle shaft bolts. It should be a relatively inexpensive experiment anyway. Make sure the bolts have the correct shank height where they contact the axle shaft flange. Originally there was a axle flange bolt lock plate used on these trucks. Lock plates show up on ebay occasionally.

Paul

Paul, my son's truck had those lock plates but all the
tabs had broken off due to many times of them being
bent up and down.

I never thought of using ebay so thank you for that tip.
Jeffrey

As a former Air Force tech, I can't help but think that safety wire could help you out as well. It's a bit of an art form, but it's also a period correct technique.

Safety wired bolts

If the raised surface that a tapered nut entered are destroyed, perhaps the wrong nuts were used plus someone with an impact wrench used it improperly.

If the studs are not rigid, it is time to get new 9/16(the next size larger) bolts, use a carefully sharpened(new if possible) 9/16 drill bit, and use a milling machine, or at least a drill press to make the holes are straight and vertical. This is not the time to do it on the cheap. Before you do any drilling, get the proper bolts as stated above, and proper nuts, either flat or tapered.

This works well if your 9/16 bolts are hogged out, to use 5/8 bolts, just make sure the mounting holes in the wheel are proper size. I had to use 5/8 bolts on my '95 GMC, drove the dealer nuts, me too, trying to find someone who knew what a dimension was, rather than VIN. Have 5/8 PN somewhere if someone has a need.

Ed

Red Loctite is your friend. Use brake cleaner or carb cleaner to get the threads in the hub and the bolts squeaky clean, and put a drop or two of Loctite on them as you assemble things. The red color is designed for "permanent" installations, so it might be necessary to heat the bolt heads to about 300 degrees with a torch the next time you want to remove the axles.
Jerry