Hot Rods Axle Studs

Hi, I purchased new drums for my rear axles (Hot Rod Works) and the part of the studs that the drum goes on is too small. Does any body know the correct Dorman # to order ?

 

We can guess what you're working on, or maybe you give us a few hints?

 

Does it matter, the center hole of the drum should fit the axle pilot to center it and once the lug nuts are tightened the drum will be locked down.

 

I am working on a 38 read end with a Hot Rod Works setup. This setup has a slide in axle with a wheel bearing like a 9" ford and a 5 x 5 1/2 stud spacing. The drums I got are for 40 - 48 ford with 5 x 5 1\2 wheel but the studs are not the same diameter as the drums. ?

 

I.m running a '47 Banjo from a truck--Open Drive (2 year only ) sounds like you will have a great set up.

 

It's a good set up but I am not happy with the studs not being the same diameter as the drums.

 

Best thing to do is to measure the studs (length of threads, knurl and over all length), go to the Dorman catalog online that has the stud sizes and choose one that will fit. If the drum is too small you can ream out the holes to fit.

 

I did that and my head is still spinning. I thought that some body on here had the same experience it would save me some head aches. Thanks Jim T.

 

Can you post a picture of the two together.


I'll look at mine when I get home. I have the same set up (original drums) but it isn't together yet.

 

But, does the center hole of the drum register tightly on the axle's center? If it does, the drum will stay concentric and the studs shouldn't really matter after you tighten on the wheel.

 

Have you contacted Hot Rod Works about your issue? Seems to me they would/should know?

 

No one is going to like this but I am going to say it anyway. If the studs are too big a drill will make them fit. Most Ford studs are 1/2" diameter so a 9/16 bit will get ya there. if the studs are smaller then the holes most drums have a larger hole then the stud anyway. The register (center sticky out doodad) will keep the drum in place and the wheel lugs will hold it tight to the axle.

Just a thought now go back to overthinking it.

 

this axle?



and this drum?

 

Yes they said they don't have any other studs'

 

Yes.

 

I don’t understand the problem.
The drums register off the center of the axle.
There should be some clearance in the holes for the studs.
Are the holes way oversized in the drums ?
They look like good drums,,,and the axle looks great too.

I’m lost.

Tommy

 

Hi Tommy please don't get lost ! Yes the holes in the drums are the size of the boss that goes through the axle flange. I can just let it clock and it will be ok but it bothers me to have the drums not slide on the studs. I feel if I back up and hit the brakes hard then step on it hard going forward it can either shear the studs or elongate the holes in the drums. It just isn't right.

 

The studs function is to provide, along with the wheel nuts, the clamping force of the wheel against the hub. That clamping is what keeps everything tight together. There should not be any stress on the sides of the studs. The kind of movement you're worrying about isn't going to happen unless the nuts are loose, in which case all bets are off as to what might happen!

Chris

 

I know but it just bothers me when it isn't right.

 

Then you haven't seen OEM done that way.

 

As a retired machinist, I've always thought like you, the clearance should only be enough to accomplish the job. Only two possible outcomes, you'll do whatever it takes to be satisfied or you will lower the bar (so to speak) on your expectations.

 

You could do an engineering analysis, to see how tight the lug nuts need to be to keep the drum from moving relative to the axle and wheel. You'll have to make an assumption about the coefficients of friction between the parts, and the maximum torque on the drum, which requires an assumption about the coefficient of friction between the tire and road, but the rest of it is pretty straightforward.

 

This is a classic example of overthinking.

OEMs have been using the arrangement you call "not right" with both drums and rotors, since swaging studs fell out of fashion. Literally hundreds of millions of vehicles have rolled the roads with this exact configuration.

If it were an issue, it would have surfaced by now, and it would have been legislated out of existence.

As has been mentioned, you need two things, and just those two things:

1. A center bore on a drum or rotor that snugly fits over the axle or hub register.

2. Properly torqued lug nuts, or lug bolts.

The "problem" that you are trying to correct does not exist.

 

Gimpy,

Swaging ,,,now that is a term I haven’t seen in a while,,,I’ll bet a lot people don’t even know what that is ?
The old days,,, not that you witnessed it,,,but certain you have heard of it.

Tommy

 

Jim, you left out compensation for "road crown".

 

That's not important.

 

Either the axle hole or studs

are they close ?

Use a brake cylinder hone to open them up and keep the hole round.
I’ve done this many times with aluminum wheels that don’t fit in the hub

 

I feel that theres no way that would ever cause your studs to sheer but if you let me borrow the vehicle in question I'll test that theory as long as your tires hold out. I'm here to help.

 

But....it IS right.......

Ray

 

For personal peace of mind no matter if it is or isn't an actual issue you might figure out some simple spacer rings to go around the studs to take up what slack you have. That would probably some thin slices of thin wall tubing that just slipped over the studs and took up the slack. Mean while most of us will just put our drums on, stick the wheel on and torque the lug nuts and call it a day.