Redrilling Brake drums for 4.5" bolt pattern

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MileHighDart

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Can this be done at home ?

I'll probably be sending my axles out this week to Moser to have them drilled for 4.5" bolt pattern and new studs put in.

But my question is about the drums. Moser can redrill them for $60, which is fine, but add $66 shipping to get them there and back, and thats $126 just to have the bolt pattern redrilled.
Can I redrill the drums at home ? Seems by setting the drum on the end of the axle, with the drum being hub centric on the axle that it would be easy enough to mark the drum for the new pattern. Are the drums hardened steel ? Will I be able to drill it myself on a drill press ?

Anyone ?
 
MileHighDart said:
Can this be done at home ?

I'll probably be sending my axles out this week to Moser to have them drilled for 4.5" bolt pattern and new studs put in.

But my question is about the drums. Moser can redrill them for $60, which is fine, but add $66 shipping to get them there and back, and thats $126 just to have the bolt pattern redrilled.
Can I redrill the drums at home ? Seems by setting the drum on the end of the axle, with the drum being hub centric on the axle that it would be easy enough to mark the drum for the new pattern. Are the drums hardened steel ? Will I be able to drill it myself on a drill press ?

Anyone ?
Click to expand...

Whats moser charging you for the axels.
 
I have Strange axles. Putting the car back together, for some reason, I used the 4 3/4 pattern drilled in the hub, thinking Chevy rims are cheaper. Then looked at my 4 1/2 drums. Poop. Then took them to a local machine shop, with a template I copied, and asked, since the hub is self centering, can we just elongate? $30.
 
I did just what your asking on mine. I made the template, marked the drums and used a good bit with just a hand drill and they work perfectly. I'm sure with the drill press your results will be the same. Drums are not hardened. Just make sure your bit does not walk and you will be fine.
 
Why not go buy the proper drums.....what are they 10" diamater by 1.75 or 2 inches wide or so? Can't see them being much more that $80.00/pr. New is good.......
You might have the holes elongated, and it might center on the register - but I think it possible there will be a little slippage ( I know, the wheel should sandwich it all in place) causing a possible "clunk" noise on application or worse there will be "chatter" on high speed application if it does go out of round (think wet roads etc...)
If you're bucks down then it might be a temporary solution to elongate, but I don't see good coming from it in the long run. If the factory didn't take the short cut then maybe rethink the idea........
Daryl
 
my drum are drilled now //didnt weld anything up on them just turned the drum to it had new metal and drilled . not a problem yet=D> been that way for some time now..had a set off stock axles drilled also no problem there either...and they have been 6.20 in the 1/8 mile i think 1.3x 60' with wheels in the air
 
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One way to get the drums caught up with your axles is to use one of the axles as a pattern for the drums.

Ask the guy doing your axles not to install studs in one of the axles.

Then use a transfer punch to mark just one of the holes, center drill and drill for a size that will allow for a clean bolt to be installed lock it down without it shifting one way or another.

Next pick a hole about opposite to the first one, and transfer punch it, center drill, drill, and put a bolt there and snug it up.

When you have three done it's safe to transfer punch the last two at the same time and finish them off.

When you are done you may want to take a single pass thru those holes with a drill or reamer that closely resembles the factory holes that are present, these holes tend to have a bit more clearance than average.

Or,... If you can get an axle that has the pattern you need, and can manage to get it to jive with the center hole in your drums, use it.

A scrap axle is fine, cut it short, use it, and keep it as a drill fixture.



Transfer Punches


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When I went looking for a picture of transfer punches a photo of a brake drum came up in the search.

It was a Jeep forum here is his story.................

"Anyway, I tried to find a machine shop to drill my drums out for the new pattern, but most wanted $100 or more to drill them. I figured what the heck, I can do it. So I bought a set of transfer punches, borrowed my friends drill press, and boom, dual drilled brake drums".

http://www.jeepforum.com/forum/f11/bolt-high-pinion-dana-44-a-747194/index4.html



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If you have any questions let me know, I'm happy to help.

Double check that the set you are looking at has the size you need, some sets stop at 1/2"

Some searching may show you can order the one size you need, consider getting a set, not much cost, and it pays for it's self every time you use it.

"A Giant Time Saver"

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You know........... I am really holding back right now............

Not to say something.


So let me say this........

If you are going to elongate the existing holes,.... send the drums to me and I will do them for free.

If I can afford it I will even pay for the return shipping.

Please don't let some Jeep guy show up an A body guy.
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Machineman, thanks for the tip about the transfer punch. I was planning on using the redrilled axle as a pattern, just was going to mark through the holes then center punch them and drill. But after seeing the transfer punch's, I think thats the way to go.

Thanks for the tip.
 
I just redrilled my drums a couple days ago.


I made myself a transfer punch. Center punched for all the new holes, and started drilling, first with a small 1/8" bit, then moved up to the 1/2" bit. ( 1/2" lug bolts, I figured 1/2" holes, wrong)

First mistake was not looking closely enough at my new moser axles. The studs they installed have a shoulder on them that protrudes from the face of the axle flange about 1/8". This part of the stud is actually 5/8". So I had to redrill the first drum with a 5/8" bit.
Then second drum I started with the small bit and then went to the 5/8".
Worked fine. There was a couple holes where the drill bit may have walked a little, but just touched up those holes with a rat-tail file and I was good to go. The drums fit perfectly onto the new axles. Center register and the lug bolt holes all match up fine !
 
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