drums won't fit over hub over Moser axles

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440BelII

440BelII

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I picked up some used Moser axles to use in my 8 3/4 rear on my Demon. The drums will not go over the center hub. I measure the axle hub at 3 inches. The drum register is measured at 2.83 inches.Has anybody run into this issue and have an idea of how to solve this problem???
 
I've never had the issue but I don't think it's too difficult to fix. You're only talking about 0.17". I would measure it with a pair of calipers to get as close to exact as you can and just have the drum milled to match. You may not even have to do that. May can just use a die grinder with cutting bits to rough it and a cartridge roll to make it pretty. Take it slow and test fit often and it should be fine.
 
Pop the studs out and send it to machine shop to be turned down. Pretty easy. Did you test fit the bolt pattern? They are not shortened truck pattern are they?
 
If Moser axles are like Strange axles, you can change out the axle register, I did mine.
 
Whatever way you resolve this, do not use a die grinder to enlarge the drum or cut down the register on the axle. The register is what keeps the drum centered, not the lugs. If you have to cut anything down do it on a lathe.
 
The register shouldn’t be 3”. Even all the large bolt pattern drums have smaller registers than that. If they’re new I would send them back. If they’re not new then take them to a machine shop.
 
Mopar Mike, I agree.I did text the person that I got the axles from.He was running disk brakes on his Duster. I was thinking that these axles are specific to disk brakes. If that's true,why do that and not just make them so they accept all brakes, whether disk or drum.
 
Small bolt pattern drums will not fit big bolt axles.

Drill the 4.5 pattern .

Cut the register.

And they still won't fit. You will need to find backing plates and drums for a big bolt car. The backing plates have a different offset and the axles have a larger dia. flange that the small bolt drum does not fit due to the taper. You can drill your small bolt drums if you use redrilled small bolt axles. Again small bolt drums do not fit big bolt axles. Register or flange?
 
These are big bolt pattern drums that I'm trying to use. When I bought the car, It had redrilled axles in the rear.My son will be racing this car and when these axles came about, we boiught them. It never dawned on me to check that the dums would fit, just took that for granted .
 
Oldmanmopar said:
Small bolt pattern drums will not fit big bolt axles.

Drill the 4.5 pattern .

Cut the register.

And they still won't fit. You will need to find backing plates and drums for a big bolt car. The backing plates have a different offset and the axles have a larger dia. flange that the small bolt drum does not fit due to the taper. You can drill your small bolt drums if you use redrilled small bolt axles. Again small bolt drums do not fit big bolt axles. Register or flange?
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He gave the axle register diameter at 3”, which won’t fit any of the OE drums, small or large bolt pattern. And the 2.83” drum register is for a BBP drum. The SBP register is smaller than that.

440BelII said:
These are big bolt pattern drums that I'm trying to use. When I bought the car, It had redrilled axles in the rear.My son will be racing this car and when these axles came about, we boiught them. It never dawned on me to check that the dums would fit, just took that for granted .
Click to expand...

You should have been able to take that for granted. All of the mopar disk kits I’m aware of will fit the stock axle registers.

Sounds to me like you ran into a custom set up, those axles wouldn’t be off the shelf for a Mopar. And that does raise the additional question of whether or not the axle flange stand off will be correct for any OE mopar drum.

Is there a part number on those axles anywhere? Moser should be able to give you that info if you can identify the axles.
 
440BelII said:
The bolt pattern is 4 1/2 inch, so they aren't truck axles. I don't see anywhere to change the register on these axles.
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Says who? Some half tons came with 4.5" bolt pattern.
 
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The more correct way to do this is remove the studs and have the axle hub turned down.
 
The caliper readings came out blurry. Here's what I have. The axle hub actually comes out to 3.1 when I put the caliper on it.
 
440BelII said:
View attachment 1715549230 View attachment 1715549231 View attachment 1715549232 View attachment 1715549233
Click to expand...

I believe you bud, those are BBP mopar drums.

The problem is the Mosers can be anything if they’re custom. Like Moser sells Mopar axles that have the axle flange offset of a SBP axle, but with the BBP. It’s lame, because you think you have BBP axles but then none of the BBP drums fit and you have to use re-drilled SBP drums.

I would call Moser and give them that number and see what they can tell you.


RustyRatRod said:
The more correct way to do this is remove the studs and have the axle hub turned down.
Click to expand...

Yeah but that only works if they actually have the Mopar BBP axle flange offset. They may not. They could have a Ford offset for all we know because they were ordered for that disk brake kit.

He could pay to have the axle register turned down and find out the drums STILL don’t work because the axle flange stand-off is wrong.
 
Dr Diff, thanks the reply.Without buying different axles, what are my options ? I've had people tell me to cut the axle hub on a lathe and others say open up the drum register.We talked to a local street rod builder and he said that this is a common problem on Ford 9 inch rear ends when going to higher strength rear axles.He said that he opens up the drum register.
 
That depends.

That is the overall length of the axles?

What is the distance from the snap-ring on the Green wheel bearing to the outside edge of the axle flange?

Cass
 
I come up with 2 3/8 inches.I put one axle in the housing and it looks like if I could get the drums on, everything else is good.
 
2.4" from the snap-ring to the outside edge of the axle flange is the correct dimension for B/E body brakes. I assume you are installing these in an OEM A-body housing.

Do the axles measure 28" overall? If so, I would machine the brake register to fit the drum (2.830").
 
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