9" axle shaft specs

[crazi429]

Hello everyone long time since I posted here but I am hoping to get a answer. 9" big bearing axles have 3 different applications 66 to 75, 74 75 and 76 77. I know it's due to different brakes but what are the actual measured difference. I attached a 76 77 picture. Looks like 3 1/8 bearing to flange and the 71 Moser I just ordered was 2 5/8. So trying to figure out the 74 75.

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[garberz]

66-75 (SMALL BRG) (28 SPLINE) 2 1/2" BRAKE R.H..29.62"
66-75 (SMALL BRG) (28 SPLINE) 2 1/2" BRAKE L.H..27.25"

66-75 (LARGE BRG) (28 SPLINE) 1 3/4" BRAKE R.H..29.31"
66-75 (LARGE BRG) (28 SPLINE) 1 3/4" BRAKE L.H..26.94"

74-75 (LARGE BRG) (28 SPLINE) 2 1/2" BRAKE R.H..29.75"
74-75 (LARGE BRG) (28 SPLINE) 2 1/2" BRAKE L.H..27.25"

76-77 (LARGE BRG) (28 SPLINE) 2 1/4" BRAKE R.H..29.68"
76-77 (LARGE BRG) (28 SPLINE) 2 1/4" BRAKE L.H..27.25"


Mark

 

[garberz]

There’s more info in this thread.

https://classicbroncos.com/forums/showthread.php?t=254278&highlight=axle+lengths

Mark

 

[DirtDonk]

Since you're using an aftermarket company like Moser too, I would verify how THEY measure their offset.
Some use one side of the flange, some use the other. Some use the back of the bearing like you are in your first pic, while others (like us) use the front face of the bearing.
Brake companies like Wilwood might use a different method as well.

Helps to be apples-to-apples.

Paul

 

[crazi429]

This is why I would love to find drawing showing how the 3 different axle are different. I asked when I picked up my axle and was told by Moser they didn't have any drawing. But then how do they know how to make them to stock specs.

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[crazi429]

Thanks just the info I needed just couldn't open link on my phone.

 

[SteveL]

Does wh have it on the website. I think they did in the print catalog

 

[DirtDonk]

I thought we did too. Don't see it at the moment though, so maybe it got moved.

Let you know if I can find it again.

Paul

 

[Broncobowsher]

I thought it was the WMS to the brake backing plate, not the backside of the bearing. Basicly how wide of a brake shoe will fit.

Best is to get the instructions (in detail) from the axle builder. I want to say the bearing retainer is a stable measuring point to both the WMS and the end of splines.

 

[DirtDonk]

Yeah, all of our charts use the wheel mounting flange to the backside of the bearing.
So definitely best to see what they're using.

According to our way though, your axle has the correct 3 1/8" offset for a '74 and '75 "medium duty" bearing setup.

Paul