Medium Duty/ Big Bearing axle questions

[Banjer Picker]

What are the lengths on the axle shafts for a medium duty (74-75) 9" rear end?
(A measurement from base of axle shaft to inside surface of bearing wud work too if you just have some laying around)

When upgrading to the extreme duty chromo axles w/ tapered bearings do you have to put a tapered race in where the axle seal used to be (to accommodate the different bearing style?)

How do the tapered bearings stay lubed?

 

[mattt]

 

[Viperwolf1]

66-75 (SMALL BRG,SMALL BRK) (28 SPLINE) 1 3/4" BRAKE R.H..29.62"
66-75 (SMALL BRG,SMALL BRK) (28 SPLINE) 1 3/4" BRAKE L.H..27.25"

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

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

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

You need to remove the old inboard seal. The bearing cup fits where the old bearing went. The tappered bearing gets lube from the axle tube (you removed the old seal). The new seal goes on the axle between the flange and the bearing.

 

[Banjer Picker]

Awesome info! This may be a dumb question but since there seems to be less than .5" difference in lengths; would all large bearing driver side (28 spline) axle shafts be interchangeable? (passenger side interchange w/ other BB pass sides too?)

Thanks!!

 

[Viperwolf1]

Awesome info! This may be a dumb question but since there seems to be less than .5" difference in lengths; would all large bearing driver side (28 spline) axle shafts be interchangeable? (passenger side interchange w/ other BB pass sides too?)

Thanks!!

No. The difference is going to be in the length between the bearing and the outside of the flange. This length needs to be correct to place the drum in the right place over the shoes.

 

[Banjer Picker]

Ahhhh. Got it! Thank you

 

[Quick & Dirty]

When upgrading to the extreme duty chromo axles w/ tapered bearings do you have to put a tapered race in where the axle seal used to be (to accommodate the different bearing style?)

How do the tapered bearings stay lubed?

Remove the seal. The tapered race goes in the bearing bore, not where the seal was. Gear oil lubes the tapered bearings. Tapered have a seal on the outside of the bearing, so you need an axle with a smooth area for the seal to ride next to the wheel flange.