Swapping axle parts question

[Johnl48]

I talked to a truck parts Company regarding what I needed to convert my current front axle dana 44 from drum to disc brakes. He said new knuckles, new spindles and new outer axle shafts. (Inner shafts will work) cost $1,600.00
I recently found this near me so my question is can I pull those parts from this and put them on my Axle ? I replaced seals, sandblasted and painted my axle and it is bolted up to the frame already so I don't want to swap ii if I don't have to

My truck
1970 k20 4x4 3/4 ton 8 lug. Has a 10 bolt dana 44 with 4.09 gears

[Bigdav160]

I think the whole thing will bolt in.

No idea about part swapping

[Johnl48]

He just messaged me it is a GM 10 bolt. I suspect parts are not interchangeable ?

[kwmech]

The knuckles out are interchangeable....BUT your 1970 inner shafts will not. The '70 axle shafts used the 260 u joint and the 10 bolts used the 289 joint (now a 760) Just use the complete 10 bolt, they are just as strong as the 44 if it has the 30 spline inner shafts---even with the 28s they are comparable. Just make sure you match the gear ratio. Inner 10 bolt shafts will not inter change with 44 shafts

[Johnl48]

Originally Posted by kwmech

The knuckles out are interchangeable....BUT your 1970 inner shafts will not. The '70 axle shafts used the 260 u joint and the 10 bolts used the 289 joint (now a 760) Just use the complete 10 bolt, they are just as strong as the 44 if it has the 30 spline inner shafts---even with the 28s they are comparable. Just make sure you match the gear ratio

So the outer axle shafts on the gm won't fit on the dana inner shafts ?

[kwmech]

No--the u joints are different sizes, double check though, but I doubt GM changed the shafts just for the 3/4 ton. You can post up a close up pic of the joint and I/we may be able to confirm

[Johnl48]

Originally Posted by kwmech

No--the u joints are different sizes, double check though, but I doubt GM changed the shafts just for the 3/4 ton. You can post up a close up pic of the joint and I/we may be able to confirm

Ok ill do that tomorrow thanks

[Johnl48]

Originally Posted by kwmech

No--the u joints are different sizes, double check though, but I doubt GM changed the shafts just for the 3/4 ton. You can post up a close up pic of the joint and I/we may be able to confirm

I have to ask at the risk of being called a dope lol. Will all the parts, including gears and axles from the GM fit in the dana housing ? Only reason I ask is I'm far along with the dana already. Just doing this for the disc breaks

[kwmech]

Gears are different, inner shafts are different with seal offset and such. If you can source some inner 44 axle shafts you could go that way. They are available brand new from various suppliers

[Johnl48]

Originally Posted by kwmech

Gears are different, inner shafts are different with seal offset and such. If you can source some inner 44 axle shafts you could go that way. They are available brand new from various suppliers

How would the new inner shafts differ from the ones I have now in my dana 44 ?

[kwmech]

U-joint size, the small u-joint shafts are no longer being made. So if you had a joint break and wipe out one of the ends you'd be upgrading anyways with 2 pieces. Seeing as you have the outers, just buy some inners

[Johnl48]

Originally Posted by kwmech

U-joint size, the small u-joint shafts are no longer being made. So if you had a joint break and wipe out one of the ends you'd be upgrading anyways with 2 pieces. Seeing as you have the outers, just buy some inners

Ok thanks

[Johnl48]

So my current shaft have the smaller u joint so I will just order the new inner shafts with the bigger joint

[kwmech]

Originally Posted by Johnl48

So my current shaft have the smaller u joint so I will just order the new inner shafts with the bigger joint

there ya go...

[Mike C]

With 4.10 gears, just swap the whole axle into your truck and be done with it. The 28 spline inners are not as strong as the Dana 44 but it has the heavier duty axle joints. In the end, it’s a push.

[kwmech]

He is adamant about keeping the 44 since it is already cleaned up, painted and reinstalled

[Mike C]

If that is the case the spindles on out swap right on. Their is a little difference to the axle thrust bushings on an earlier 44 and the 10 bolt.

I’d still just clean up the 10 bolt and use it. Most cost effective route even if the 44 has been dolled up.

[Johnl48]

So I got the gm axle today, I see the outer axle shaft is about 1/8" longer, the spindles are very slightly different but the knuckles look exactly the same and the spindle fits on both. The disc brake knuckle is on the right..not sure what I'm missing

[Mike C]

IME, the spindles out are interchangeable and you can bolt the 10 bolt brakes on your 44. The drum brake outers may be different as I have no experience with them. I swapped 10 bolt spindles, backing plates, hubs and brakes from an ‘86 K2500 Suburban onto my Dana 44. But the outer thrust bearing setup is different on the two.

I also found that not all of the 10 bolts would accept manual hubs. The snap ring location is different between the auto and manual which surprised me. One axle (‘86) had two grooves, one that fit each type of hub. The other (‘84) had only one groove that fit auto hub but not manual.

[Johnl48]

Original dana 44 hub on left
GM 10 bolt hub on right

[Johnl48]

Drum hub on rt definitely does not have lip for rotor so they do not look interchangeable

[kwmech]

Swap the knuckles unless you want to drill 6 more holes in each backing plate to get the calipers to fit correctly on the knuckle. Look at the bolt pattern. the disc brake knuckle has the bolt pattern starting at 12 o'clock. The drum pattern starts at 11. Hubs are different, drums slide on from the front. Disc presses on from the back. Why is this getting so complicated? Are you wanting to run the original bolt on locking hubs? The later spline drives are actually stronger instead of relying on 6- 5'' bolts to turn the tire. Also the spindles are not 'identical'. The backside of them are machined a little bit differently for the early and late dust seals. Early had a brass thrust that set down into a differently machined groove. Later models used a plastic/urethane thrust with a V seal to keep out debris. Use all the 10 bolt stuff knuckle out, get new inner shafts with the larger u-joint--------sell all the drum to somebody that needs it and wants to keep period correct for their restoration

[Johnl48]

Originally Posted by kwmech

Swap the knuckles unless you want to drill 6 more holes in each backing plate to get the calipers to fit correctly on the knuckle. Look at the bolt pattern. the disc brake knuckle has the bolt pattern starting at 12 o'clock. The drum pattern starts at 11. Hubs are different, drums slide on from the front. Disc presses on from the back. Why is this getting so complicated? Are you wanting to run the original bolt on locking hubs? The later spline drives are actually stronger instead of relying on 6- 5'' bolts to turn the tire.

Not trying to be complicated. I was told by the parts guy I can use original hubs guess he was wrong. I can figure it out from here

[kwmech]

Just trying to help you out here to get you the correct info. I do this stuff everyday and own a 4wd shop

[57taskforce]

Originally Posted by kwmech

Swap the knuckles unless you want to drill 6 more holes in each backing plate to get the calipers to fit correctly on the knuckle. Look at the bolt pattern. the disc brake knuckle has the bolt pattern starting at 12 o'clock. The drum pattern starts at 11. Hubs are different, drums slide on from the front. Disc presses on from the back. Why is this getting so complicated? Are you wanting to run the original bolt on locking hubs? The later spline drives are actually stronger instead of relying on 6- 5'' bolts to turn the tire. Also the spindles are not 'identical'. The backside of them are machined a little bit differently for the early and late dust seals. Early had a brass thrust that set down into a differently machined groove. Later models used a plastic/urethane thrust with a V seal to keep out debris. Use all the 10 bolt stuff knuckle out, get new inner shafts with the larger u-joint--------sell all the drum to somebody that needs it and wants to keep period correct for their restoration

This is all great accurate info that doesn’t seem to be all that well known on the Internet. That ‘70 axle is a bit of a hodgepodge on GM’s (dana’s) part. Ive seen this swap done with the later 44/10 bolt outer parts as has been outlined here. I would have swapped a whole matching ratio disk brakes axle in it but I certainly understand and appreciate why you chose not too. Get the correct inner axles and let her eat!