can i use a 1/2 shaft in a 3/4 axle

[trav0302]

I haven't checked shaftes yet. but after that deal with the burs i would feel safer if i switched the shaft out. plus i knowtist some rust on the shaft in the tube aways up. I have the old dana 44 the came out of the 72 but its a 1/2 ton 72 this axle is a 81 3/4 ton will the shaft work? I would for sure understand if not. My gues would be tubes are different lenghts but i gues it wouldn't hurt asking.

 

[sweetk30]

outer stubs swap from 10 bolt to dana 44 .

but inners wont swap back n forth. diffrent splines .

but early dana 44 had smaller u-joints on them. so upgrading to bigger newer dana 44 shafts is comon to do.

 

[trav0302]

both axles are dana 44 if that matters

 

[sweetk30]

swap away then.

like i said swap both as to bigger u-joints.

 

[trav0302]

awsome thanks bro! I'll feel way better getting that other one out of there.

 

[kennyw]

There is no difference between 1/2 and 3/4 ton axleshafts of the same vintage/axle type. However, the axle is not a D44 if it is original to an '81 (that doesn't mean it wasn't swapped along the way). I would also not put the smaller 71/72 axleshafts in a newer axle.

 

[trav0302]

The 81 is a dana 44 i picked up for my blazer. My 72 came with the oem dana 44. I'm wanting to put the axle shaft from the old 72 axle in the new swapped in 81 axle. I hope i'm making that sound right. It kinda hard to explain.

 

[kennyw]

The 81 is a dana 44 i picked up for my blazer. My 72 came with the oem dana 44. I'm wanting to put the axle shaft from the old 72 axle in the new swapped in 81 axle. I hope i'm making that sound right. It kinda hard to explain.

That is a good enough explanation. I would advise against that. '71-72 D44's used a smaller axle u-joint and are weaker than the stock '73 up D44's.

 

[trav0302]

can't you up grade the joints or is it not worth it?

 

[kennyw]

can't you up grade the joints or is it not worth it?

No, you would need to change the yoke built into the shaft to upgrade to the larger joint.

 

[imiceman44]

The 81 is a dana 44 i picked up for my blazer. My 72 came with the oem dana 44. I'm wanting to put the axle shaft from the old 72 axle in the new swapped in 81 axle. I hope i'm making that sound right. It kinda hard to explain.

I seriously doubt it is a D44 if it's an 81.
Or that it's an 81 if it's a D44.
But as you now know, the earlier axles have smaller Ujoints as well as thinner outers which means the spindle will be too big for the shaft and the shaft will wobble and ruin the locking hubs and the joints are weaker.
However 73 wasn't the break, I believe it was 76.
I have axles from 76 all the way down to 71 and all have the smaller shafts except a couple of the 76 axles.

 

[kennyw]

I seriously doubt it is a D44 if it's an 81.
Or that it's an 81 if it's a D44.
But as you now know, the earlier axles have smaller Ujoints as well as thinner outers which means the spindle will be too big for the shaft and the shaft will wobble and ruin the locking hubs and the joints are weaker.
However 73 wasn't the break, I believe it was 76.
I have axles from 76 all the way down to 71 and all have the smaller shafts except a couple of the 76 axles.

The Ujoint break was '73, the outer change was '76/77.

 

[trav0302]

ok then i guess thats a no go for sure. But now why would you say my 81 isn't a 44 # match and the year says 81 on it

 

[K85 Octane]

make sure to get the flat top knuckles off that '72

 

[6.2Blazer]

ok then i guess thats a no go for sure. But now why would you say my 81 isn't a 44 # match and the year says 81 on it

It would be very unusual to see a factory installed D44 front in an '81 considering GM started using the 10-bolt back in the late-70's. When I was growing up every farmer around me had a late-70's 4x4 K20, and some are still in use, and every one I have looked at had a 10-bolt.

 

[trav0302]

Here's a few pics from a few years back when i brought it home with the 14 bolt.

 

[6.2Blazer]

I think it looks like a D44 but none of the pictures you posted are that great for identifying one. Get a straight on shot of the diff cover.

Were the axles already out of the truck and the seller said they were '81 model year, or were they will under the truck? Considering that even a few years ago an '81 would be 25+ years it wouldn't be unusual to not be the original axle.

Don't get me wrong as if you have a D44 than great as my comments are just to verify you know what you actually have and the parts will interchange. I've just seen a lot of mis-information on whether these axles are 10-bolts or D44's over the years.

 

[trav0302]

it was already pulled when i got it. I was looking for a pic with the cover. Still looking

 

[trav0302]

here ya go. had to find my old cover. I didn't know 10 bolt had a 8 lug.

 

[kennyw]

This is a Dana 44 vs 10 bolt

Your axle looks like a Dana 44 to me.

The 10 bolt is more round compared to the Dana 44. The 10 bolt front was used exclusively in 1/2 and 3/4 ton axles by 1981/82. But, it is so easy to swap them around that it was not unusual for people to swap in the older D44's if they wanted to.