Axle swap questions

[Gregsenne]

In a weekend or so, I am swapping axles with a guy who has a 57 chevy on a frame from a 77. My truck is an 86 1/2 ton, with a Dana 44 in the front, and a 10 bolt rear. His truck is 3/4 ton, with a Dana 44 8 lug on the front, and a 14 bolt in the rear. His truck has a 6" suspension lift.
I've already looked over the truck, and everything seems like it will work.

I want to get the swap done as quickly as possible, so I want to be prepared and not have to run to the store a million times. Here's my questions:
1. Are the brake lines the same size between 1/2 tons and 3/4 tons? We both have rear drums, front discs.
2. Are the yokes different sizes between the axles? In other words, am I going to have to go buy new pinion seals and crush collars, and swap yokes?
3. Even though he has a 6 inch lift, I think driveshaft length will be fine, as his driveshafts look like the slip part is extended out very far. It has a NP205 so rear driveshaft is yoke-to-yoke, with slip in the middle, instead of the slip in the output shaft of the tcase.
4. Anything else I'm missing? I'm taking his springs too, so I'm just unbolting brake lines and ebrake cables, driveshaft, top shock bolts, and then the bolts holding the leaf springs onto the frame, and sliding it out and sliding the other in.


Also, does anyone know if drum brakes from a 12 bolt rear end will fit a 10 bolt?

Thanks for the help!
Greg

[Firebirdjones]

The yoke on the 14 bolt rear will likely be a 1350 series u-joint. The yoke from your 10 bolt won't fit the 14 bolt so I don't know what you mean about swapping yokes.

The easiest solution for this is to get what I call an "adapter" u-joint with 1350 series on one side and what ever you have for a driveshaft (probably 1330 series) on the other side.

Or you could have a driveshaft made for the truck and use 1350's throughout and then there wouldn't be much worry of breakage,,,costs more money though.

On your other question of rear drum brakes, are you asking if a 12 bolt truck rear brake backing plates bolt to a 10 bolt truck axle housing?

If so,,,,yes the backing plate bolt pattern is the same. However some of the shoe sizes changed throughout the years, so making sure the proper drums are used is something to keep in mind.
I swapped my 72 12 bolt truck rear for a 78 12 bolt truck rear which had 3/4" wider shoes on it.
I also ran into another unexpected issue with the front Dana 44. The 72 dana 44 I pulled out of mine had a smaller axle tube diameter than the 78 dana 44 I installed, (.200" difference) requiring slightly larger U-bolts. Both were 1/2 ton blazers, but I guess GM beefed them up slightly in the later 70's.

You mentioned pulling the springs and all for your swap, so this little setback won't be an issue for you.

[76stepsidechevy]

Might want to have spring eye bolts on hand as they often seize to the sleeve in the spring eye bushings and need to be cut out. Mine were 9/16 and 7/16 and I had to order some as nobody local had any.

[Gregsenne]

Ok thanks. With the different sized yokes, I was hoping I could unbolt the yoke from the one axle, and bolt it on the other. Sounds like this won't work??

As far as brakes, I was only wondering if the brake parts themselves were the same between a 12 and 10 bolt, like all the brake parts besides shoes (like the springs and bars and even the brake cylinder). Reason I was asking is because the 12 bolt I am using for the swap doesn't have brakes, and I'm getting brakes from a 10 bolt. But, I took my brakes off the 10 bolt last night so I'll find out in a minute.

[Firebirdjones]

On the 10/12 bolt brakes......If you are taking the backing plates off, then yes you can interchange the rear brake hardware.

If the rear backing plates are the same size, then chances are you can swap things like your springs, shoes etc...(spring hardware should be the same). Where you run into some differences can be the wheel cylinders, different sizes and bore diameters depending on the year of the truck and brake options. Shoe sizes can also differ depending on the year and brake options, which will also change the size of the drums. These are all just things you'll have to check if you want to miss match parts. However moving the entire backing plate will work along with it's hardware because that bolt pattern didn't change. Not sure if any of that made sense, and I'm not quite sure what parts exactly you want to swap here.....

On the yokes (14 bolt vs 10 bolt). The 14 bolt has a pinion shaft diameter of 1.75 and is 30 spline. On the 8.5" 10 bolt it's pinion diameter is 1.625 and 30 spline. It simply isn't going to bolt onto a 14 bolt.
You'll need an adapter U-joint to mate your driveshaft to the 14 bolt if the truck/driveshaft originally had a 10 bolt behind it.

[Gregsenne]

Ok that makes sense. I'll make sure I have the adapter U joint for when I swap his truck, and I'll probably have my driveshaft redone. Not sure if I'll be able to keep the driveshaft the way it is and put on a 6 inch suspension lift.

What about the yoke on the front Dana 44? Are they the same between 6 lug and 8 lug axles? Or will I have to get the adapter U joint here, too?

Also, any worries about my calipers since I have the 6 lug 44 right now and going to the 8 lug?

Thanks.

[Firebirdjones]

They made 2 different pinion diameters on the Dana 44's. 1.125"/10 spline and a 1.376"/26 spline.

I don't know which applications would have either because these diffs were used in everything from jeeps to dodges, internationals, fords etc....

I'd guess the smaller diameter would have been in the early years of use when it was introduced in 1953 and throughout part of the 60's...

Because of this Dana 44's had 2 different U-joints. A 5-74 considered a closed knuckle used up to about 1969 and a larger 5-260 considered an open knuckle.

With that said I might guess that your yokes and U-joint sizes are probably going to be the same with the newer years you are working on. So I don't forsee an issue here.

I believe the calipers will also be the same size as I don't beleive the rotor diameter changed from 6 to 8 lug. Don't quote me on that, check the rotor to be sure.