Narrowing a 68/newer 3/4 ton rear axle, anyone done it?

[buckroseau]

Slowly moving along. Dropped off a few parts at the sandblaster last week. Hoping to pick them up this week.

Also had to slightly relieve the axle tube on each side of where the u bolt sits. The old axle was approx. 3" dia. This new axle is approx. 3.250". With the mounts so far out and the u bolt at such a steep angle it could not fit over the tube and line up correctly. Beveled out each side about a 1/16" to 1/8". I saw on another thread for a c20 they didn't do this. Although on that one the mounts were further in so the angle wasn't so steep. Not sure if this is a pre 62 c20 thing or not.

Matt

[Captainfab]

Did you have to open up the notches in the trailing arm mounts to accommodate the different angle?

[buckroseau]

Originally Posted by Captainfab

Did you have to open up the notches in the trailing arm mounts to accommodate the different angle?

No. The angle is the same as the other axle. The axle tube is just a 1/4" larger. Everything is the same, stock.

[azdeltawye]

Originally Posted by buckroseau

…Also had to slightly relieve the axle tube on each side of where the u bolt sits. The old axle was approx. 3" dia. This new axle is approx. 3.250". With the mounts so far out and the u bolt at such a steep angle it could not fit over the tube and line up correctly. Beveled out each side about a 1/16" to 1/8". I saw on another thread for a c20 they didn't do this…Matt

Thanks for jogging my memory –

Actually I had to do this on my ’65 C20 14-bolt conversion as well. I failed to mention this tidbit in my build thread since I did the writeup several months after completing the job and didn’t have any pics of the notched axle tube to remind me…

As you can see in the pic below the axle tube is larger than the distance between the U-bolt holes. I used a die grinder to remove about 1/8” of material from the tube in these two areas until the U-bold fit over the axle tube.

[buckroseau]

Originally Posted by azdeltawye

Thanks for jogging my memory –

Actually I had to do this on my ’65 C20 14-bolt conversion as well. I failed to mention this tidbit in my build thread since I did the writeup several months after completing the job and didn’t have any pics of the notched axle tube to remind me…

As you can see in the pic below the axle tube is larger than the distance between the U-bolt holes. I used a die grinder to remove about 1/8” of material from the tube in these two areas until the U-bold fit over the axle tube.

Exactly what I did. Little better pic took tonight.

Matt

[buckroseau]

Few pics from tonight. Picked up the swing arms and a few other parts today from the sandblaster. I was hoping to not drill out those stock reinforcement plates, but 1 side had already pulled away on both of them, as you can see in the pics. Drilled out the remaining spot welds in the drill press. LOTS, and lots of rust underneath. I'm gonna drop them off again at the sandblaster tomorrow and have them cleaned up before I weld the new plates on.

Matt

[buckroseau]

Few pics from the last couple days. Finished painting parts and started installing......

[buckroseau]

No brakes yet or driveshaft yet, but put the wheels back on just to see if everything looked ok. And it did. Axle seemed slightly shifted to the right, but it may have been that way before? I have the stock pan hard rod installed, but I ordered up an adjustable one from speedway tonight so I can crank it over about 3/8" of inch and get the wheels centered from side to side.


Quick question: I thought I read somewhere that with this conversion you didn't have to modify the driveshaft. It seems like it needs to be cut down about an inch. Anyone else have to do this?

Matt

[buckroseau]

Figured I would post a few pics since I'm essentially done with the rear axle swap. Installed an adjustable sway bar link so I could move the axle to the left approx. 3/8" to center the wheels in the wheel wells. Also I had to shorten the driveshaft. I shortened it 2", although I think 1.25 to 1.5" would have been better. Although 2" shorter should work fine. I had to take the front driveshaft out as well to have it balanced with the rear. Sorry, didn't take any pics.

Rebuilt the front brakes with new wheel cylinders and pads. Hoping to bleed the brakes in the next few days along with the clutch.

Matt