64 axle - 17 spline to 30

[chris1044]

There are a few threads about this already, but none answer the specific questions below. One of my axle bearings went bad and ate into my 17 spline shaft. I was able to score some 30 spline shafts out of a later truck - 6 lug which is what I want to run.

- My 17 lug shafts have a backplate on them, but it doesn't appear to be pressed on. Rather it looks like the wheel studs hold it in place. The new 30 spline shafts don't have this...problem if the backplate is eliminated?

- Can I simply source 30 spline spider gears (or a posi out of a later truck), and swap them in to make the 30 spline axles work with my housing?

The axle measurements are identical otherwise...fully aware of what needs to be done with the axle if I swap the carrier out as I've built a few axles over the years, but I keep coming across conflicting details on this axle swap.


Thanks,
Chris

[The Rocknrod]

Some people know these things better than I, however if we knew what year it was it could make a difference.
I have a 64 C10, had the original truck 12 bolt. I went to quick performance and purchased everything I needed to make it a 30 spline, posi etc.

[chris1044]

Originally Posted by The Rocknrod

Some people know these things better than I, however if we knew what year it was it could make a difference.
I have a 64 C10, had the original truck 12 bolt. I went to quick performance and purchased everything I needed to make it a 30 spline, posi etc.

Like the title says, the year is 1964...my question is exactly what is needed for the 30 spline, and if it's just shafts and spider gears can you delete the back-plates from the axles.

I'm hoping to just be able to get spider gears for a 65+ truck and assemble.

[The Rocknrod]

Hmmmm, I went through this exact thought process when I started mine. Summit was selling the axles and spider gears for the rear axle housing. The backing plates do come off. I removed mine and will be installing rear disc. I'd have to search again for the spider gears and axle set but they are available.

[The Rocknrod]

https://www.summitracing.com/parts/c...del/c10-pickup
and
https://www.summitracing.com/search?...Spider%20Gears

[The Rocknrod]

Here is a pic of mine assembled:
http://67-72chevytrucks.com/vboard/s...7&postcount=36

[The Rocknrod]

Also http://67-72chevytrucks.com/vboard/s...1&postcount=25

[chris1044]

Originally Posted by The Rocknrod

https://www.summitracing.com/search?...Spider%20Gears

Thanks for posting this. Fairly sure this is confirming that all you need to do is put new spiders in and they'll work. For that price though, I'll find a used posi unit out of a 30 spline axle since mine's just an open diff.

I plan to keep discs for now, but I really don't see any function of that backing plate other than keeping dust from getting to the bearing seal.

[pheengurs]

Originally Posted by The Rocknrod

Also http://67-72chevytrucks.com/vboard/s...1&postcount=25

{as per Captain Fab}
The '65 to early '70 12 bolts are exactly the same, as in a direct swap. The '63-'64 12 bolt will bolt up except they are setup for the long panhard bar. The long panhard bar can work with a slight bend in the frame end.

If you are just talking about the internal parts, all truck 12 bolt parts from '63-'82 will interchange. The one thing that is different is in the '63 and '64 12 bolts, they used 17 spline axles and spider gears. '64 and up used 30 spline.

The auto trans trucks could have 3.73's, 3.42's or 3.07's. Some of the later models came with 2.73's.
--------------------------------
nice find Rocknrod!


I'm dropping a 383 stroker into my Mudhoney, and am worried about the ability of the drivetrain to handle the torque...

and this tidbit of information: "all truck 12 bolt parts from '63-'82 will interchange"

is pure gold!