65-79 ring and pinion in a '63 carrier?

[Duke W.]

A buddy is looking at purchasing a complete '70 3.36 Positration axle and putting all the parts in his '63 carrier, including the companion flange, which has a different spline count than the '63 drive flange.

The 65-70 crush sleeve is also different. I think it's the same length but a different ID to be compatible with the geometry of the later drive pinion.

Another issue is whether the '70 axle came from a manual or automatic. The auto uses a different companion flange designed for a larger u-joint. I don't know what trans the doner had.

Has anyone done this? Can a 65-70 ring and pinion be installed in a 63 carrier using a '70 manual trans companion flange and crush sleeve?

Duke

[Gary R.]

Re: 65-79 ring and pinion in a '63 carrier?

Hi Duke,
Yes the 70 posi case and gears will fit the 63 housing. Use the later crush sleeve or better yet use a solid sleeve fit to the correct drag- 18 lb/in.

The 70 will have an Eaton posi probably with the weaker 10-18 spiders and solid clutches. If he wants a stronger unit then polish and tune it with 10-17 spiders, add heat treated ones for more strength.

You're going to need a new pinion yoke if the 70 is from an auto or you can use a conversion U-joint with the large 1330 yoke. You need a 1310 yoke.

You'll find the shims used in the 63 are thinner then the ones in the 70 so you're going to need to locate them in varioius sizes. I grind them to fit on a surface grinder. The 63 caps are not as strong but depending on how the car will be driven and how much power it has they''' probably be ok. I've fit many steel caps to these for those that like to launch the car without blowing up the diff. The 70 housing is actaully a better one then the 63 but it's not correct.

Good luck, check my threads on rebuilding them if you want to tune the posi. I never use the posi springs anymore. Never hammer and the posi works much better.

Gary

[Duke W.]

Re: 65-79 ring and pinion in a '63 carrier?

Thanks for the info. This is for a NCRS restoration and the car will not be driven hard or raced, so if the used '70 internal parts pass visual inspection, Positraction preload, yoke end play specs, they should be up to the task.

Duke

[Wayne M.]

Re: 65-79 ring and pinion in a '63 carrier?

Thanks for the info. This is for a NCRS restoration and the car will not be driven hard or raced, so if the used '70 internal parts pass visual inspection, Positraction preload, yoke end play specs, they should be up to the task....Duke

Duke --- Here's proof it works, as Gary described. An almost brand new posi case and 4.56 gears. Figuring from the stamped gear dates, installed late '66 or later. Car was taken off road in 1968, so really low mileage, which is why it is so clean.

Eaton EDB-30175 (series 4) case with 14-spline pinion gear #3820897 (takes the small '63-4 pinion flange with "823" cast). Installed in original '64 carrier 3818753-N, cast J_18_3, stamped CF_1_3_64 (so owner replaced original 4.56's with same ratio). Also "303" rear cover with fine-thread filler plug.

Have put it in my L78 (temporarily, 'til I get the FA's rebuilt), and it runs perfectly.

[Gary R.]

Re: 65-79 ring and pinion in a '63 carrier?

Waynes picture shows the early bearing caps and 5 line bolts, you can use the caps for stock setups but replace the bolts with socket heads for a little added strength.Bottom tap the holes and countersink the lead in,like you do a short block with the head bolt holes. If you look you'll see how sharp those posi window edges are, which are common areas for cracking toward the cross shaft. Be sure to spray yours good with brake cleaner and blow it off, if you have a crack it will show wet.