65 Corvair's Steel Front Diff Build

[Ramstrez]

Following this for sure

Thanks for all your work so far

 

[65Corvair]

My parts were machined.
On the left will be used on the driver's side, the right will be for the passenger's side to fit in the axle tube.

You must be registered for see images attach

Now that I have the parts in hand, I can do the finish work on the housing to get the distance between the machined part and the differential carrier bearing correct.

You must be registered for see images attach

 

[65Corvair]

Here are the prints for bearing/seal collars.
Overall, the collars work pretty good, the driver's side OD is a few thousand's too small, so it ended up being a clearance fit instead of a press fit when installing into the main diff housing.
The bearing and seal sizes work well, I was able to install both with the "right" amount of force.

You must be registered for see images attach

You must be registered for see images attach

 

[65Corvair]

I cut off another 3/8 of an inch of the driver's side housing, and it is now flush with the main body of the differential.
Given that it was a clearance fit, I did not want to waste the parts I had. I drilled and tapped some 1/4-20 holes that went partially into the collar. Installing some set screws should be enough to hold the collar in place. I would have preferred to have a press fit, but the collar doesn't see too much load, so I doubt it would be an issue. I sealed the collar to the housing with a bead of RTV. The driver's side is now complete.

https://www.permatex.com/products/g...ltra-black-rtv-silicone-gasket-maker-3-35-oz/

You must be registered for see images attach

You must be registered for see images attach

Next is to tackle the passenger side collar install.

 

[KJowner]

You could get it knurled to bring the size up.

 

[turblediesel]

You could get it knurled to bring the size up.

Or ping it evenly with a center punch.

 

[65Corvair]

Or ping it evenly with a center punch.

I tired the center punch method, it was too undersized for that method to work.

 

[65Corvair]

The passenger side collar is installed.
It was too much press fit for the 1/2 inch treaded rod, so I cut a slit in the tube and welded back together after it was pressed in.
The other cuts on the tube are superficial and happened when I cut off the Center Axle Disconnect from the axle.

You must be registered for see images attach

 

[65Corvair]

I designed up the passenger side mount, and will let sendcutsend.com work its magic and mail me my parts.
All the plates for the passenger side mount are 1/4 inch steel.

You must be registered for see images attach

 

[slowcrawlerZJ]

Thats some awesome ingenuity and fabrication.

 

[65Corvair]

My parts arrived and I was able to do a fitup. With my sendcutsend order, I also had some aluminum plates made to act a fixture for welding.
The normal aluminum diff has the passenger side mount perpendicular to the front mounting surface. I tacked up passenger mount at 90 degrees, but it gets pretty close to the starter. (Since I used a high pinion D30 instead of low pinion)
I will cut the welds and clock the diff housing down 3 or 5 degrees and see if that helps get more clearance to the starter.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[u2slow]

You're in a prime spot to drop/shim the cradle down some. Even just a little could help. I've gone to 3/4".

 

[u2slow]

Actually, nevermind.... the diff and engine both are bolted to the cradle

 

[65Corvair]

Actually, nevermind.... the diff and engine both are bolted to the cradle

Yes, and I also have skid plates that go from the front cradle to the transmission crossmember that I don't want to create a spacer for.

 

[65Corvair]

I did end up rotating the passenger side mount 4 degrees to lower the pinion, however it was too low and caused the diff housing to contact the skid plates. Cutting and rewelding to 2 degrees seems to be just right. It gets it away from the starter some and leaves room for skid plate clearance. Using cardboard as a coarse flexible feeler gauge, I can slide 2 sheets between the diff and skid plate, so just a little less than 1/4 inch.

 

[65Corvair]

A bit of bad news, using a high pinion will not work (At least for an automatic 42RLE transmission) I installed the driveshaft last week, and it gets too close to the transmission cooler lines for my liking. The high pinion may work for a manual transmission, but I do not have a Liberty with a manual transmission to verify.

You must be registered for see images attach

However, I was able to find a low pinion dana 30 locally, and I began chopping.

You must be registered for see images attach

Comparison of pinion location, high pinion on top, low pinion on bottom.

You must be registered for see images attach

A majority of the excess weight has been removed.
The dana 30 front plate and passenger side mount are a direct fit from the high pinion to low pinion.

You must be registered for see images attach

 

[u2slow]

Thats a bummer. I had hoped the hi-pinion could have been used to reduce the half shaft angles. That would take some serious cradle mods I guess.

I recall JBA doing the steel front diff, and settling on the low pinion because of hi-pinion fitment issues.

I briefly looked at using the 8.25", but it seems to be too wide a casting.

 

[KJowner]

If you replace the bent pipes on those lines with 90° fittings you will gain a lot of space.

 

[Ramstrez]

Any updates on your progress yet

 

[65Corvair]

I just got the low pinion mounted in tonight, the position is nearly identical to the original aluminum housing. Using 5012444AA Pinion Flange, the front driveshaft fits perfect.
Next step is to measure up for the driver's side mount and get it designed.