Rear axle - early vs late?

From VC-1 to WC64-KD.
dougieboy1
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Rear axle - early vs late?

Post by dougieboy1 »

I have 2 sets of axles for my WC. Both need overhauling.

On one set of axles, the differential cover is bolted on, the other set the differential cover is pressed [?} on to the axle tube.

Is one early and one late?

In the parts manual, there are 2 covers listed, and the layout of the manual suggests one comes with nuts and the other not...... The one without nuts supercedes the other which suggests that the bolted cover axle version came first.

From a bit of googling, the only photo i could find of a VC axle seems to have a bolted on cover so i am again assuming that bolt = early, pressed = late?

Is this correct?

Thanks
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Gordon_M
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Re: Rear axle - early vs late?

Post by Gordon_M »

Happy New Year Dougie.

It's complicated. Absolutely the best information on this is the John Zentmeyer publication which had a TM number and Power Train in the title, don't remember exactly.

VC axles had pressed covers, but they kept breaking them, so they were substituted by later, bolted ones.

As I remember early WC were pressed, but later ones were bolted. It is more complex than that as at some point in production they revised the power train, doubtless with breakage feedback from users, and they beefed it slightly for the WC 6x6 which would be even harder on components. Differential actually got slightly larger, casing different internally to clear, bolted cover, even slightly different axle lengths by just 1/32" or so I vaguely recall. U-Joints and driveshafts beefed too. The result was pretty much everything would interchange but you did need to know what you had.

If you have an early truck, use the pressed cover, if it is a later one use the bolted cover.
Gordon, in Scotland

( Now officially given up on any form of politics )
dougieboy1
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Re: Rear axle - early vs late?

Post by dougieboy1 »

thanks gordon - will use the pressed cover versions
Kaegi
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Re: Rear axle - early vs late?

Post by Kaegi »

3/4 ton trucks started with 8 3/4" differentials with bolted on covers. The, they upgraded to the 9 5/8' differentials and still had bolted on covers in early production. That cover is deeper than the early cover. Then they switch to a welded on cover sometimes in 43. all the welded on 3/4 ton covers are 9 5/8" differentials. Go with those. so much stronger than the 8 3/4.
So your bolted on cover axles could still be 9 5/8 diffs. the easy ways to tell are the mounting stud size. the 9 5/8" diff uses 7/16" studs and the 8 3/4" diffs use 3/8" studs. The 9 5/8 diff itself is substantially larger than the 8 3/4 also
Loffy770
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Re: Rear axle - early vs late?

Post by Loffy770 »

Also the the bolted 9 5/8 axles has a welded plate that says to use 3 gaskets.
On top of the nose on the bigger diff you also have a lock screw for the bearing racer, its easy to spot as it sticks up.