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Old 09-01-2024, 10:22 AM   #1
LynnB
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Need measurements for C30 dually rear axle

Be glad to share the back story if anyone is interested.

Question: would someone be willing to measure flange to flange on a square body C30 dually rear axle assembly. Need the over all width.

Would also like to know the measurement (center to center) of the leaf spring pads.

Any help is greatly appreciated.
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Old 09-01-2024, 12:33 PM   #2
kwmech
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Re: Need measurements for C30 dually rear axle

There are a few dually rear axles. 14 bolt, dana 70, dana 70hd wide, and I think there is a 14 bolt wide. Then there is the early HO72. So yeah, a back story or a pic
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Old 09-01-2024, 11:49 PM   #3
LynnB
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Re: Need measurements for C30 dually rear axle

Part of the story is here:

https://67-72chevytrucks.com/vboard/...d.php?t=853305

One correction: I noted the wheel bore center incorrectly. Should be 5.84 inches.

The rear gear in my 49 Studebaker dump truck is a 6.66:1 ratio. Even with the tall tires, that poor motor is really screaming when I hit 70.

My granny gear is useless. Unloaded, I always start out in 3rd gear. Even with a load, I start out in 2nd.

Would like to put a 4.10 rear end in it. There are no such gears available for the Studebaker rear.

I would like to keep my cool wheels. Don't want to carry two spares.

I don't think the mounting flange is large enough to redrill for my 5 lug by 8 inch bolt pattern. I already checked to see if the circle was the same on some of the old 10 lugs in the rear, 5 lugs in the front Chevy. They are not.

I just reached out to one of the adapter companies today to see if they can make an adapter to go from a 8 lug Chevy from a square body, to my 5 x8 wheels. If they can, and depending on how much width that adds to the overall flange to flange, I am wanting to see if a square body C30 dually axle will fit. I see there are two, but i don't know the flange to flange width on either.

Flange to flange on my Studebaker is 67 inches.
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Last edited by LynnB; 09-02-2024 at 09:03 AM.
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Old 09-01-2024, 11:51 PM   #4
LynnB
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Re: Need measurements for C30 dually rear axle

One more pic.
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Old 09-02-2024, 09:02 AM   #5
LynnB
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Re: Need measurements for C30 dually rear axle

I guess, ideally, I would like to know the specs on all three dually axles that came in the square body dually. Then, once I get measurements for the adapters, I can see if one of them is close enough for my Studebaker.
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Old 09-02-2024, 09:13 AM   #6
LynnB
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Re: Need measurements for C30 dually rear axle

Found a post on another board that said the Dana 70 was 72 inches flange to flange.
Don't know if that is the standard or the wide. It would be too wide to fit under my truck.

Anyone have flange to flange on the other Dana 70 dually rear?

You can see from this pic, I could stand to go a little bit wider, but not much. I don't want any part of the wheel/tire outside from under the bed.
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Old 09-02-2024, 12:14 PM   #7
kwmech
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Re: Need measurements for C30 dually rear axle

If you can get the adapters for the rims they are large enough to clear the drums on a single wheel 14 bolt- (67'' wide). May have to move the spring perches, but that's not a big deal. Gear availability on a 14 bolt ----3.42, 3.73, 4.10, 4.56, 4.88, 5.13, 5.38 and a 3.21 (if you can find a set)
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Old 09-02-2024, 08:51 PM   #8
LynnB
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Re: Need measurements for C30 dually rear axle

I have a line on a rear axle with 4.10 gears. That would be about perfect for my 350 (bored .040) and five speed trans without OD. That would take me from 5200 rpm at 70 mph down to about 3200!!!

Seller is going to measure flange to flange tomorrow.
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Old 09-03-2024, 09:32 PM   #9
lolife99
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Re: Need measurements for C30 dually rear axle

Quote:
Originally Posted by LynnB View Post
Be glad to share the back story if anyone is interested.

Question: would someone be willing to measure flange to flange on a square body C30 dually rear axle assembly. Need the over all width.

Would also like to know the measurement (center to center) of the leaf spring pads.

Any help is greatly appreciated.
I have this chart saved for future use.
Hope this helps,…
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__________________
Keith

Convert to disc brakes.
http://67-72chevytrucks.com/vboard/s...d.php?t=444823
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Old 09-07-2024, 10:56 PM   #10
LynnB
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Re: Need measurements for C30 dually rear axle

Thanks.
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