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| | | | Joined: Dec 2011 Posts: 40 Wrench Fetcher | | Wrench Fetcher Joined: Dec 2011 Posts: 40 | I am in the process of swapping out my 4.57 gear set for a 4.10 one in my HO72 Eaton 1 ton axle, in my 46 3/4 ton Chevy pickup...as part of the swap, I would like to convert to a one piece or two piece open drive shaft...
My question is...what problems will I encounter in doing this, or do I have to keep the torque Tube while using my old "original" Granny 4 speed? I really don’t want to keep the torque tube if possible.
| | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | It is not as easy to convert the early nonsynchro transmissions as the SM420.
It would require a main shaft, yoke, and extension housing from a 1 1/2 or 2 ton.
Might be easiest to keep the inclosed front shaft.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Dec 2004 Posts: 1,897 Shop Shark | | Shop Shark Joined: Dec 2004 Posts: 1,897 | 1941-1954 3/4 ton trucks used a hybrid driveline... torquetube to carrier bearing then convetional driveshaft to the rear. No need to change that with a gear swap. However if swapping transmissions, the one piece driveshaft may be easier to fabricate.
Of course a transmission swap has it's own challenges on a 46. The transmission to bellhousing bolting pattern is different than the later chevy and gmc trucks. Most transmission swaps will involve using a modified 1948-1954 bellhousing. An adapter plate could also be used between the old bellhousing and a newer transmission.
I have plans of swapping out the non-syncro crash box in my 1940 gmc project to a fully syncroed nv4500 5 speed. | | |
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