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| | | | Joined: Apr 2005 Posts: 5 New Guy | | New Guy Joined: Apr 2005 Posts: 5 | I have a 51 Chevy 1/2 ton with the 4 speed transmission. Is the 4 speed transmission in the 3/4 ton exactly the same as for the 1/2 ton, or what is the difference, and what is needed to make it work? Then is the u-joint the same? | | | | | Joined: Jan 2008 Posts: 4,962 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,962 | 48-54 is the same. In 55 they started using a parking brake on the back of the transmission, but the transmission itself is the same. | | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | As Ken stated, the transmission is the SM420 for both applications. No the U-joint is not the same. The 3/4 ton U-joint is heavier and is about impossible to find. No one is making a replacement for it and about the only way you will find one is if someone has some NOS on the shelf or a good junker.
Joe, if you have a four speed in the 1/2-ton already then why are you asking about the 3/4-ton??? All of the parts to rebuild the SM420 are avalable from Novak and all of the parts for the 1/2-ton U-joint and coupling are avalable from most of the vendors.
Denny Graham
Sandwich, IL
Last edited by Denny Graham; 04/22/2010 12:33 PM.
Denny G
Sandwich, IL
| | | | | Joined: Apr 2005 Posts: 5 New Guy | | New Guy Joined: Apr 2005 Posts: 5 | Know where a 3/4 ton truck is with a good 4 speed transmission and would like to keep a good spare transmission ready to put in my truck. | | |
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