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| | | | Joined: May 2006 Posts: 237 Shop Shark | | Shop Shark Joined: May 2006 Posts: 237 | I know this is not the correct year truck to be discussing on the bolt, but hope someone would know.
Truck has a 4 speed transmission in it. I'm fairly sure the SM420 was replaced with the SM465 by this time. Did Chevy make any other 4 speeds they would have put in this truck? Do you think it's a SM465?
Thanks! | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy jhaa_lives, according to my books, truck series CE65003, and CE65013 with 366,379,427,and 432 engines left the factory with the SM465 as their standard [not optional] transmission, hope that helps. | | | | | Joined: Sep 2006 Posts: 1,276 Shop Shark | | Shop Shark Joined: Sep 2006 Posts: 1,276 | More common in Ford and Dodge the New Process 435 was used in some Chevy’s 70 to 76 if it has a cast iron case and an aluminum top cover with the PTO port on the passenger side it is likely a NP435. This is a very tuff transmission however if you plan to use it 4th gear is not 1 to 1 it is 1.74 to 1 so you will want a little taller gears in the rear.
Hope this helps | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | The transmission I took out of the 78
GMC 6500 I had is a Spicer 5 speed direct drive 5th.
It's for sale if anyone is interested, only has about 84,000 miles on it. $75, if you pick it up, PTO included.
Grigg | | | | | Joined: Mar 2005 Posts: 1,029 Member | | Member Joined: Mar 2005 Posts: 1,029 | Grant, from what I have read, top gear on the NP435 was 1:1; third was 1.79:1. It would not make any sense not to use 1:1 for at least one of the gears on a transmission, as it is basically free. | | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | I too have never heard of an automotive transmission that does not have a 1:1 ratio somewhere in it.
1.74:1 in high gear sounds fishy...
Grigg | | | | | Joined: Sep 2006 Posts: 1,276 Shop Shark | | Shop Shark Joined: Sep 2006 Posts: 1,276 | My info states that it is different from most because of this and gives the Ratios as 1st 6.68:1, 2nd 3.34:1, 3rd 1.66:1 and 4th 1.74:1 and looking at it now that would make 4th lower than 3rd so this is screwy. Time to write Four Wheeler and tell them they printed some bogus info. | | | | | Joined: Sep 2006 Posts: 1,276 Shop Shark | | Shop Shark Joined: Sep 2006 Posts: 1,276 | Grigg wish that Spicer you have was an O/D I have yet to find one. | | |
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