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Old 09-11-2016, 09:23 PM   #73 (permalink)
cosmick
Experienced UAW Mechanic
 
Join Date: Sep 2014
Location: Bear Lake
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Quote:
Originally Posted by funkhoss View Post
I did consider what you are suggesting--not the transmission in the Duramax trucks, though, but rather the five speed transmission that came in 3/4 and 1 ton pickups in the 1990's (the NV4500). With an NV4500, I could theoretically have enough ratio spread for towing and economy, and leave the same rear end in the car all the time.

However, there are a few reasons that I ultimately didn't go that route:

-The NV4500 is a fairly expensive transmission, even used, and pretty much never shows up in U-Pull yards around here. It would have cost at least 10 times what I paid for the NV3500. It also weighs twice as much as the NV3500 and would have required more extensive floorboard and crossmember modifications to fit.
-The NV 4500, besides being heavier, also has more parasitic losses and much wider "gaps" between the gears than the NV3500--all of which would make it less efficient.
-And if I went with the NV4500, I'd be running a "light duty," high-geared rear end while towing--and as I discussed earlier, there are many reasons that isn't a good idea.

-Funkhoss
The Camaro T56 was offered in 3 versions, but with some mix and match you can combine the 2.97:1 first with the 0.50:1 sixth, you can combine the 3.36:1 first with the 0.62: sixth.
The ZF S6-650 had a 0.72:1 sixth in the Fords, but GM versions got 0.76:1, and aside from their size and weight, their internal hydraulic pump adds much drag on the engine. The price is even higher than the Camaro T56, so forget it.
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