macks and brockways Posted January 11, 2010 Share Posted January 11, 2010 I have wanted to add a auxiliary transmission to a couple of trucks in the past, but have refrained from doing so due to the high cost of the spicer 1241 and its replacement the TTC1750. The reason I want to do this is gain more on road speed/lower cruise rpms. These trucks are geared perfect for the off highway work as they sit so I am not re gearing the differentials, nor am I changing the front transmissions: so he goes my questions. I have considered trying to use a T20xx as an auxilary transmission..they are cheap, tough and have .60 overdrive. I spoke with a friend who is an engineer at Eaton and he said it would not work due to the input shaft not being designed to take the weight of a driveshaft and something else about the front bearing design. Well I spoke with another member of this board and he said he had seen it done...and spoke of using a carrier bearing right at the yoke of the front shaft to alleviate some of those concerns. Have any of you ever seen this done before? Success stories or horror stories? Think the 2050/2060 or 2070 is strong enough? What would you use for the front yoke? Think the carrier bearings rubber mount would move to much? Trans would be mounted to frame and front shaft supported at input to auxiliary by a carrier bearing? I realize the TTC 1750 is rated at 17500FT lbs of input torque to account for the torque multiplication in the front transmissions lower gears....however if you look into one of these they don't appear to be built any "heavier" than the Mack transmission. I will also mention trucks are already 24.5 tall rubber, and as I said before not changing rear ratios or differential ratios. Thanks in advanceGot any cheap Tremec 1750's or Good Spicer 1241's laying around? Quote Link to comment Share on other sites More sharing options...
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