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Allison Question

2773 Views 5 Replies 5 Participants Last post by  Diesel Nut
I am planning a transmission swap in my 1998 H1. The donor transmission is going to be an Allison.
I was wondering from anyone who has experience towing how is the 6 speed compared to the 5 speed?

Right now I am having a hard time finding a 6 speed, but I have found some 5 speeds for $900 to $1000. I know if I can find a used 6 speed it would be at least double.

Would that extra overdrive on the 6 speed benifit my truck?
Would the extra money that I would pay be worth it?

My hummer is over 10,000 lbs and has very poor aerodynamics. But I guess anyone towing a large 5th wheel is also heavy with limited aerodynamics.
Thanks for any help,
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You should have a 4.92:1 total axle gears when you factor in the 1.92:1 geared hub. Portal axles rock.

With that kind of gearing, and knowing how the military Hummers ran, the extra OD will do you alot of good. Persoanally, if you are going to spend the money on a conversion like this, why not get a new unit from a reputable builder like Suncoast and be done with it, no worries, no questions, you know its good.

Also, with a 5 speed, you can upgrade it to a 6 speed with a kit available from Suncoast that includes a new VB and new TCM.
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