M916 and Allison HT4070

[glj]

I have an M916 with the Cat 7155 16 speed. I would love to have the Allison 7 speed 4070 behind the ntc400 engine. Assuming I could acquire a 4070, is it possible to change out the trannys; and approximately (the big things) what modifications would be required? Thanks for any and all help. Gary.

 

[wreckerman893]

I personally prefer the CAT. What do you hope to accomplish by putting an Allison in it? You will not get anymore top end. I drove an M916 with the CAT in it in the Army and 56-58 MPH is about all you are going to get.
I think the CAT pulls a lot better than the Allison.
The downside it that it is hard to find a CAT dealer that can work on them since they had very few civilian applications.

 

[av8or]

Mine would run about 70 mph before the 53" tires, now it will do a it +. I believe the cost of the HD 4070 SP would make it cheaper to trade trucks. I'll look tomorrow to see if there is any thing moved (transfer case, etc.)

 

[wreckerman893]

Mine would run about 70 mph before the 53" tires,

Are you talking about an M915 or an M916? I never saw a M916 that would go over 62 MPH if you pushed it over a cliff in neutral. The M915's with the CAT in them would run 70+.

 

[av8or]

I was referring to my M916 with a Allison push button 7 speed. The M915A1 with 11.00R24 will exceed 70 mph. Both trucks speeds were gps checked. The M915 with Allison HD 4500 I have not verified with gps but will exceed 80 mph on the speedo on 10.00r20, and it is move'n on

 

[av8or]

Transfer case location is the same, drive shaft from transmission to transfer is shorter. Oil cooler in fender well looks easy, but requires rad. hook up.