0.65:1 transfer case?

[290smallcam]

Looking for a transfer case to replace the stock M813 one. Cant find any HD ones out there on google that have a high gear of in the range of .70:1 to.65:1 ratio? the Oshkosh 5500 has .90:1 ish ratio and is way to big! The M900's are .73:1, looking for a litter lower. Any suggestions.

 

[simp5782]

Looking for a transfer case to replace the stock M813 one. Cant find any HD ones out there on google that have a high gear of in the range of .70:1 to.65:1 ratio? the Oshkosh 5500 has .90:1 ish ratio and is way to big! The M900's are .73:1, looking for a litter lower. Any suggestions.

Oshkosh units
55000 is .98
18000 is 1:1
30000 is 1.36

There isn't anything more overdrive than the T1138 I have ever found that is .73

there are not Any auxiliary cases numerically lower than .70.

You would have to go into a transmission to get more speed with a more overdrive ratio.

RTOOs are .83 .73 .62 OD. Spicer proshifts are .83 and .70
ALLISON 3000 and 4000 series are respectively the same. 4000 series are not available in SAE 2s however.

 

[290smallcam]

did the math, running XZL 12:00R20 and HT740 RPM's are a little high. and that's with the m900 series T case. Thought there would be something out there>

 

[simp5782]

So you are using a small cam or big cam with a SAE 1 housing to an HT740 in an 809 series that you have to raise the cab and front cap almost 7 inches to use? HT740s cost much more than a HT754 and have one less gear, almost mostly only come with Detroit ring drives.

Most vocational trucks use a manual transmission with an OD over an OD transfer case and they used single speed units for simplicity and they wouldnt want to go over 60.

You would be smarter and cheaper over buying an HT740/754 and a transfer case to buy a old dump truck with RWD Allison 3000 world series transmission that has everything you need for the swap. With preferred an 8.3 in it. You would just slide the Tcase back for the 3000 and have a Double OD. Over raising the cab and cap and having to move the case anyway


Or swap the 3rd members for some crash truck 5ton ratios. They are In the 5.63 range

 

[frank8003]

Ford Raptor is still good. How fast You wanna go?

Ford F-150 Raptor Top Speed Limiter Stops Play At 107 MPH | Carscoops

Without the electronic nanny, the 450 HP super truck can hit 134 mph, but Ford decided to cut it short, probably for safety reasons

www.carscoops.com

 

[290smallcam]

Wow 7 inches!!! That's alot. These are Future plans nothing in stone yet. The HT doesn't seem much bigger than the MT Series? Couldn't I just cut the floor out and weld up a tunnel, instead of lifting it 7 inches? Or would I fe better off buying a M931A1. Would the HT fit it better than my M813?

 

[simp5782]

Wow 7 inches!!! That's alot. These are Future plans nothing in stone yet. The HT doesn't seem much bigger than the MT Series? Couldn't I just cut the floor out and weld up a tunnel, instead of lifting it 7 inches? Or would I fe better off buying a M931A1. Would the HT fit it better than my M813?

The mounts for an SAE1 are above the frame unlike SAE2 that are mid frame.

HT740 is 5 inches taller than the MT654.

This is what it takes to so SAE1 mounts in a m939 series.

Simp's Cat 7155 Swap into a M923A1

Ok, so most people complain about how gutless the NHC250 is even with a turbo. Even with 5 speed or Allison they still just have that gap between 3-4 and 4-5 and then there is the top speed in question based on what tires you have. Bigger tires may help you go faster but you do loose that low...

www.steelsoldiers.com