Medium duty engine/tranny?

If it is used in a Class 4 to 7 vehicle, it is medium duty. Too many people throw that term around loosely.

My Freightliner Business class M2 is a medium duty. It weighs 5.75 tons. Perhaps weight has something to do with it. The transmission looks bigger than my old 7.3PSD engine. All pickups, no matter how bad-ass they look, are light duty.

I don't know the hows or whys, that's just how they are designated. I'm sure google knows.

I believe the RAM 6.7 is, I know the 5.9 was. Check at the TDR web site.

The Allison in the GM, the 6R140 in the Ford, and the Aisin in the Ram can all be had in medium duty vehicles. The only exception is the 68RFE, but this is mainly due to it not having a PTO provision like the others. People just like to throw the "medium duty" slang around because it makes them feel better about themselves.

Medium duty trucks are those with GVWRs from 14001 to 26,000 pounds.

Some of these guys that brag about having a medium duty engine and transmission, don't even want to recognize that the other two LD truck makers having been providing MD truck power plants longer than them.

It's awarded to most trucks with a Ram logo and very few others! Lol

Bedlam wrote:
Some of these guys that brag about having a medium duty engine and transmission, don't even want to recognize that the other two LD truck makers having been providing MD truck power plants longer than them.

That's only cause ford owns cummings........

To be a bit more specific, some also has to do with how long a motor will last before a complete rebuild. IE 400-600K miles vs 200K. BUT, still that is suspect in my mind, as Navistar had V8 diesel motors with equal mileage before rebuild as GM/Ford had the BB gas rigs back in the 90s, all had a 100K mile useage's. IE the IDI6.9/7.3 motors Navistar in mdt rigs, and Ford used in pickups and the SD350, before the current 450 chassis came out. My idi7.3 has 20 years and 140K, its on its last legs, but still usable. If one wanted a higher miles before rebuild, one went with a DT360/466/530 which had 400K lifetime expectancy if used city driving, 600K if more on the freeway. The T444E and subsequent 6.0, 6.4 V8's had 400K mile useages as the B5.9 and DT360 had. But lighter in weight, approx same hp for like useage.

But, I would agree with bedlam and some others, that it is not used as it should be per say by some forum members.

Marty

Cummins in Columbus, IN builds the 6.7 for RAM and Freightliner on the same assembly line. The only real difference is the adapter that mounts to the back of the engine that the trans will mount to. Oh and the Freightliner engines are painted red.

The Aisin is used by other manufactures in Medium Duty applications.

Ford uses their trans in the 650/750's now. The Allison they used to use was NOT the same trans as in the GM trucks. The 6.7 Cummins they used to use was the same as the RAM Cummins.

Someone can correct me but I have a fiend with a Kodiak and he says his Allison is different then the ones offered in the pickups. Other Allison applications like motorhomes can be different also.