Transmission and transfer options for 818 (809 series.)

[ke5eua]

So after taking to someone today I got to thinking about the options of a drop in solution for my 818. The talk of upgrading to a 931 was brought up but I figured if I were to get rid of the 818 it would have to be for a 1088. A 915/916 wouldn't work for me as the pin size is 3" and using an adapter for 2" kingpins are not dot approved.

So here is the planning stage of this. I have to much time invested in my 818 so what automatic options do I have with minimal modifications needed. I am a fan of the push button Allison that is found on the fmtv series, but I don't believe that will mate to my nhc250 without heavy modifications.
The goal here is to remove and replace without having to refabricate. I don't mind sticking with my current transfer if that makes it easier.

 

[fuzzytoaster]

M915 has a 2" kingpin that accepts 2.5" kingpin so it still works.


Edit: corrected w/ source.

The M915's all have fifth wheels that accept 2-1/2" kingpins.

The M916 and M920 have fifth wheels that accept 3-1/2" kingpins.

The M915 will pull most non-mil trailers w/ ease. The fifth wheel position and height is very good for non-mil trailers.

The M915A1 is extremely easy to drive.

Andy

 

[ke5eua]

M915 has a 2.5" kingpin so it still works.

Sorry, 2 1/2, but still can't use the adapter to use a 2" pin. You keep trying to convince me to get a 915 but I want that 6x6.

 

[Castle Bravo]

Sorry, 2 1/2, but still can't use the adapter to use a 2" pin. You keep trying to convince me to get a 915 but I want that 6x6.

He means 2", I think.

 

[73m819]

915 HAS 2" king pin

 

[Monkeyboyarmy]

Once you go 915, you don't go back.

 

[ke5eua]

Well that changes things then.

 

[ke5eua]

What about 5th wheel distance from rear, any issues with military trailers. I know Brett ran into a rubbing issue with a civi box trailer.

 

[Monkeyboyarmy]

What are your intentions with the 818?

 

[ke5eua]

You sir have not experience the blazing speed of a HET, lol Those bunk beds are there because it's going to take you three times as long as it would in a 920.

Once you go 915, you don't go back.

 

[ke5eua]

Ok so what would be the best Allison transmission besides the 654 that would bolt right behind the nhc 250.

Is there any difference in the bell housing between the engines used in the 809 and 939 series?

If I can get an Allison transmission from an old bus and bolt it up I'm fine with it. If drive shaft have to be lengthen or shortened that's fine. I want to make this 818 a unique truck that I know I can drive from central Texas to baton rouge Louisiana and pull a decent load if I wanted to.

The standard transfer is fine for me, and I have no problem dragging the truck to a shop and saying make it work please. I just want to know before hand it will.

 

[Csm Davis]

Okay bud you will want an overdrive transmission or get ready to slow down down the 939 mt654cr is a 1:1 if you are wanting to roll with the big dogs you need a 915 or something else. I have some fun idea's but not sure where you want to get to.

 

[ke5eua]

Okay bud you will want an overdrive transmission or get ready to slow down down the 939 mt654cr is a 1:1 if you are wanting to roll with the big dogs you need a 915 or something else. I have some fun idea's but not sure where you want to get to.

Brett is trying to convience me to get a 915 but I just don't want to loose 6x6. Also if I upgrade to the big boys its gotta be a 1070.

 

[CBR Metalworks]

Get a.916 or 920 and swap 5th wheel. WAY better trucks than the 1070 or a 5 ton.

 

[ke5eua]

Get a.916 or 920 and swap 5th wheel. WAY better trucks than the 1070 or a 5 ton.

As someone who has spent months at a time in a 1070, along with a 931 and 1088, and last but not least a pls I so much prefer the 1070.

Just have to find a cat dealer and Allison dealer willing to reprogram the entire drive system to allow for 60-65 mph.

 

[CBR Metalworks]

I guess I should have said a 915-920 is a much more feasible truck than a 1070 for the average user. I have driven a 1070, I would not trade my 920 for one.

 

[ke5eua]

I guess I should have said a 915-920 is a much more feasible truck than a 1070 for the average user. I have driven a 1070, I would not trade my 920 for one.

That I completely agree with.

 

[Csm Davis]

Well the question remains, what do you plan on doing with it? Personal play thing, do anything you want, cost effective hauler 915, 916, 920 if you are doing any offroad equipment movement.
1070 is way cool but I think overkill for 99% of us I think a 818 with a 8.3cta and a 7 speed Allison would be really nice but there's not really enough space to fit a 7 speed with the 855 ci. Turn a 813 in to a tractor then you'll have room for any drivetrain you like.

 

[Recovry4x4]

Purely from a financial viewpoint, you may have more invested in converting to a juice tranny then an M931 would cost. Also, if you want unique, start with a cargo truck, move the axles back to the rear of the frame and have a long wheelbase tractor. Might even have enough room for an S318 behind the cab as a dromedary.

 

[ke5eua]

I am going to look at getting an Allison 5 speed or 7 speed to slap behind the NHC 250 then work out the transfer situation. Drive shafts will have to be modified but that's no biggie.

As fuzzy said, I'll have a XM818E1, lol