Allison M916 + Mk48 Cab = 6x6 "FEMTT"

[demetheis]

Thanks for the entertaining read! It's amazing to see the "finished" truck next to stock and how far you've taken it. Also love seeing the Scorpion on the back! (Noticed it in the background of one of the videos too.) I've been a fan of your builds since the early 90s. War Wagon and then especially the Scorpion! I always saved the Four Wheeler mags that featured your builds. Never thought I'd see one in person, but only a couple weeks ago I spotted a Scorpion at Costco here in Albuquerque. Needless to say, I was pretty excited and the owner was shocked that I knew so much about it. Anyway, keep up the good work! I'll keep reading the threads and living vicariously, unless of course someone wants to trade me a spare deuce and a half for my Vespa!?

 

[wreckerman893]

Anybody get one of the two HEMMT cabs that went for 1800 bucks in Ohio? They were complete and new in the box.

 

[Strouty]

I just spent hours reading all 101 pages of this thread. Soni your truck is amazing. I just acquired an M931A2 and you are making me have crazy ideas. I am trying to make a utility truck and I was going to bob it, but now I don't know what I am going to do. I am absolutely interested in seeing the fifth wheel module. I also really like the knuckleboom, I have a 10 ton civilian boom truck that I use, but being able to have everything in one compact setup is definitely a nice idea. I have a few questions.

Can you give a link to the actual connectors you bought for the modules? I found the weld on brackets, but not the same connectors.

Second, is the dump body a standard setup from one of the dump truck, or was it something special?

 

[M920]

Out of curiosity what would you say the offroad capabilities are like with the FEMTT vs your signature rig the M920? I know the FEMTT has the tire and low CG as an advantage but it seems your M920 was no slouch offroad even with the civi tires.

Well, I have to say that the FEMTT is way superior to the M920A1. This is mostly because of the pusher axle on the M920, that high centers the truck even on relatively small humps! Since it is not a powered axle, it is a major handicap of that truck over 8x8 or 6x6 configurations.

Also, the weight distribution, with a lot of front axle weight and a low CG, makes the FEMTT a great climber!

I can't wait to get the Oshkosh 55000, two speed transfer case installed. The ability to go slower, will definitely make the FEMTT even more controllable and off road capable!

Soni

 

[M920]

Did you make the trip?

Yes I sure did....holly crap, that was one big antenna mast! It made the FEMTT look all tiny.....

Here are some pics:

Soni

 

[M920]

FEMTT Video

Here is a short video of the FEMTT at the last, sharp curve, getting to the top of "Rabbit Peak" in northern New Mexico:

Soni

http://youtu.be/oJhFtXIZTbE

 

[zebedee]

Got "This Video is Private" when I tried to view it... Not sure what that means re your upload etc.

Glad you are getting work for the old girl, makes it all worth while!

 

[Strouty]

Soni,

What is the GVW difference between a 939 and your truck? After removing the tag axle, would they be similar? I do similar jobs, except I am on the opposite end of the country. I know Patracy has done one on an 939, but it seems that he is not using it for a primary work vehicle. There are many differences between the trucks, engine, GVW, transmissions, axles. I do not need to be able to do 80 MPH, but 70 would be nice, I am planning on adding a MD 3060 transmission and possibly go with bigger tires. I just don't know if the 939 is the truck I should start with or if I should wait until I get something more like your truck. What are your suggestions?

 

[patracy]

Soni,

What is the GVW difference between a 939 and your truck? After removing the tag axle, would they be similar? I do similar jobs, except I am on the opposite end of the country. I know Patracy has done one on an 939, but it seems that he is not using it for a primary work vehicle. There are many differences between the trucks, engine, GVW, transmissions, axles. I do not need to be able to do 80 MPH, but 70 would be nice, I am planning on adding a MD 3060 transmission and possibly go with bigger tires. I just don't know if the 939 is the truck I should start with or if I should wait until I get something more like your truck. What are your suggestions?

No question about it, mine is just for play. But if you're going to really be working it day in and day out, the M920 platform is a better start. The SEMTT can do 72mph according to the GPS speedo. But the 250 is screaming along at 2350rpm. I cruise at about 60mph and 1900rpm. (At least pre-turbo I did. I need a longer road session to see where it likes now) 55mph and 1800rpm would be a better cruise speed.

The M939 series is going to be gear bound without a different transmission. And you're stuck with the 6.44 ratio in the axles unless you change them. Now, the 8.3 can spin a higher RPM safely than the 250. And with some mods to the pump, injectors, and a turbo swap, you could get it to 400hp safely and 2500rpm. That'd open up 77mph top speed with the 654r transmission. But even then, you're going to be stressing the transmission and t-case.

So with all that said. If you can live with a 60-65mph cruise speed, I think the M939 series is a more affordable option if you understand the limits. The M920 series though is a better platform to start with for work, speed, power, exc.

 

[Strouty]

I will probably start looking for a 920 series, I really wanted to bob the 5 ton anyways. The funny thing is that I thought the 5 speed auto had overdrive, so when I change in the 6 speed it ends up with two overdrive gears. Reverse won't be as harsh on the transfer case either. I pulled the donor truck around to the front of the shop last night, I am not sure exactly how I am going to proceed at this point. Adjustments and governor springs are definitely going to be a mod, this will end up being a winter project for me. Luckily the 939 fits in my shop.

 

[patracy]

The 654 trans is a 5 speed. But 5th is 1:1.

[FONT=Verdana,Arial,Helvetica][FONT=Verdana,Arial,Helvetica]Ratios (MT-654CR): 4.17:1, 2.21:1, 1.66:1, 1.27:1, 1.00:1, -10.76:1
Max input power: 300
Max input torque (MT-654CR): 950 lb/ft
Input speed (MT-654CR): 1,800-3,000 rpm
Torque converter ratios (MT-654CR): 2.21:1 (TC-495), 2.70:1 (TC-497) [/FONT][/FONT]

 

[Strouty]

I would have never guessed a 5 speed auto was not an overdrive, it makes my trans swap an even better idea. Do you know what ratio the transfer case is? I thought I read that it was overdrive and then low, but I have not confirmed any ratios yet.

 

[patracy]

High is OD in the M939 series t-case. .732. I don't recall low range off the top of my head. But I think it's only like 1.98 or something below 2:1.

 

[M920]

Got "This Video is Private" when I tried to view it... Not sure what that means re your upload etc.

Glad you are getting work for the old girl, makes it all worth while!

Sorry, I forgot to 'publish' it.....thanks!

Soni

 

[M920]

I just spent hours reading all 101 pages of this thread. Soni your truck is amazing. I just acquired an M931A2 and you are making me have crazy ideas. I am trying to make a utility truck and I was going to bob it, but now I don't know what I am going to do. I am absolutely interested in seeing the fifth wheel module. I also really like the knuckleboom, I have a 10 ton civilian boom truck that I use, but being able to have everything in one compact setup is definitely a nice idea. I have a few questions.

Can you give a link to the actual connectors you bought for the modules? I found the weld on brackets, but not the same connectors.

Second, is the dump body a standard setup from one of the dump truck, or was it something special?

Thank you! I'm glad you like the thread.

The twist lock connectors are from a company named 'Chassis King'. Here is a link: www.chassisking.com › Parts

The dump body is off of a USMC Oshkosh MTVR Mk23 dump truck.

Soni

 

[Shark Bait]

Yes I sure did....holly crap, that was one big antenna mast! It made the FEMTT look all tiny.....

Here are some pics:

Soni

How many phone calls to 911 about the "crazy guy" driving around with a cannon or missile on his evil army truck? Lol.

Dave

 

[Strouty]

Thank you! I'm glad you like the thread.

The twist lock connectors are from a company named 'Chassis King'. Here is a link: www.chassisking.com › Parts

The dump body is off of a USMC Oshkosh MTVR Mk23 dump truck.



Soni

Do you have part numbers or at least what they are called? I have been searching the site and have not found them yet. Everything that I think they would be ends up being some obscure part.

I am really waiting to see how you do the fifth wheel module, hint, hint.

 

[M920]

How many phone calls to 911 about the "crazy guy" driving around with a cannon or missile on his evil army truck? Lol.

Dave

Yeah....we thought the same thing! Luckily we only hauled it off road up to the mountain...not sure what the DOT would have said about this load.....lol

Soni

 

[M920]

Do you have part numbers or at least what they are called? I have been searching the site and have not found them yet. Everything that I think they would be ends up being some obscure part.

I am really waiting to see how you do the fifth wheel module, hint, hint.

Try this link: http://www.chassisking.com/attachme...tainer-chassis-chassis-twistlocks-catalog.pdf

Well, I'm working on the fifth wheel module as we speak....I guess I will have to take some pics for you..... lol

 

[Bighurt]

Yeah....we thought the same thing! Luckily we only hauled it off road up to the mountain...not sure what the DOT would have said about this load.....lol

Soni

While there are provisions for loads forward of the front marker lights, I think those only apply to "Cranes" and it's not considered the load.

The rear was definitely not marked properly...LOL