XM983 idea

[jh1990]

Hey everybody,
I have this idea, I would like to build a replica M983 HEMTT truck tractor. I came up with a design for a single steer 8x6 with a lift axle. I would like to use M821/812 Bridge truck axles, frame and transfer. Add the 900 series air brake system to the 821/812 axles. Then find a wrecked civy dump truck and 'borrow' the lifting essembly for the lift axle. I'm planning on using the 8v91 Detroit motor (I think that's the motor in the HEMTT's, please correct me if I'm wrong). With maybe a 10 sp Allison. I'm just thinking about it, no permenit plans will be made for atleast 2-3 years. I'm open to suggestion, basicly just wondering if anyone thinks this is do-able.
Thanks.
P.S.
Does anybody kno if you can find 14.00X20 XL's or if they are even made? Thanks.

 

[M1075]

Hey everybody,
I have this idea, I would like to build a replica M983 HEMTT truck tractor. I came up with a design for a single steer 8x6 with a lift axle. I would like to use M821/812 Bridge truck axles, frame and transfer. Add the 900 series air brake system to the 821/812 axles. Then find a wrecked civy dump truck and 'borrow' the lifting essembly for the lift axle. I'm planning on using the 8v91 Detroit motor (I think that's the motor in the HEMTT's, please correct me if I'm wrong). With maybe a 10 sp Allison. I'm just thinking about it, no permenit plans will be made for atleast 2-3 years. I'm open to suggestion, basicly just wondering if anyone thinks this is do-able.
Thanks.
P.S.
Does anybody kno if you can find 14.00X20 XL's or if they are even made? Thanks.

Sounds like an ambitious plan. I have an alternate suggestion. Just go and get a HET M911. It is already configured as a single steer 8x6 with lift axle, air brakes, 8V92 detroit, and allison auto tranny. Tires are 14.00R24.

No problem finding 14.00R20 XLs. There are thousands upon thousands available surplus.

 

[rmgill]

RE: Re: XM983 idea

Four axle front steer shouldn't be too hard or you could be sneaky and make the rear axle steer with the middle pair fixed like a lot of soviet gear.

 

[jh1990]

Hey everybody,
I have this idea, I would like to build a replica M983 HEMTT truck tractor. I came up with a design for a single steer 8x6 with a lift axle. I would like to use M821/812 Bridge truck axles, frame and transfer. Add the 900 series air brake system to the 821/812 axles. Then find a wrecked civy dump truck and 'borrow' the lifting essembly for the lift axle. I'm planning on using the 8v91 Detroit motor (I think that's the motor in the HEMTT's, please correct me if I'm wrong). With maybe a 10 sp Allison. I'm just thinking about it, no permenit plans will be made for atleast 2-3 years. I'm open to suggestion, basicly just wondering if anyone thinks this is do-able.
Thanks.
P.S.
Does anybody kno if you can find 14.00X20 XL's or if they are even made? Thanks.

Sounds like an ambitious plan. I have an alternate suggestion. Just go and get a HET M911. It is already configured as a single steer 8x6 with lift axle, air brakes, 8V92 detroit, and allison auto tranny. Tires are 14.00R24.

No problem finding 14.00R20 XLs. There are thousands upon thousands available surplus.

Thanks for the suggestion, but aren't the M911's over width? Plus I enjoy challenges seeing as I plan a career as an Army Ranger/SF. Though a HET would be pretty cool to have sitting in the driveway. Thanks again.

rmgill wrote:
Four axle front steer shouldn't be too hard or you could be sneaky and make the rear axle steer with the middle pair fixed like a lot of soviet gear.

First and forth steer, that would be pretty nifty but that's a little to much of a challenge for me, and besides who copies a bunch of communistic stuff Thanks for the suggestions, I've been working on another design when I have some down time at school. Hopefully I'll get that up here sooner then later.

 

[73m819]

RE: Re: XM983 idea

wouldnt it be better just find another xm977 to be a xm983 in the future, the 5 axle pls trucks ,the two front axles steer and so does the rear

 

[Hookin1]

you know they make a steering lift axel.....it follows the truck when its down you could put it right behind the steer axel....the only problem is it dos'nt work going backwards..

 

[maddawg308]

By the time you built the beast, you could've paid the same money for a real HEMTT. My two cents, just seems like a s**t load of work to get something you want...

 

[jh1990]

Re: RE: Re: XM983 idea

wouldnt it be better just find another xm977 to be a xm983 in the future, the 5 axle pls trucks ,the two front axles steer and so does the rear

That maybe an option, but aren't most of the M977's still in service? Also the price, I'm not willing to fork over a hunk of bengies at one time to have it right away. I want a large project that will take a few years to complete. Tim Taylor has his hot rods, I have massive MV replicas .

you know they make a steering lift axel.....it follows the truck when its down you could put it right behind the steer axel....the only problem is it dos'nt work going backwards..

No I didn't know there was such a thing, but if it isn't to good backwards then it doesn't sound that practical, but then again my whole idea isn't that practical. Thanks for the suggestions guys...I'll try to work on a parts list and post it. Suggestions are much appreciated

 

[73m819]

RE: Re: RE: Re: XM983 idea

not the XM977, thats what i bought, it will in sometime in the furture be turned into a xm983, i could most likly pull the pc&f cab and bolt a hemtt cab on, though thats not my plan

 

[jh1990]

RE: Re: RE: Re: XM983 idea

73m819-you have the cargo version, correct?

 

[73m819]

RE: Re: RE: Re: XM983 idea

yep a xm977 not a m977

 

[jh1990]

RE: Re: RE: Re: XM983 idea

now whats on the xm977 thats not on the m977?

 

[73m819]

RE: Re: RE: Re: XM983 idea

a PC&F cab ,s cam brakes not sure what ealse, have not checked the hemtt manuals yet

 

[jh1990]

RE: Re: RE: Re: XM983 idea

Are you planning to pull the bed, crane and all what not and put a slider plate and 5th wheel?

 

[73m819]

RE: Re: RE: Re: XM983 idea

it has no bed or crane

 

[maddawg308]

RE: Re: RE: Re: XM983 idea

Hey, how come you don't move the up-down axle further towards the cab, with the fuel tank behind it, like the real one? It would look closer to the original.

 

[jh1990]

RE: Re: RE: Re: XM983 idea

it would yes, but I'm not sure how it would effect the steering, someone earlier said about a lift axle that would steer, but not backwards. I really don't know why I want the lift axle behind the fuel tank, plus if the lift axle was in front of the fuel tank then I would have to either raise the fender or cut it out at that point or run a smaller tire which might not look like it almost should.

 

[rmgill]

RE: Re: RE: Re: XM983 idea

What's wrong with making the front axle steer? The linkage is pretty straight forwards. You'd have to go with a new set of control arms shorter for the right ratio, but you could add either a single or a double set of links from the front wheels up to the frame and then back down to the wheels to make it all link correctly I think. I remember looking at the linkage for the British 6x6 Saracen and Saladin vehicles and that 6x6 front 4 wheel steering linkage was the simplest thing on the whole family of vehicles.

 

[jh1990]

RE: Re: RE: Re: XM983 idea

theres nothing wrong with making the front axle steer, it's just making the front PLUS the rearmost axle steer. What for motor do you guys think would be the best? just looking for suggestions.