fishing for thoughts on a 5 ton 8x8 (fake hemtt) - Steel Soldiers::Military Vehicles Supersite

illtemper · 04-09-2008, 14:31

first off this is just an idea as I really like the hemtt's but know i can never afford one.
I don't even have my first mv home yet, m52a2, but I do have a set of 5 ton axles sittin here,complete with transfer case and drivelines. far far away in the future , I was thinking about putting 2 steer axles on a rear bogie spring setup, just like a regular rear but with steers. I know the steering wouldn't be quite right but should be close enough to work,then just bolt the thing to the frame. for the cab I figured I'd use 2" tube to frame a basic hemtt shape then just skin it.
well any thoughts? again its just a thought, if its been said before just point me in that direction please.I've read a little on the baby hemtt (cool rig),but I like the 8x8 thing.
thanx...jon

M1075 · 04-09-2008, 15:01

It sounds like a lot of work, but the one good thing you have going for you is the ability to power a second front axle with only a driveshaft. Plenty of HEMTT surplus cabs are available so I would look for one of those.

Recovry4x4 · 04-09-2008, 19:06

IIRC there is a M.A.N. wrecker on ebay starting cheap

mhodges · 04-09-2008, 21:03

I've climbed all over the MAN wrecker- it is in ROUGH shape- it's at a junkyard a buddy of mine frequents for cheverolet parts- its in VA beach outside of oceana...had a bunch of pics saved on my phone and planned on posting them back around december, but the phone met an early demise!

wreckerman893 · 04-09-2008, 21:10

Jon,

Evidently great minds do indeed think alike.

I have mentioned the same idea to several people who already think I am crazy.

My idea is to cut the frame with the rear suspension and put it in front of the engine.
Replace the rear axles with steering axles and fab a power steering system
The engine would then be about where it is in a regular HEMMET.
Unless you used the engine/tranny out of a 900 series you would have problems with shifters and linkage.
You could then mount a HEMMET cab over the steering axles just like the real thing.
So many ideas......so little money.

tcody · 04-09-2008, 23:12

Macon - sent you a pm.
Thane

BobS · 04-10-2008, 03:56

TRW and Ross both make light and heavy duty steering gear setups for twin steer's that are available off the shelf. IH (Navistar), Freightliner, Western Star, PACCAR, and others all make twin steers, so make friends with your local dealer. You must have a relay link to tie the 2 steer axles together on the right hand side (assuming you are driving on the left), and the 3 slave gears (if you use a conventional system), or 2 gears (if you attempt to only "steer from one side") require a great deal of hydraulic fluid (quantity or volume, not pressure), so you would need to change to a hi-volume p/s pump.

To prevent extreme understeer, you MUST use an interaxle differential on pavement, or a disconnect to prevent the 2 axles from being forced to rotate at the same speed (do an off-track diagram and you will see why-each wheel tracks on a different raduius and will horrendously scrub.). If you don't plan on plowing through many gardrails and fences as the truck slides the tires, instead of turning (same effect as a conventional 4x4 wit ha Detroit locker in the front axle on pavement).

This ain't a place to cut corners, you WILL die if you screw it up and possibly kill others. An 8x8 is a blast to drive though...

....BTW-shifters for a manual trans and various throttle cables, etc. are no problem-use shifter and clutch parts from a COE Freightliner Argosy. Just get longer cables from Morse.

m.walker · 04-10-2008, 12:59

One problem James , if you do get a cab GL might want it back ! Like mine , I'm pissed !!!

maddawg308 · 04-10-2008, 13:04

Buy a HEMTT cab from a private company. Once it's sold from their lot, GL/FedGov can't ask for it back. I think these guys have a few:

http://www.murphyjunk.bizland.com

BobS · 04-10-2008, 13:38

Addendum to previous message on steering:

I do not want to seem anti-conversion. I am not. A twin steer is a great idea. You can make it ride better, be more controllable, have a higher VCI mobility rating (means tear around offroad more and in worse places), and it also has a whole host of other advantages.

You can increase the accessibility to the drivetrain for servicing when "stuff" happens, have parts that live longer and do not "work as hard".....

All in all, it would be an exciting project.

ADDENDUM 2:

If you have the steer axles now and the suspension, the steering setup from an IH Paystar twin steer would cost you about $2500.00 from a junkyard. Look especially in the oil producing regions of the US and Canada for the parts-one of the biggest users of twin steers is for offroad mobile oil rigs.

As a sidebar, when I was with IH in the 1970's, we built 6 for use in the 3rd world. Great program as I got to go to South Africa and Rhodesia to help out installing the bodies and perform testing.