Quad Steering

[KaiserM109]

On my M923 I am considering pulling off both rear axles and putting a steerable axle from the front of a donor truck to give me quad steering. My reason for considering such an undertaking is that I am building an off-road camper and the ’40 acre’ turning radius will be a killer. I am planning to pitch the cargo bed, put the box from my M109 on it and bobbing the frame.

Here are my concerns, and I would appreciate comments:
1) Singles vs Duels. I will have to put on a single wheel, since the spindle wouldn’t work with duels. I don’t think that will cause a weight capacity problem. I am planning on keeping the 11.00 R20 Michelins on it. Possibly I will need to go to ‘super single’ 14.00s.

2) Brake Capacity. The front axle has a single brake actuator on each wheel without a safety spring, while the rear has 2, one with a spring. It looks like I can put a spring actuator on in place of the other, but I am concerned that I won’t have enough stopping power. The total weight of the rig will be only a little more than an unloaded M923.

3) ABS Brakes. The ABS brakes are on the rear. In the TMs on this website are instructions about how the modification was mounted and it looks to me like it might be possible to mount them on a front axle. What would be really great would be if I could put the backing plate and brake assembly from one of the scrap rear axles on the formerly front axle. If they don’t interchange, maybe I could modify the old back ones to fit.

4) Steering Controls. Last but not least, how do I control the steering? I would only want full steering at slow speeds, and then possibly less than the front. There has to be a lock for highway travel.

Let me know what you think or what your experience is.

PS Whatevter I implement HAS to be conservative with regard to safety.

 

[Suprman]

Its my understanding that the lmtv deuce turns pretty tight and your m109 box should fit on the back of that. It would probably be more cost effective to use the newer truck than try to get 4 wheel steering to work on a 923.

 

[KaiserM109]

Its my understanding that the lmtv deuce turns pretty tight and your m109 box should fit on the back of that. It would probably be more cost effective to use the newer truck than try to get 4 wheel steering to work on a 923.

That might have another benefit, my wife HATES my 5 ton!

 

[Suprman]

The lmtv deuce actually comes in a box configuration I just saw a bunch run thru the auction yesterday.

 

[KaiserM109]

Got the URL for that auction?

 

[Suprman]

Its an M1079 I dont think I am allowed to post an auction link

 

[Swamp Donkey]

What about the spring brakes? Front axles only have service brakes.

 

[swbradley1]

Its an M1079 I dont think I am allowed to post an auction link

Active? No

Closed auction links are okay.

 

[tim292stro]

...PS Whatevter I implement HAS to be conservative with regard to safety.

I just want to point out that doing all-steer and the above sentence clash...

There are many ways to do rear-steering - I've been looking at them for my bus project for about a decade. AVOID Oshkosh's HET/HEMTT/PLS steering like the plague if you plan on doing highway driving unloaded. Their system is a fixed counter ratio to the front which at speed makes the rear end want to try to pass the front (i.e. you spin out). GM figured this out in the 1980's when they played with a 4-wheel steered Pontiac Fiero to compete with the Honda Prelude all wheel steering. What needs to happen is that at a critical handling speed, the rear needs to stop counter steering - then over a higher critical handling speed it needs to start steering the same way as the front. GM had Delphi build this into the quadrasteer they offered on a bunch of GMC trucks and SUVs.

Acura has done the same thing as Honda - becasue if you're in Japan, they are the same company (kind of like Datsun and Nissan, Toyota and Lexus... etc.).


Just know that if you put on a non-standard steering system, that was never offered for your vehicle (i.e. DIY), you are solely on the hook for liability. There are companies you can hire to review and comment on your designs who have licensed engineers to CYA. If you don't do that, good luck insuring it. My

 

[steve6x6x6]

6X6 all wheel steer, made these twin screw axles about 14 years ago.

 

[74M35A2]

That might have another benefit, my wife HATES my 5 ton!

I thought mine was the only one.....