M720 or M832

[2deuce]

Which dolly would be best to carry a S-280 shelter. Is the M720 better behind a pickup, and the M832 better behind a M35a2? Are the top speeds the same? Is one more inherently stable at speed? Appreciate your thoughts, on what to look for.

 

[Coug]

Both are air operated brakes, so without modification neither is suitable for towing behind a pickup, but both would be suitable behind the M35a2.

 

[2deuce]

It seems like I saw one pulled behind a CUCV. I have a M35a2 so I liked the idea of the wheels and tires being the same on the M832, but don't know why the 2 models were made. The M832 looks more HD, but don't know if one has better features, or quality than the other.
Thanks

 

[Coug]

If a CUCV was pulling one, then either it was heavily modified, or an idiot.

I have an M720 over in my back field I bought from one of the other guys around here.
It's certainly heavy enough on it's own. I helped recover a shelter with another one, and it took 3-4 people to maneuver each half to get them attached.

The M720 itself has markings and rating up to I think 10 or 12k or more lbs, even though the Army only rates it for about 6k I believe. I don't think any of the CUCV series is rated to tow that much weight, even without the air brake issue.

The front and rear dollies are separate brake systems, so if doing an electric over hydraulic conversion would require 2 controllers.

I never found anything for converting the brakes over to electric, and after taking one apart it looks like you'd have to have new spindles welded on, so another expensive route to take.


If I were to do one to tow behind a larger truck, and everything else being the same, I'd probably opt for the M832. It uses the same tires as the deuce from what I've read, plus being a little larger/heavier built isn't a bad thing if you have a truck big enough to pull it.
M720 basically uses jeep size tires, a bit lighter duty

 

[2deuce]

I was just going to put my shelter in the back of my Deuce, but then thought it may be interesting to have the option to tow it. I do have a M1028 but wasn't thinking I would use that. The weight of the S-280 wouldn't be too much to tow by either truck, but without brakes not too good. A surge brake conversion may be easier to do. I think both dollies are air over hydraulic. One axle braking is what my trailers have. That said I think the M35 is what I would use. I remember these dollies for sale at Gov Liquidation years ago going for scrap prices.

 

[2deuce]

Is there mounting hardware that is specific to each model, and the differences such that the shelter is built for only one of the dollies? I'm having trouble finding info on attachments, and why there are 2 different dollies. Thanks

 

[Coug]

Looking through the interwebs, both are designed for the S280 shelter. Only real difference is the 720 has a max gross of 6k (or 8k for the M720HD version) and the M832 has a max of 20k lbs.

Wenzlau Engineering | M-720

Wenzlau Engineering, Inc. was established in 1956 to provide engineering solutions for the protection and mobilization of sophisticated electronic systems. We remain focused on our initial mission to provide each customer with a single source for mobile products and services resulting in a...

www.wenzlau.com

Wenzlau Engineering | M-832

Wenzlau Engineering, Inc. was established in 1956 to provide engineering solutions for the protection and mobilization of sophisticated electronic systems. We remain focused on our initial mission to provide each customer with a single source for mobile products and services resulting in a...

www.wenzlau.com

 

[2deuce]

Thanks for the links. It's odd that the picture on the M832 link is of the M720. They also mention mechanical lockout struts for the M720. What are those? I have tried to figure out how the M832 attaches, because it looks quite different than the M720. It looks like the M832 is wider. That and how is the back half of the M832 moved around? The M720 has a tube, and I see where something similar is used on a M840 to move the axle, but the M832, I can't tell.

 

[jeffhuey1n]

I have a tow dolly(?) not too sure what it’s supposed to lift. Neither shelter I own can hook up to it. Until I saw this thread, I completely forgot that I had one. Guess I need to brave the snow, ice and freezing winds to get to its place of storage.

 

[2deuce]

Don't forget the flashlight!
But seriously, I can't find much out about them. I don't think they get used too much. I did watch a video(YouTube) on a M720 with a shelter. It was helpful, but not anything in how the 2 dollies differ.
The shelter I have does have the attachment points for the M720 the best I can tell. I think if I had a choice between the 2...M720 and M832, I'd go for the M832 because it is HD and has Deuce tires. I'm afraid the M832 may be more difficult to use. I don't see a good way to move the rear half in position, and it is heavier than the M720.

 

[2deuce]

So I bought a M720 and brought it home yesterday. It was about a 4hr trip at 60mph counting stops to check on it. It tracked perfectly but one tire was cracked from being flat a very long time. Blew it up to 50#'s and hoped for the best since Les Schwab Tires didn't carry any in stock.
There is a spring loaded pin attached to the tongue, and a corresponding slot in the front axle so that the axle is held straight and rigid. That pin appears should slide into it. The problem is the pin isn't long enough. It looks like that when the tongue is lowered to your hitch a bracket comes in contact with the spring loaded pin and is intended to push it into the slot on the axle. If that is the case the axle would not pivot, and turn, and you would need it to if the dolly was loaded with a shelter. I pushed the pin into that slot, and held it with something I found in my truck. I'm wondering how it was designed and what I have missing, because that pin has no use that I can see as it is. Possibly there isa short pin that is manually inserted between the bracket and the existing pin. Does anybody know? (I can post a picture if anyone is interested in what I did, or it isn't clear what I'm talking about.)

Thanks

 

[2deuce]

2nd question, upon looking over the unit it has 4 air bags. They all look old, but one is older and harder than the others. Are there replacements available?
Thanks