Tandem trailer using M105 axles build

[tobyS]

I'm beginning a trailer build using (2) M105 axles. I just purchased some motor home tires and wheels, 19.5" budds with 8 x 19.5 tires. Got 6 and will have to find 3-4 more. Would like to have a couple spares. On the axle, they measure outside to outside....8'5"....so real close to the legal limit. Will post a pick with them on an axle tomorrow. I like these tires for highway use better than the single bolsters 12.5 x 16.5's (rims or tires not too available).

It will be a gooseneck and pull behind my deuce 4x4. I'm retaining each axle's air over hydraulic with break away brakes...it works on an M1061.

Suspension......I'm thinking about not using springs with equalizer and just use air bags, where each axle is independant of the other. I do have to make new suspension, the springs and frame mounts are re-purposed on the A3 (back and front) from 2 105's. Please give me any ideas you may think would work really great.

 

[silverstate55]

I’ve got some future trailer projects & upgrades I’d love to tackle someday & have been really fascinated by Australian off-road adventure/overland trailers. The suspensions on these are quite fascinating and Pinterest has LOTS of ideas & inspiration.

Here are some air bag & coil spring ideas:



Here are some trailing arms with wide mounts that virtually eliminate the need for upper control linkages:



Or you could make your own walking-beam style of suspension:



Hope this helps. Good luck, looking forward to seeing pics of your project.

 

[tobyS]

Thanks Silverstate55 for the ideas. Those are really "independant" suspension systems. I've got another project that will be a lot closer to truly independant like the above. It's rear is modeled off the Porsche 914 rear swing arms. It's a VW bug that is getting a supercharged 3800 Pontiac Bonneville engine and tranny as a mid engine.....but I won't distract my own thread or get thrown offagain...I call it my "bug out" project.

By independant, I mean the front axle will not be tied to the rear axle with an equalizer. The arms will be welded like most semi's that use air bags....which really doesn't give much flex side to side. I'm worried that truly independant will allow too much side to side sway. Equipment on top puts the CG higher up too.

That last one "walking beam" is a lot like the M322 but much lighter. It would not sway side to side, but the axle would have to move at the arm joint. The M322 has a full tube axle I think. That is something to think about as I am trying to make a lighter and gooseneck version of the M322. Hmmm

 

[tobyS]

Here is with the bolster rims and tires. It measures 7'6" outside. The 8 x 19.5" is to compare.. The overall width with the 19.5 is 8'2". Found the date codes on the tires....all the same...(1117). Yipeee

My friend with the salvage yard sold me these 19.5's and tires for $20 each. I need 3-4 more but probably won't come close to that price. It frees up 2 bolster rims for 37" hummer tires for the M105.

 

[tobyS]

Silverstate55, I'm making the suspension like the top 3rd (blue) one in your photo's. I'll get a 4x4 or 4x3 tube to go under and weld to the axle. I want to retain the park brake so have to clear the cable coming out of the front of the backing plates. I should be able to get full welds since I can turn it over.

I have 6x10 I beams for the main frame. Without air, the frame will set down to a nice big rubber stop on top of the axle, about 3-4" movement from the ride position. Should be solid for loading.

Length....frame beams are about 34' uncut, so longer deck is possible, if desired. I'm thinking about 22' on the floor and a dovetail about 3', with the axles shifted slightly to the rear like the M322. Or a dovetail that is flat until used (air up-down). Then I wouldn't have ramps folding over into cargo space. When I had an M322, that was a modification I thought would work well.

 

[silverstate55]

That should work quite nicely, can’t wait to see build pics!

 

[INFChief]

I’ve got some future trailer projects & upgrades I’d love to tackle someday & have been really fascinated by Australian off-road adventure/overland trailers. The suspensions on these are quite fascinating and Pinterest has LOTS of ideas & inspiration.

Here are some air bag & coil spring ideas:

View attachment 803094 View attachment 803095 View attachment 803096

Here are some trailing arms with wide mounts that virtually eliminate the need for upper control linkages:

View attachment 803097 View attachment 803098 View attachment 803099 View attachment 803100

Or you could make your own walking-beam style of suspension:

View attachment 803101

Hope this helps. Good luck, looking forward to seeing pics of your project.

What’s the purpose of a walking beam?

 

[Coug]

What’s the purpose of a walking beam?

walking beam axle purpose is to evenly distribute the load between the two sets of tires.

On uneven terrain, the 2 axles pivot on a center point, so they will always have the same amount of ground pressure.

It also means that as you go over obstacles/bumps, the vehicle only lifts up the difference between the front and rear tires, where some other styles would place the full weight of the trailer onto whichever tire is higher elevation of the two.

 

[INFChief]

walking beam axle purpose is to evenly distribute the load between the two sets of tires.

On uneven terrain, the 2 axles pivot on a center point, so they will always have the same amount of ground pressure.

It also means that as you go over obstacles/bumps, the vehicle only lifts up the difference between the front and rear tires, where some other styles would place the full weight of the trailer onto whichever tire is higher elevation of the two.

If I have 2 walking axles (essentially a trunion) 1 for each side, I can mount 4 tires versus 2. This setup allows the axles to better negotiating rough terrain. Are you familiar with what else is needed to install 2 walking beams?