M116A3 Build

[lfhoward]

If you did not recalibrate your speedo after the tire size change your mileage may not be as bad as you think. Bigger tires roll further per rev. That's about a 5/ct difference in roll out, or about 3/4 mile in 15.

On the trailer tires the weight takes more energy to get rolling, but the big hard tires with little sidewall flex may actually roll easier with a light load than a similarly sized softer LT tire once they are up and rolling. I'm surprised that they spec with such a low tire pressure (maybe the 30 psi is a minimum?). Usually big heavy truck tires run very high pressures compared to LT or car tires.

The speedometer in the Jeep isn't recalibrated, but I did calibrate my Scangauge to display correct speed and mpg, so the numbers are accurate. The 12.2 mpg figure came from miles driven (corrected for tire size) / gallons used when I filled up yesterday.

It is interesting that those bias ply hummer tires max out at 30 lbs. Without the steel belts that radials have, they can't take the higher pressures. It is sort of like riding on balloons!

[lfhoward]

The second coat of urethane is on as of this afternoon! It sure does make the wood grain look beautiful.

[Alan_H]

No one has mentioned this yet, so I'll throw it out there...

I would go with the civilian wheel option. I understand your thinking on hoping for an A/T tire, but I wouldn't hold out for that. I would rather have a good set of wheels with no tires, even if I have to paint them, than waiting for a set of wheels with tires, and ending up with wheels that are all rusted inside the tire due to excessive moisture.

Concentrate on the Wheels... tires are an extra bonus if you find them. You can always find decent used A/T tires, which is all you should need for your trailer, instead of buying new tires that are going to sit 80%+ of the year. These aren't drive tires...

Just my $0.02

So, after my journey to central PA for the solar panel and aluminum sheeting, I got a good sense of how the trailer pulled behind my Jeep. My overall impression was good, but there are some things that have bugged me in retrospect.

1) The shimmy at 55+ mph. The military tires are 36" bias ply monsters that are not balanced, and I don't think the military even does that, as the service manual says to drive no faster than 55. I had them up to 70, and the rotational resonance peaked at about 56-64 mph. The shaking wasn't as bad as when the trailer was empty (when I brought it home from VA) but it was still there.

2) One of the tires doesn't seem to be able to hold pressure and it is very badly dry-rotted. I pumped the tires up to 26 psi before leaving on my trip (the service manual says these tires are maxed out at 30 psi with a full load on the trailer), but by the next morning the pressure hardly registered. The other tire holds pressure well but looks like a fairly recent retread (possibly unbalanced too).

3) The gas mileage I got pulling my trailer was not too good. Using tow/haul mode, I averaged 12.2 mpg on that tank. One reason for that is probably the immensely heavy run-flat military tires and beadlock rims. Of course, I was towing a brick with a brick. But I was hoping for 13-14 mpg.


I've been looking into options. The military rims are 16.5 inches in diameter, a 8x6.5 bolt pattern, and are 8-bolt beadlocks. There are a few issues here.

1) The older bias ply humvee tires are very hard to find replacements for, even though the newer radial humvee tires are readily available. I haven't been able to find a matching one in my area.

2) The 8-bolt beadlock rims are too weak to run newer humvee radial tires (the minor issue of exploding rims) and the newer humvee rims have 16 bolts holding the beadlocks together. So, to run newer humvee tires I would have to get two of them and upgrade my rims also. $$$

3) I thought of running civillian tires on the military rims, but 16.5 inch rims are no longer used on any modern vehicles. Back in the 70's and 80's they were fairly common, but now there are only a few tire types even made for them. Super Swampers are one type, but I don't want those. All the 16.5 tires on Craigslist are so old they are dry rotted to crap.

4) This brings me to new civillian rims. 8x6.5 bolt pattern rims used to be the norm on GMC/Chevy 2500 pickups and vans, Ford F250 and E250 trucks/vans, and Dodge Ram 2500's as recently as 2009. I think the big three started using a different bolt pattern beginning around 2010 (at least for GM), but cheap 3/4 ton truck rims with an 8x6.5 bolt pattern are pretty widely available on Craigslist. I've seen them with decent used tires for fairly low prices, so I think I'm going to try to find some 16 inch civillian rims for my trailer. Hopefully I can get them with reasonable A/T tires already mounted on them.

It will be an experiment. In the best case, new rims/tires would reliably hold pressure, make the ride smoother, and give me back 1-2 mpg from lower tire weight and slightly lower trailer height (if I'm running 31's, 32's or 33's instead of the military 36's). I'd settle for 2 out of the 3!

[lfhoward]

Tonight I measured, cut, and drilled the frame pieces for the rear door. Very satisfying indeed.

@Alan_H:
Good news! I will be picking up a set of 4 GMC 8-lug rims tomorrow after work. The rims come with well-worn (but usable for a trailer) Toyo Open Country A/T tires. They are 265/75R16's, so are just a hair taller than the tires on my Jeep (245/75R16). The difference between the civilian tires and the old military ones is the new tires are 32's vs. the military tires which are 36's, so the trailer will sit about 2 inches lower.

Photo credits go to Jim G. From Craigslist.


These tires don't have much tread left, but do hold air and are not dry rotted.


Because these rims are 16's, the tires currently on my Jeep will be able to spend their retirement on these rims later on because my Jeep rims are 16's also.

[pchast]

Good find.

[Alan_H]

Good find.

Ditto!!

Plus you will have a matching full-size spare.

[lfhoward]

Thanks everyone. I picked up the tires last night and at least 3 of them look pretty good, which is all I need!

We had a day-long 1-2 inches of rain event yesterday, and unfortunately water got through my tarp. There are probably holes in it that developed from putting it up and taking it down over sharp corners. The whole roof got soaked under the tarp, and there was some drippage through the fan hole and window frames. There is not as much carnage as I would have thought, because of the two coats of spar urethane on there. 99% of the trailer is ok, but two coats is definitely not enough, because there were a couple of places that water seeped through into the plywood. One was on the roof itself, and the other was through the end grain on the sill of the starboard window cut-out. I had some water also come through the front window frames and soak under the foundation from the inside of the trailer too, but there doesn't seem to be any bending of the wood there.

My solution was to towel up as much water as I could get, then fire up the compressor and blow water out of the joints between the wood where it had pooled. That worked to get the free water out, but there is still some water that soaked into the wood itself. I'm hoping a day in the sun will help to flatten out some of those areas (especially the roof). I enlisted the help of a 45 lb kettle bell to encourage the roof to flatten out where it had bubbled up.



So what are it's chances, doc? Any chance the water damage to the sanded pine ply will flatten out reasonably well?

I squirted some TB into the separation in the window frame, then clamped it tight. I think this wood will recover.



I really need to get the aluminum on soon!

[noseoil]

About the roof. I would drill some holes, use some bolts & let the sun do it's thing to bake it before it sets up with the uneven surface. Maybe not the best choice, but it would work. Heat & pressure.

[lfhoward]

About the roof. I would drill some holes, use some bolts & let the sun do it's thing to bake it before it sets up with the uneven surface. Maybe not the best choice, but it would work. Heat & pressure.

Good idea. The kettle bell only works on the upward bulge, but there is an adjacent downward bulge that I didn't know how to deal with. Going out to drill now.

[lfhoward]

Noseoil, your idea did the trick! Here is how it looks now, using some scraps and some left-over grade 5 bolts I had.

Outside:


Inside:


There is still a little upward bulge near the edge, which you can see as a gap between the plywood and the side roof beam. I stuck the 45 lb kettle bell over that in hopes that it settles. I am 99% happy with this solution. Will fill the holes in the roof with PL Premium once everything dries straight.

[Alan_H]

Are you going to paint those wheels OD Green to match the trailer?

[lfhoward]

Here's the difference:

Are you going to paint those wheels OD Green to match the trailer?

Perhaps. I'll have to see how the whole trailer turns out before I paint the wheels or the fenders.

[lfhoward]

Today I beat the rain until about 3:00, then the thunderstorms arrived. I had enough time to make a door!



I also experimented with different ways of making my own clamp rings for those windows (like the one you see in the door). It's definitely possible. I made a prototype wooden trim piece with my router that has a lip that catches the aluminum window and holds it in. Those pieces of trim can be screwed into the wooden window frame from the inside. More detail on that later.

[lfhoward]

I practice installed the door latch. This took some careful work with the router, jig saw, and drill. Glad I didn't try it for the first time on the actual door!

[dales133]

Tidy work on the lock,they look good in stainless