Posted by David Sherman on Sunday, May 29, 2005 at 1:08PM :
In Reply to: trailer i.d. needed posted by Doc Dave on Sunday, May 29, 2005 at 8:02AM :
If those are 6-lug budd rims, it's probably an M105 1.5-ton trailer. Rated 3000 lbs cargo capacity off-road. Normally runs 9.00-20 tires. This is the "correct" trailer for the M35 2.5 ton (off-road) truck and uses not only the same tires, but the same hub, drum, and brake assemblies. It looks like it has the old style lights, which probably means that there is no running light in the right-hand lamp assembly. I have one like that (an XM-105, according to the data plate) and had to explain that to cops a couple times. Fortunately they let me go with it, but technically you're supposed to have tail lights on both sides nowadays. There's no wire in the harness for a right-hand marker light so it's not simply a matter of swapping in a new composite light. I also had to jerry-rig the wiring and modify the housing to turn one of the blackout lights into a right turn signal indicator. I figured I could run with only a left-side tail light, but had best have two working turn signals.
The unit underneath is the brake actuator. Air in the service brake line actuates a diaphragm that actuates a master cylinder on the trailer. The ammo trailers, built on a similar chassis, have two air lines, more like a modern semi-trailer setup, and an air tank on the trailer such that if the service line breaks the brakes will actuate. As a practical matter, a loaded M105 trailer is light enough compared to even an empty M35 truck, that trailer brakes really only necessary to prevent jacknifing on ice. Incidentally, the old guy at my local NAPA recognized the master cylinder as being the same as a 30s Chevy, and had rebuild kits in stock for it. I have 5 M105s and had to rebuild the MCs on most of them. The mechanism seems to get snagged on stumps or rocks a lot (probably why they were sent to the DRMO) or the fluid drains out and nobody checks or notices it, and then the MC gets rusty and doesn't work. It's an easy fix.
Don't know why somebody put 7.50-20s on it. Probably just what they had laying around.
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