M101A1 Axle

Jshields

Member
I'm new here so excuse my ignorance. I am looking at converting my M101A1 trailer to a overland style trailer. I want to change the axle. Should I go 3.5K or 5K axle? Also what length are you guys using? Going to be 6x5.5 bolt pattern. Any help would be great.
 

4lowdean

Observer
You're most likely going to be ordering a custom axle, so here's my suggestion:

Order a 3500# axle with 4500# spindles in whatever width matches your tow-rig. I think can get 6x5.5 bolt pattern in the larger hub size. I spec'd out a custom Dexter like that for my Jeep and it wasn't too bad.
 

old_CWO

Well-known member
I did one about ten years ago and used a 5200 LB axle with 8 lug electric brakes. I seem to recall that it was the same diameter as the stock axle so the mounting hardware all swapped over. At the time there was not a huge price difference between the 5200 and 3500 so it made sense to go for the beefier bearings and spindles. It doesn't even really weigh that much more.
 
My specs... YMM

Straight 3500#
60" hub to hub (I am using spacers too)
43.25" spring center
electric brakes
Straight ez lube spindles
6x5.5 bolt pattern
Spring pads on top for 2" Springs
3" Tube Upgrade so it bolts up.
Manual Parking Brake

I went 3500 because it matches the data plate and that is what I am registered for and I was able to upgrade to a 3" tube so win all around for me.

Back in 2016 this was about $300ish picked up at my local trailer supply.

I reused the shock mounts from the original axle and had to figure out how to make the parking brakes work with the existing handles, other wise it was a simple swap.
 

Jshields

Member
My specs... YMM

Straight 3500#
60" hub to hub (I am using spacers too)
43.25" spring center
electric brakes
Straight ez lube spindles
6x5.5 bolt pattern
Spring pads on top for 2" Springs
3" Tube Upgrade so it bolts up.
Manual Parking Brake

I went 3500 because it matches the data plate and that is what I am registered for and I was able to upgrade to a 3" tube so win all around for me.

Back in 2016 this was about $300ish picked up at my local trailer supply.

I reused the shock mounts from the original axle and had to figure out how to make the parking brakes work with the existing handles, other wise it was a simple swap.
I looked at this same set up and shipped to me it was going to be a little over $400. My biggest obstacle is what length to order. Want to run the same wheels that I do on my Tacoma 16x8 with -10 offset. 285/75/16 tires
 

old_CWO

Well-known member
I looked at this same set up and shipped to me it was going to be a little over $400. My biggest obstacle is what length to order. Want to run the same wheels that I do on my Tacoma 16x8 with -10 offset. 285/75/16 tires
Take one of you Tacoma wheels off, lay it down on a flat smooth surface like the garage floor. Measure from the floor to the mounting flange of the wheel. Multiply that measurement by 2, add it to the width of the trailer tub at the inner fender wells. That number plus 3" is your starting axle WMS to WMS. You can go wider obviously, but I wouldn't go much narrower than 1.5" clearance to the trailer body.

One bit of advice before you start: Most M101 series trailers are less than 48 between the fender wells - something like 45 if I remember right. In my opinion that is an Achilles heel on a trailer this size and capacity. I would strongly suggest moving the fenders out to at least 50" between the wells before settling on axle dimension. If you ever wanted to carry a 4 Wheel camper, 4x8 sheets of drywall or an ATV you will be glad you did it. The welds holding the fenders cut out pretty easy and then they can be slid out a little and re-welded. You would need a couple of fill plates for the floor of course. No biggie.

It will look a bit like a factory M101A3 when you're done and you will have a much more practical trailer. I personally would never own another M101 without that mod.
 

Jshields

Member
Take one of you Tacoma wheels off, lay it down on a flat smooth surface like the garage floor. Measure from the floor to the mounting flange of the wheel. Multiply that measurement by 2, add it to the width of the trailer tub at the inner fender wells. That number plus 3" is your starting axle WMS to WMS. You can go wider obviously, but I wouldn't go much narrower than 1.5" clearance to the trailer body.

One bit of advice before you start: Most M101 series trailers are less than 48 between the fender wells - something like 45 if I remember right. In my opinion that is an Achilles heel on a trailer this size and capacity. I would strongly suggest moving the fenders out to at least 50" between the wells before settling on axle dimension. If you ever wanted to carry a 4 Wheel camper, 4x8 sheets of drywall or an ATV you will be glad you did it. The welds holding the fenders cut out pretty easy and then they can be slid out a little and re-welded. You would need a couple of fill plates for the floor of course. No biggie.

It will look a bit like a factory M101A3 when you're done and you will have a much more practical trailer. I personally would never own another M101 without that mod.
I never even thought of that. I'm definitely going to do that. Another good reason to buy a welder lol. Thanks
 

4lowdean

Observer
It will look a bit like a factory M101A3 when you're done and you will have a much more practical trailer. I personally would never own another M101 without that mod.
And here I was thinking my other M101A3 was too wide. But I tow it behind a Jeep, so I like my M101A2 in stock width. The tub is the exact same width as my jeep is with the wider fender flares. And I run an axle the same width as the Jeep (60"). If anything, I'd just widen the inside tub without pushing the fenders out since the Jeep tires I run are a lot narrower than the stock mil-spec tires.
 

old_CWO

Well-known member
If anything, I'd just widen the inside tub without pushing the fenders out since the Jeep tires I run are a lot narrower than the stock mil-spec tires.
Yes that's a good solution as well, just section the fender a little and run skinnier tires. OP wants to run 285 mm wide meats; without one on hand to measure I am guessing there isn't room there to narrow it and fit the wide tires. Simple check with a tape measure would prove it out for sure.

The 45" between the wells is the core issue and there's more than one way to skin that cat. I stand by my assertion, any future M101 series in my fleet would need to capable of hauling 4x8 sheet good flat on the floor.

Isn't that M101A3 really wide, something like 55" between the wells wide and big honkin' hummer tires? I can see that being bulky behind a Jeep. Pretty sure my old M101A2 came with 235/85R16s which is fairly large for a trailer but nothing like those 37s.
 
Yep, that number between the wheel wells sucks for a utility trailer. Without experiencing it people would never guess a trailer that size would be that way.

My trailer was a hodge-podge. A3 chassis with an A2 body.

 

Jshields

Member
Take one of you Tacoma wheels off, lay it down on a flat smooth surface like the garage floor. Measure from the floor to the mounting flange of the wheel. Multiply that measurement by 2, add it to the width of the trailer tub at the inner fender wells. That number plus 3" is your starting axle WMS to WMS. You can go wider obviously, but I wouldn't go much narrower than 1.5" clearance to the trailer body.

One bit of advice before you start: Most M101 series trailers are less than 48 between the fender wells - something like 45 if I remember right. In my opinion that is an Achilles heel on a trailer this size and capacity. I would strongly suggest moving the fenders out to at least 50" between the wells before settling on axle dimension. If you ever wanted to carry a 4 Wheel camper, 4x8 sheets of drywall or an ATV you will be glad you did it. The welds holding the fenders cut out pretty easy and then they can be slid out a little and re-welded. You would need a couple of fill plates for the floor of course. No biggie.

It will look a bit like a factory M101A3 when you're done and you will have a much more practical trailer. I personally would never own another M101 without that mod.
Thanks. I'm going to do the 50" space suggestion. Looking like I may go with 66-67" hub face-hub face. Trying to plan ahead if I ever go to 12.5 wide tires. I'm running -10 offset on my wheels but figured for 0 offset just to be safe lol.
 

Jshields

Member
So I got what I feel is a pretty good price for a 66" Dexter #5000 axle, 6x5.5 bolt pattern with electric brakes and top mount spring perches. $460 shipped unassembled.
 

4lowdean

Observer
So I got what I feel is a pretty good price for a 66" Dexter #5000 axle, 6x5.5 bolt pattern with electric brakes and top mount spring perches. $460 shipped unassembled.
Sounds about what mine spec'd out as. I made sure to upgrade to the manual parking brakes. I hope you did too.
 

Jshields

Member
Sounds about what mine spec'd out as. I made sure to upgrade to the manual parking brakes. I hope you did too.
I haven't ordered it yet. I've been debating on that. The trailer o got set for years and the parking brake handles are pretty seized up. Debating whether it's worth messing with.
 
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