M1088 camper conversion

Sandspider

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Where did you get the info on removing a spring? Considering doing the same just concerned about what that means for weigh carrying with a loaded camper box and sway control? if that would even be affected?
 

srodocker

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Wow what a beautiful build! Cant wait to see more. Theres a link in my signature for our PNW Annual Campout in july in Winlock Wa. We post mostly on our FB PAge PNW Steel Soldiers. Again great build
 

ckouba

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Where did you get the info on removing a spring? Considering doing the same just concerned about what that means for weigh carrying with a loaded camper box and sway control? if that would even be affected?
Sandspider-

It was recommended by Quade at Overland Adventure Truck as a better alternative to the lighter (5t) spring pack. It seems to have made the truck's ride very reasonable, almost like a 1 ton pickup. With the air ride of the cab, it almost feels plush. Or at least "truck plush".

Doing the math with the assumption that each leaf is reasonably comparable, removing one of the four leaves on a 12.5t spring pack should leave me around 9t spring capacity. The truck already weighs ~10t, which legally only leaves me ~3t to play with on my license (<26,000#), so that still means I have somewhere around 6t excess capacity in the spring pack. I assume that it will be sufficient, but if it isn't I can also reinstall the leaves. Based on the recommendation, I don't expect that to be necessary though.

Thanks for the invite srodocker. I will see what we're up to and if we can make it.
 
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ckouba

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An update on the truck-

I have a few parallel projects running and the others jumped the truck's priority recently, so haven't been putting the time in as much as I wanted. I have started it up a few times and gone around the block or out for gas, but not too far due to the coolant leak.

What I thought was a heater core issue turned out to be a radiator leak. Presently I have torn it down for access and am trying to figure out a socially distant way of getting help to heave it out. Once it has been repaired and reinstalled, I will be working through the wheel/tire balance shimmy and putting some miles on it to shake it down.

When I posted the render in the first post, we were pretty sold on that layout. We've subsequently seen another one we like pretty well and are now leaning in a slightly different direction. Will post a render when I have one together.

I also picked up one of the Freightliner steering wheels, 18" dia, and have fitted it. I do like the smaller size a bit better but have yet to really get any time behind the wheel to truly evaluate it.

Things still waiting for some love and attention (ie, installation): Cascadia remote and heated mirrors, Fox shocks acquired through Grigsby

I do really miss working on this thing after having made some good progress up front, but that is the nature of this type of project.
 

Sandspider

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Thanks for the info on the spring pack numbers!
I have installed the cascadia mirrors but have not wired them in yet. Trying to figure out the best (sexiest) way to do it, Controllers and placement of them.
What controller did you go with and where do you plan on putting it?
 

Attachments

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Seattle Wa
Thanks for the info on the spring pack numbers!
I have installed the cascadia mirrors but have not wired them in yet. Trying to figure out the best (sexiest) way to do it, Controllers and placement of them.
What controller did you go with and where do you plan on putting it?
Awesome job!!!
What is your plan for the substrate and body mounting of the camper of the back?
With articulation while offroad things could separate, I have seen some spring type body mounts used and a few others.
What will your approach be?
 

ramdough

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Thanks for the info on the spring pack numbers!
I have installed the cascadia mirrors but have not wired them in yet. Trying to figure out the best (sexiest) way to do it, Controllers and placement of them.
What controller did you go with and where do you plan on putting it?
How do you like the mirrors? Are they worth the money?


Sent from my iPhone using Tapatalk
 

Sandspider

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Idaho
Awesome job!!!
What is your plan for the substrate and body mounting of the camper of the back?
With articulation while offroad things could separate, I have seen some spring type body mounts used and a few others.
What will your approach be?
Goose neck ball and greasable receiver in an inverted y on the same plain. The y being two upfront in order to keep the box more inline to the cab for a pass thru and multiple center attachments to distribute weight and create clearance for rear articulation. Contemplating air over gas shocks for an anti sway while on curvy roads, adjustable with air value from cab.
 
58
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Location
Seattle Wa
Goose neck ball and greasable receiver in an inverted y on the same plain. The y being two upfront in order to keep the box more inline to the cab for a pass thru and multiple center attachments to distribute weight and create clearance for rear articulation. Contemplating air over gas shocks for an anti sway while on curvy roads, adjustable with air value from cab.
Sounds good, post a lot of pics along the way of this process if you can, I would be very interested to watch the design unfold...
Thank you for sharing, it helps me put together my plan...
 

ckouba

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And we now return to our regularly scheduled broadcast.....

Some forward progress and some stagnation: radiator was successfully removed, repaired, and replaced. I didn't take many pictures during the process and just followed along with the TM, and it pretty much went right along with how I would have logically done it if I went in blind. There were no tricks, which was nice, and it all went back together fairly easily with just the shroud bolts being finicky.

While I was in there, I discovered I have what appears to be the updated fan (no rubber to degrade and toss a blade into the rad) and I took the opportunity to replace all the belts and check the nut on the compressor (was tight, yay!). All in all, things went well.

Next up, I replaced the OEM shocks with the Fox offerings from Grigsby, which came in from backorder in February.

New shocks:


Where I haven't made progress is in dealing with a persistent shimmy while driving at speed (~55-60 MPH), and I have compelled myself to resolve it prior to moving on to any other chassis work or the actual camper build.

At this point, I have swapped all the tires for the new ones I got when I bought it, had all the driveshafts completely rebuilt, installed the new shocks, rotated the tires through different positions around the truck, and statically balanced all the tire/wheels assemblies on a balancer which I made.

The static balancer:


The balancer is made from VW Bug front hub with an adapter plate I had laser cut from 1/2" steel plate. I added a few studs and things seemed to work out pretty well.

Front view, the taped on spacers were used to make up for brake drum thickness and keep the lug nuts on the threads:


In practice, I mounted up the tire assembly to the drum, let it spin til the heavy side was down and then would move it 90° one way and add weight on the light side until it wouldn't spontaneously spin with gravity. I would then check that it remains static through 360° and adjust accordingly and I had figured this to be good enough to address any major imbalances. The weight I had to apply ranged from ZERO(!!!!) on one assembly to 3.6 pounds, most of them being in the 1-2 pound range. I then used some adhesive to secure the slab of lead to the inner surface of the wheel.

The left rear wheel about to be reinstalled, 2.25# of lead on board:


Despite all this work, I still get to mid-50's mph and there is a pronounced vibration which feels like it's gotten better below that but seems like it's gotten worse once I get there. It almost feels like one of the tires is severely out of round but the shimmy also fades in and out as I progress through bends, which makes me feel like it's phasing in and out with other tires. If it was an out-of-round unit, it wouldn't matter what the speed- it would always be lumpy and I should always feel it.

Speaking of which, while I had them on the balancer, I started checking how concentric the wheels/tires were but managed to forget to do it after the 2nd tire. I was very disappointed when I realized I forgot to keep checking this and I intend to pull them off and check them sometime during the remainder of this week. I anxiously await seeing where that leads me.

If anyone has any suggestions of how to better address the shimmy issue, I am all ears. If I am missing something in my balancing procedure, please point it out to me. I certainly don't feel like an expert but am willing to try anything to knock this out. Thanks in advance!
 
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simp5782

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And we now return to our regularly scheduled broadcast.....

Some forward progress and some stagnation: radiator was successfully removed, repaired, and replaced. I didn't take many pictures during the process and just followed along with the TM, and it pretty much went right along with how I would have logically done it if I went in blind. There were no tricks, which was nice, and it all went back together fairly easily with just the shroud bolts being finicky.

While I was in there, I discovered I have what appears to be the updated fan (no rubber to degrade and toss a blade into the rad) and I took the opportunity to replace all the belts and check the nut on the compressor (was tight, yay!). All in all, things went well.

Next up, I replaced the OEM shocks with the Fox offerings from Grigsby, which came in from backorder in February.

New shocks:


Where I haven't made progress is in dealing with a persistent shimmy while driving at speed (~55-60 MPH), and I have compelled myself to resolve it prior to moving on to any other chassis work or the actual camper build.

At this point, I have swapped all the tires for the new ones I got when I bought it, had all the driveshafts completely rebuilt, installed the new shocks, rotated the tires through different positions around the truck, and statically balanced all the tire/wheels assemblies on a balancer which I made.

The static balancer:


The balancer is made from VW Bug front hub with an adapter plate I had laser cut from 1/2" steel plate. I added a few studs and things seemed to work out pretty well.

Front view, the taped on spacers were used to make up for brake drum thickness and keep the lug nuts on the threads:


In practice, I mounted up the tire assembly to the drum, let it spin til the heavy side was down and then would move it 90° one way and add weight on the light side until it wouldn't spontaneously spin with gravity. I would then check that it remains static through 360° and adjust accordingly and I had figured this to be good enough to address any major imbalances. The weight I had to apply ranged from ZERO(!!!!) on one assembly to 3.6 pounds, most of them being in the 1-2 pound range. I then used some adhesive to secure the slab of lead to the inner surface of the wheel.

The left rear wheel about to be reinstalled, 2.25# of lead on board:


Despite all this work, I still get to mid-50's mph and there is a pronounced vibration which feels like it's gotten better below that but seems like it's gotten worse once I get there. It almost feels like one of the tires is severely out of round but the shimmy also fades in and out as I progress through bends, which makes me feel like it's phasing in and out with other tires. If it was an out-of-round unit, it wouldn't matter what the speed- it would always be lumpy and I should always feel it.

Speaking of which, while I had them on the balancer, I started checking how concentric the wheels/tires were but managed to forget to do it after the 2nd tire. I was very disappointed when I realized I forgot to keep checking this and I intend to pull them off and check them sometime during the remainder of this week. I anxiously await seeing where that leads me.

If anyone has any suggestions of how to better address the shimmy issue, I am all ears. If I am missing something in my balancing procedure, please point it out to me. I certainly don't feel like an expert but am willing to try anything to knock this out. Thanks in advance!
You are going to get beat to death by the rear tires with no weight on it. My tractor will bounce and feel like an out of round or flat spotted tire running 70 empty. With 24,000lb on the drive axles they ride great. The rear springs on a 1088 are designed for 44k weight. You have probably 8000lbs on those rear axles if that.
 
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CARMAN

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Bent axle? Maybe stick a gopro on the side of the truck. See if you can take a video of the wobble?
 
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Seattle Wa
First off I am still looking for my LMTV so I am a backseat driver at this point but I have researched tire balancing on these. What I am planning to do is use the balancing beads and put them in the tires.... Based on size of the tire there is a certain # that goes in each...
Like this:

!

Maybe this avenue will solve the vibration if it is truly the tires?
 

simp5782

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First off I am still looking for my LMTV so I am a backseat driver at this point but I have researched tire balancing on these. What I am planning to do is use the balancing beads and put them in the tires.... Based on size of the tire there is a certain # that goes in each...
Like this:

!

Maybe this avenue will solve the vibration if it is truly the tires?
It helps on a loaded truck. I have them in my tires. 14 to 16oz for a 395 tire. Fluid or beads. Beads are available at napa
The OP has an unloaded rear so its gonna shake and bounce
 

ckouba

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I guess I am pretty unloaded. Just went past a DOT scale:

Front - 9,800#
Rear - 7,200#

Total - 17,000

That is with me (~200#) and ~5/8 tank of fuel (30-ish gal).

I checked how round the tires are and the left two rear tires were a bit out of round, enough so that I may disassemble and remount to see if they improve. I drove around a bit with the CTIS in sand mode as well, and then re-inflated with the thought that any residual set the tires have from sitting around stationary would be flexed out a bit. This may have actually worked- at least it seems to have made the mid-50's to mid-60's much smoother. There is a range in the mid-30's to 40's where it still shakes quite a bit. Sounds like I need to get on with the build of the camper.
 

Bill Nutting

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If I could offer one word of advise. Be careful how much weight you add to this truck. I’ve seen these campers built too heavy and the rear end sags. Use as many light weight materials as possible. When I built out my M934, I removed about 2,500 lbs of stuff (all the expansible parts). After adding the RV mods the truck weighs about 41 k. I’m right at the limit. My truck doesn’t sag but I wouldn’t add any more weight either.83F52E34-3EAA-4288-B759-51AB97EBD7C0.jpeg
 

Bill Nutting

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When I bought my truck it had been sitting for eight years. It had 5,000 miles on it. All ten radial tires had flat spots. I tried to use inflation changes and drove it around for a year. It shook so bad, it would almost take the wheel out of my hands at 45 mph. It would be tolerable above 50 mph.
I had to replace all ten tires! The shame of it was, the tires it came with still looked new. No dry rot, lots of tread.
 

AllenF

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I have heard that there are take offs that were spare tires and never saw the ground. they are like new but they sat in the tire lift in one spot which caused them to have a built in flat spot. Once mounted and used on the ground they are out of round and vibrate badly. Could your new tires be from a source of spare tires? If so I am not sure they can be fixed. I am new to these beasts and so my info is at best antidotal.
Given the cost of these tires and the potential issues, I am thinking that a brand new tire from a tire shop and not a government auction and similar site would be better. The government pays just under $600 ea for these tires. They sit in a warehouse and at some point are dumped into the auction process. Good ones seem to go for around $400 and up PLUS shipping. This means they are closer to $600 ea. I have found a tire dealer that has many warehouses around the country. They are asking under $800 ea. I know it is more money but I am pretty sure these are brand new and not new old stock. As such you would be getting fresh tires and hopefully no sitting issues. I also think there might be a way to group buy and get the price down some perhaps a lot. Since they have warehouses around the country this might make it easier to go and get your own without huge shipping cost.
Just a thought. For me tires are about the last thing I will do so I am in no hurry.
Sorry for the hijack, but something to think about.
 
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