Project AWOL: 1986 CUCV M1010 Ambulance

[jamesgrizzlyadams]

Updates, More to Follow

Here are a few quick photos of some of the recent work I've done... I'll take some more photos this weekend and post up some details. Lots more work has been done, these are just the photos I have on my iPhone.

Happy to say the Ambulance is now starting reliably (even on cold mornings), runs well, and the batteries hold a charge!

I changed the fluid in the differentials... fairly simple task. Hardest part was removing all the old gasket. It also proved to be a bit interesting getting the new gear oil in through the fill port: I was using a crappy little pump and it exploded on me, leaving me literally covered in gear oil. Fun stuff.


Front and Rear Differentials


Differential covers being cleaned, and gasket maker.

While I was down there I started the install on my ARB Differential Breather kit... Installed the manifold where the DUVAC used to be... more details to follow. Breather lines are in place for the two differentials, the transfer case and the transmission. Just have to make the final connections and tidy them up.


This is the ARB manifold and air filter, installed on the plate where the DUVAC used to be mounted.

I replaced the stock fuel filter assembly as the fuel filter base was leaking diesel. This would mean air in my fuel lines, and mean that I had to prime the fuel lines every time I tried to start the truck after it had been sitting overnight. The truck would roar to life (fuel in the injector lines, downstream of the injector pump) then die off within a few seconds. I'd then have to crank it a whole bunch to prime the lines before it would start, not ideal. Only fuel filter I could find for now was a CAT filter... I'd like to run the RACOR filter like stevo-mt did, and many others that I've seen online, but it's a pricey setup. The new spin-on fuel filter and lines seem to have solved the starting issues, it now starts up right away and seems to idle a lot smoother too.



I had to make a little jimmy-rigged mounting plate for the filter housing, to keep the filter clear of the wiring on the firewall and clear of the engine components.. I'll try to build a more robust mount soon.

Took her out for a little trail test, ripped off my cb antenna about 50 ft into the trail haha. Live and learn I guess... The truck handled really well, and even made it down a small off-kilter rock descent, then back up. Not bad for 30 yr old bald tires at road pressure.

 

[Hartigan]

... Hardest part was removing all the old gasket...

I pulled the covers off my M1010 a couple weekends ago to inspect and change fluid, and I'd say it took me 3x as long to scrape all the old factory gasket material off the housing and the cover than to do the rest of the job. Crazy. I'm not sure what they used originally, but it definitely doesn't want to come off easy!

I had a set of brass scrapers that helped to pull the material up without scratching the sealing surface... If you ever come across any, get them! It's a super handy tool.

The ARB setup seems really cool! I hadn't thought about running the breathers up... I'll have to add it to my list!

 

[jamesgrizzlyadams]

Inaugural Overnighter

So I had the first official overnight trip in the M1010 this past long weekend. Just took it onto a chunk of crown land not too far from my place, within a reasonable rescue distance if I had to make "the call". The truck performed flawlessly and I was pretty impressed with it's performance on the trail leading in. This thing has a lot of pull down low, in 4low I basically just had to cover the brakes as it crept up rocky ascents at idle.





I got the side and rear spotlights wired up, they really make getting to and setting up camp in the dark a lot easier. The photo really doesn't do it justice, but you can go about your business all around the truck without having to use a headlamp or flashlight. It also helped on the way in to keep an eye on rocks and logs close to the side of the truck on the trail.

I also replaced the headlights with some newer Sylvania Silverstar H6054 lights (pretty cheap at around 60$ for the pair), and have ordered the LMC heavy duty headlight wiring kit (30$), to provide them with a better power source straight from the battery. The stock wiring configuration for the headlights is a little bit ridiculous which I think contributes to how dim the lights are.


It's still painfully slow and loud, and really isn't suited for roads with a speed limit above 80km/h(50mph) in its current configuration, it's just screaming at that speed with the stock wheel size and gearing. I think my next big ticket item will be to get some new, bigger wheels on there. I'm going to take stevo-mt's advice and hold off on the lift as long as I can, I'll try to fit 35's with some fender trimming and no lift (for now).

I'm thinking these rims: 17" Pro Comp Steel Wheels: 8 bolt on 6.5", 4.25" backspacing. These rims have roughly the same backspacing as the stock ones and should give me the best fit.. anyone else out there with a CUCV and bigger rims/wheels?

 

[bknudtsen]

One word of caution regarding aftermarket steel wheels; make sure their weight rating is sufficient for you rig. Most I have seen only have a 2000lbs rating vs. a 3400lbs rating on similar sized aluminum.

 

[jamesgrizzlyadams]

One word of caution regarding aftermarket steel wheels; make sure their weight rating is sufficient for you rig. Most I have seen only have a 2000lbs rating vs. a 3400lbs rating on similar sized aluminum.

That's a good point, and I was a little bit wary of that after researching rims online. The Pro Comp rims have a few different "series" of steel rims that would fit, some say max load 2000lbs, some don't list the max load.
Those rims on your 2500 look pretty slick... maybe something like that would be a better choice. Something like this... Looking at it, it looks like you're right, as the max load on the comparable alloy wheel is ~3400lbs.

I'd like to just use the stock rims, but at 6.5" wide they're too narrow for a modern larger diameter tire (i.e. 315/75/R16, 35x12.5x16). I don't really want to squeeze a tire that has a recommended minimum rim width of 8" onto a 6.5" rim.... right? It seems like the only way I can get a larger diameter tire with the existing rims is if I use a tall and narrow military tire like the Michelin XL's (9.00R16), which are expensive and certainly not as easy to get.

 

[jamesgrizzlyadams]

Another successful overnight trip this weekend... Every trip I take it on adds to my project to-do list as I figure out little tweaks I want to make.

I'll post some progress updates this weekend. For now here's my panel wired up, but not mounted. The "engine instruments" and "depth sounders" are for my glow plugs... doing my best with marine labels haha.

 

[jamesgrizzlyadams]

12V Power Distribution

I decided the 12V power distribution under the hood needed to be cleaned up, so after installing the new 12V alternator I stripped all the old stuff out and started from scratch.



Left: My new 12V distribution post to replace the old and undersized one on the firewall. It's a 150A 3/8" "Power Post" from Blue Sea.

Middle: After removing the glow-plug resistor, the glow-plugs still weren't firing, so I got a new ST85 relay.

Right: Two circuit breakers from BlueSea... One will protect the 12V powerpost on the firewall and the other will protect the camper battery bank, which will also be separated from the 12V distribution/alternator by a Sure Power battery separator. These are pretty nice as they can also be used as a sort of "killswitch". If I'm going to be leaving the truck for a few days I can just pop the hood and disconnect the breaker, to prevent potential drain on the batteries or theft (if someone really wants to steal this moneypit of a project). Despite the fact that the starter is 24V, the starter relay needs a 12V signal from the ignition so it won't start with the 12V circuit breaker open.



Left: Existing 24V distribution bar, I labelled it to avoid any confusion.
Right: The new 12V panel roughed in with the two circuit breakers and a BlueSea 600A powerbar. I will be connecting extra lights, winch and any other high amp draw 12V accessories to this bus bar in the future.



The new 12V distribution panel is mounted under the hood at the front passenger side, right next to the 12V battery and alternator, The bus bar is fed from the positive terminal of my front battery (12V), which is where the new alternator is connected to as well. The breaker up top feeds into the SurePower battery separator, then to my battery box in the camper (where I've got my inverter installed, and reading 14V when the truck is running). The battery separator is also wired up to the start signal at the starter relay. When I go to start the truck, if the battery under the hood has a low voltage, it will boost the battery under the hood with my camper battery. The lower circuit breaker on the panel feeds the 12V "powerpost" on the firewall which feeds all the trucks 12V electronics as well as the new glow plug relay.



Left: Battery box in the camper with inverter.
Right: 12V Powerpost and glow plug relay on firewall.

With the new 12V distribution and glow plug relay, the glow plugs are working again.

 

[jamesgrizzlyadams]

Heater Core

The old rotten heater core under the dash was leaking coolant into the passenger side foot well. I replaced the heater core and the associated hoses before draining, flushing and refilling the coolant. I also used some adhesive type insulation on the firewall behind where the heater box is mounted.



Heat works beautifully and I'm no longer leaking coolant. When I bought the truck there was a mouse nest in the coolant overflow bottle so that obviously got taken off and all cleaned out before flushing the system pretty throughly (did two passes with rad flushing solution then a couple more passes with water before draining and refilling it).

I installed a fire extinguisher on the camper door too. Safety First.



These photos are from early this spring, we don't have that much snow yet up here in Canada! Still catching up with updates.

 

[DT75FLH]

That's a good point, and I was a little bit wary of that after researching rims online. The Pro Comp rims have a few different "series" of steel rims that would fit, some say max load 2000lbs, some don't list the max load.
Those rims on your 2500 look pretty slick... maybe something like that would be a better choice. Something like this... Looking at it, it looks like you're right, as the max load on the comparable alloy wheel is ~3400lbs.

I'd like to just use the stock rims, but at 6.5" wide they're too narrow for a modern larger diameter tire (i.e. 315/75/R16, 35x12.5x16). I don't really want to squeeze a tire that has a recommended minimum rim width of 8" onto a 6.5" rim.... right? It seems like the only way I can get a larger diameter tire with the existing rims is if I use a tall and narrow military tire like the Michelin XL's (9.00R16), which are expensive and certainly not as easy to get.

a 255/85/16 would fit on the 6.5 wide rim and give you basiclly a 33x10.50x16 tire...but it only changes your gearing about 100-200 rpm as its only 33" tall. should fit with no lift.

also check your crank pulley for wear around the rubber ring. as it fails the crank harmonics WILL crack the crank in 2. I had a suburban that it happened to and is a know issue with the 6.2...mine lasted 300k though ....but with the low miles and decent humidity yours should last pretty long.

 

[jamesgrizzlyadams]

a 255/85/16 would fit on the 6.5 wide rim and give you basiclly a 33x10.50x16 tire...but it only changes your gearing about 100-200 rpm as its only 33" tall. should fit with no lift.

I took a good look at running the 255/85/r16 tires... I had almost decided on buying a set of BF Goodrich Mud Terrain KM2's in that size but decided to stick with my plan of buying new 17" wheels. Although it seems like most 16" tires are cheaper than the comparable 17" version, there are a a lot more options for the 17" wheel (especially in the 37x12.5 size, which is where I'd like to end up). I'd also need to buy new 16" rims anyways, if I wanted to go any bigger than 33", as the stock rims are too narrow for a 35x12.5 for example.

SOO.... I ordered some new 17"x9" alloy rims (the procomp ones from 4wheelparts), rated to 3400lbs, just waiting for them to arrive and I will test fit the 35's, should give me about an 8km/h increase in top speed. More importantly I can get rid of the old, cracked, bald 31" tires that are on there now. The 17" rims should give me lots of options for easily available tires in the future (also the same size as my silverado).

also check your crank pulley for wear around the rubber ring. as it fails the crank harmonics WILL crack the crank in 2. I had a suburban that it happened to and is a know issue with the 6.2...mine lasted 300k though ....but with the low miles and decent humidity yours should last pretty long.

thanks for the heads up, I had heard about this issue before but haven't looked into it. I'll have to add it to the list.

 

[stevo-mt]

I should probably do something like your fire extinguisher on the back door. I've been keeping mine in the side compartment where the old heater was. Other than the paint and other stuff inside the aluminum body does make me feel a bit more safe when it comes to fire danger. I've seen a regular camper catch on fire and it went quick.

Truck is looking great!

 

[chilliwak]

Big time:Wow1: upgrades James. There is some nice work:drool: you have done there. If you do ever go with some suspension changes I would recomend the 2 inch lift front springs from BDS. They have a military meening that the second leaf wraps around the main leaf so that you can break your main leaf and still be able to drive. The BDS springs also get rid of that negative arc that you have in the stock springs. Check out my buld thread in my sig to see how it worked. I am running 37s without too much fender triming. Cheers, Chilli..

 

[mr_ed]

Really digging your build man! I keep planning on stepping up in a couple years, and I keep flip-flopping from a converted civilian van-body ambulance to a m1010 and back again...builds like yours really make me want to go the m1010 route.

Great job!

Ed

 

[jamesgrizzlyadams]

Really digging your build man! I keep planning on stepping up in a couple years, and I keep flip-flopping from a converted civilian van-body ambulance to a m1010 and back again...builds like yours really make me want to go the m1010 route.

Great job!

Ed

If you can find an M1010 in decent condition I would highly recommend it. It's been an awesome rig and has been relatively easy to work on, even for a newbie like myself. It's also a very stout, "over axle'd", truck.

I've been posting more regular updates on Instagram as it's a bit easier (I can just do it from my phone). I'll try to catch up with some photos on here.
For those that have instagram, you can check out my build updates there too.
My Instagram for the build: @rolling.thunder.cucv

 

[stevo-mt]

Any plans on a heater replacement for the rear?