M1010 Ambulance to Expedition Rig

Outback

Explorer
I have been gone on another 4 month deployment. When I returned I found another pack rat had taken up residence in my engine compartment. Time to get out the anti freeze. He refuses to eat any of my poison or go near my rat trap. smart little bastard. His days are numbered.

Truck runs well. Need to clean out his nest after I kill him so I don't set what ever he has in it on fire. Had a friend who started up his snowcat after a long time sitting next to his house. He came back to the cat in flames! Turned out to have been a rodent nest on his manifold that caught on fire.
 

arveetek

Adventurer
I will also change my gear ratios from 4.56 to 3.73. A built 700R4 will be installed as well as a NP205 T case with a Magnum Box added.


May I ask why you want to change the gears, especially with a 700R4 in the future? I think you will greatly regret doing that. I had a built '81 C20 with a turbocharged 6.2L, 4.10 gears, 700R4, and 31" tires. That was a really sweet combo. The steep overdrive of the 700R4 is a perfect match for the lower gears. I would keep the 4.56 gears and go with larger tires. Then you'll have a perfect combo for off-road and highway driving.

My current diesel is the 6.5L with 4L80E, 3.42 gears, and 33" tires. The 4L80E doesn't have as tall of overdrive as the 700R4, but I wish I had lower gears. Overdrive is fine for highway driving, but if I try to tow my 18' travel trailer, I have to shift into 3rd.

Most guys that build these rigs desire the 4.56 gears. So my suggestion is keep them! :D

Casey
 

Outback

Explorer
I must say thank you everyone for the support and advice. I will post some pics from Mondays quick trip to the national forest next to me. The wife loves the Campulance. So far the Pack Rat has won each battle (kinda). He insists upon moving into my engine compartment. I keep removing his nest and he keeps repacking it back in. Its kinda comical at this point. He has escaped death twice now from my rat trap (looks like a over sized mouse trap. The bait is part of his nesting material since he refuses to eat what ever I put in the trap. Peanut butter, fruit, mouse bait (green gooey stuff) etc etc etc. Even tried cream cheese. But he sure goes for his soft bedding material. Third times a charm they say, we shall see.
 

Outback

Explorer
OK onto the fun stuff! My plan was to try and keep the lift low as possible but have good suspension travel. I need ground clearance for sure but also need good highway manners. No matter what you do there will always be compromises. So I have come to the following conclusion. ******K it!

Ultimately I want to be able to go places I really want to go to. So I need ground clearance. This calls for a lift and taller tires. I need to be able to travel at highway speeds. This should be around 70 (most of the Country). That calls for more power and an overdrive transmission. I need creepy crawly gears for technical terrain. Again gearing comes into play. So here is what I have come up with.

Ground Clearance: 4" Off Road Designs lift with all the bells and whistles. This also includes a set of King shocks and steering stabilizer. 37x12.50 BFG Baja Mts Mil Spec on a set of Trail Worthy custom internal dual bead lock wheels. (picture shows a 6 lug pattern mine will be 8 lug 8x6.5 pattern)
 

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Outback

Explorer
Transmission: Lets start off with the stock Turbo 400 Trans. Excellent trans but has NO OVERDRIVE. First gear ratio is 2.48 with a final drive ratio of 1.0. Now lets look at Overdrive transmissions. The king for "stock" OD Chevy trans would be a 4L80. Has a 2.48 1st gear with an Over Drive gear of .75 25% OD not bad. Draw backs are its Computer controlled or Electronically controlled. So thats an additional $1200 dollars for a stand alone electronic controller. Plus when I do the math the OD is just not high enough for what I want. Next in line is the 700R4. In stock form not really strong enough. BUT as with many thing there are very talented professionals that build a 700R4 the is more than capable of handling the weight of my vehicle fully load and then some by a large margin and more than capable of handling over 700 hp and high torque. First gear ratio of 3.06 (impressive and great for off road plus getting a heavy vehicle going) and an over drive gear of .70 Again impressive and meets my highway speeds. Plus its not Electronically controlled! PATC makes the best 700R4 out there and they are unbelievably strong! So the purpose built 700R4 will be my choice.

Here are the highway RPMs with the tire and OD Trans combo I have chosen: 70 MPH = 2056 RPMs (4.56 axle gears, 36.5" tires, .70 OD Ratio)
 

Outback

Explorer
Transfercase: The stock NP208 is a good transfercase for sure. Drawbacks are its an aluminum case, chain driven and suffers from stretched chains and or cracked case when used off road with higher demands called upon it. Gear ratios are 1.00:1 High Range with a decent 2.61:1 Low Range.

The NP205 is Legendary in its cast iron case strength and bullet proof gear driven guts. The draw back is it measly Low Range of 1.96:1. But strength wins this battle for me because there are another group of professionals out there that more than make up the difference of it measly 1.96 Low Range.

Off Road Designs Magnum Box is a planetary gear reduction box that bolts to the front of an NP205 transfer case. This transforms the NP205 from a strong transfer case with mediocre low range gearing to an extremely strong transfer case with four range options giving you all the low range you could ever want.

Transfercase ratios---NP205 range----Magnum underdrive range
1.00:1---------------------Hi-----------------------Hi
1.96:1--------------------Low----------------------Hi
2.72:1---------------------Hi----------------------Low
5.33:1--------------------Low---------------------Low

Creepy Crawl ratio achieved! With the magnum box in Low Range and the NP205 in low range you get a 74 crawl ratio! Note here that automatic transmissions offer the benefit of gearing built into the fluid drive torque converter. One can multiply an automatic transmission's low gear by a factor of 1.5 to 2. So that gives you a crawl Ratio of 112 down to 149! Thats very impressive! The great thing is you also have 2 more low range settings of 1.96 and 2.72. Low Ranges and Hi Range for any terrain.
 
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Outback

Explorer
Ground clearance: As said before ground clearance comes from a combination of lift and tire size. The taller the tire the higher the diffs are off the ground. Also this gives you more break over clearance. A suspension lift does nothing for diff clearance but helps with break over clearance. So a combo of the two is needed. On the 14 bolt rear diff there is one thing you can do to get higher ground clearance. Well 2 things but one is not very practical. Add Portals and or shave the diff. Bolt on portals are not good on a rig that will see highway speeds. So those are ruled out. But shaving the bottom off of the 14 Bolt gets you more clearance than a Dana 44! So I will shave the bottom off of the Corp 14 Bolt. Its more complicated than that but you can watch Youtube videos on how to do it. Not hard just time and labor to do.
 

Outback

Explorer
More Power: For more power I have decided to go with the proven Banks Sidewinder Turbo charger. Being this is a Military vehicle let alone a M1010 ambulance the install its not as straight forward as with a Civilian K30 Diesel. Banks claims +60 hp and +115 lb-ft (rear wheel) plus 19% more MPG. From experience I believe they are pretty close to those numbers. It really wakes up the 6.2 diesel and you do get better mileage.
 

stevo-mt

Member
More Power: For more power I have decided to go with the proven Banks Sidewinder Turbo charger. Being this is a Military vehicle let alone a M1010 ambulance the install its not as straight forward as with a Civilian K30 Diesel. Banks claims +60 hp and +115 lb-ft (rear wheel) plus 19% more MPG. From experience I believe they are pretty close to those numbers. It really wakes up the 6.2 diesel and you do get better mileage.
I'm on the same boat. I found a used banks kit for like 400$ without exhaust, but I'm going to just buy the new one after hearing some horror stories...

When you lift it you will have to tweak the stock exhaust anyways so what better time than to install the turbo!

I have to redo my battery mounting and some of the electrical work to fit the turbo in. I'll finally get to do that project in February, so which one gets started first gets to post pics! My biggest regret is doing any other work before the turbo install...



Sent from my SM-G900V using Tapatalk
 

chilliwak

Expedition Leader
Cool pics posted there Outback. Me like:drool: Good to see you posting here again Stevo. I always like to follow your adventures. Cheers, Chilli....:)
 

Outback

Explorer
Looks like you will get first shot at posting pics on the Turbo install. I will be back out in the field next week until Christmas then gone again until February or so. I will be watching your thread!
 

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