So the MTVR adventure begins

[aw113sgte]

Changed all the diff fluids today, front one had a sliver but looks like its a piece of the NPT threads on the fill/drain. Middle may have had a tinyyyy bit of water but scoping the diff internals showed no rust.
Got the new batteries and the wallet is hurting (6-700 a piece) from the AGMs but with my experience with flooded lead acid in my MTV I wanted the increased CCA of AGM (although the C12 starts way faster than the C7 so maybe it wouldn't be an issue.)

Touched a plug on the ABS module (or maybe TC) and it just crumbled like a dried out cookie. I assume every other connector is the same. Nice thing is, they are just seals so the pins can still be connected.


Found 2 ball joint seals that are cracked. Not looking forward to that as the replacement process is very involved.
The big surprise....Saw a castle nut backed off on the "tie rod". The taper was also loose. Had this nut fallen off, the rear wheel would have turned violently to left or right. Glad I caught it. Looks like when a service was done, the nut wasn't tightened and as such the cotter pin wasn't installed.

 

[aw113sgte]

Have been doing a lot of boring stuff lately, pulling stock heater for future AC install, lining floor with vibration damping (the good, pricey stuff from resonix). Got the floormatt material from the same supplier to the military (supposedly-it does match the floor matt of my MTV). Installed the keyed door handles. Put on the sides and cover to let the kids at my sons school play around in it. (The stock 12v converter powered the fridge filled with ice cream without issue).

 

[aw113sgte]

Original heater panel was in bad shape, cracked. I also didn't get a new panel in my AC kit and they seem to be unobtainable on their own. 3D printed a new one with transparent letters so the LED backlight would still work - although it doesn't end up lighting it very well. Old fan switch was a bit rough so replaced that as well, and put in a switch for the future AC install.


Few pictures of the mounting methods for the new seats. The aluminum bar on the rear bulkhead is tied into the truck with 8 bolts across it's length. Each seat has 4 bolts. The seat bottoms fold down and can rest on the storage box. The drivers seat had to be moved over a few inches to fit the 4 across.

 

[aw113sgte]

If you have a failed fuel sender, this one works. It doesn't have the low fuel light capability but other than that, good to go. You do have to wire it in. Isspro, part number RA9521-ISS-LP, $114

Connect to red and black wires. Blue is for the low fuel light. Sender wires are non polarized so you can connect either way.

You do have to slide the tank out to remove the sender.

FYI, I did check for the original part number but the manufacturers won't sell it and ATAP requires an order of 5 with a long wait time. Isspro used to make the OEM ones but no longer do.

 

[aw113sgte]

Haven't spent a ton of time on the truck lately with the kids being out of school for the summer and going on lots of trips with the FMTV camper. Did get the cab taken apart a bit to get all the needed measurements and have modeled up the design a little. Going with a cabover setup, with an accordion seal to the rear habitat. With the cab roof and rear panel gone, there will be a large pass through area. Planning on putting 2 beds in the cab over. That structure will be mounted to the turret legs (that will be cut down a bit). The turret legs will be braced even more to help with rollover protection. I am currently thinking of building the cabover to be a self contained "survival pod". If I built it strong enough to support the truck in a rollover it would make it way too top heavy - like 4"x4"x0.25" steel members (making a rollover more likely). So instead the frame will be tubular steel (thinking 2"x2"x0.1" but that may change a little) and have breakaway bolts so it separates in the even of enough load. Will have 6 point belt system for the beds.





I think I will be removing the front bed bulkhead for more room. The exhaust stack will be a bit shorter and I'll have it exhaust sideways - out and away from the habitat. The air intake will also be shortened (I have the cap attached directly to the filter inlet for now). I do need to have the space between the cab rear wall and the habitat enough so I can shimmy back there to service the vents and valves. I may move the transmission fill location. I suppose I could move all the stuff back there if needed.

 

[aw113sgte]

Finally got around to adding some sun and rain protection of the firewall components.

 

[BKubu]

Finally got around to adding some sun and rain protection of the firewall components.
View attachment 951203View attachment 951204

You should patent and sell that!

 

[aw113sgte]

You should patent and sell that!

Lol, sheet plastic, a jigsaw, circular saw and 30 minutes.

 

[aw113sgte]

Installed JW Speaker LED headlamps. If anyone else is looking, the connectors are Metripack size 280.



Got a couple wheels from Feltz Tire. Highly recommended. $50 per wheel, $25 per beadlock.


Playing in the woods a bit and testing how she does with lockers engaged.
"Her visual acuity is based on movement, she can't see you if you don't move"

 

[aw113sgte]

Been quite a while since updating. Few items of progress, planning on making the entry door low so don't need to deploy and stairs to get inside. A section of the bed will need to be cut out to do this. Right and left slide outs will be different lengths, this will give a way to get into the habitat when slides are in. A large passthough is present, a couple beds above the cab. Other beds will be in the back.

Planning on 2x2" 6061-t6 square tube for most of the frame. Will be connecting it all with Huck BOM system. XVENTURE Off-Road Camping and Utility Trailers - YouTube These are basically really heavy duty structural rivets. I didn't want to weld aluminum and deal with the temper loss and them propensity to crack. Steel was an option but then the rust and weight concerns come into play. There is still a ton of design work needed, this is more of the general layout stage.




Slides will be gear driven, pretty similar to the m1087 setup. I considered the various methods out there but this looks like the most robust that isn't going to get hurt with offroad dynamics. All the RV slide systems are pretty fragile. Gears are steel, module 6 (about 1/2" gear pitch). Driven with a single stepper motor per slide though 50:1 reduction planetary gear sets. Having all the gears mechanically linked keeps everything in line so there is only an initial adjustment.



Went through a lot of thought for the exterior. Ended up deciding on Coosa fiberglass reinforced polyurethane foam. It's commonly used in boat building. Has a decent insulation value, is very good against impacts, easy to repair, easy to bond with polyurethane sealants. Also looked at ballistic fiberglass panels, aluminum sheet (diamond and smooth), and steel. With the Coosa I can avoid the spray foam which will allow a lot more freedom for wiring access, repairs, easier to tie into the framing for structural seat supports (that can handle crash forces).


Made a trailer hitch, 1/2 steel laser cut. Requires 4 new holes drilled in the brace.






Got the turret legs modified. By chopping off the tops and putting a new mounting plate I can have the overhead cab space larger. Also cut off the section that holds the led lights about the windshield, this allowed for an extra ~2" drop. You can see the bar going across, about 1/8" clearance for sealant fill.
Yes, I skipped leg day.



Working on replacing the boots on the suspension a-arms, also taking care of the boots and seals while I'm in there. Pretty decent job that required making some custom press tools to get the boots properly seated. Usually I can get away without having one, but these are in a tricky spot and pretty delicate.


Lots of creative methods needed to separate the joints.



Press tool:


Engine hoist to support the 500lbs of suspension. You can see the sleeve pulled out of the knuckle and stated with the joint (this is only on the lower joint). A little heat and a hammer popped it off fairly easily.

 

[MAdams]

Where did you get the insulating mat for the floor?

 

[aw113sgte]

Where did you get the insulating mat for the floor?

Floormats

Our acoustical floormats stop noise from penetrating floors and firewalls. All rolls come 54" wide (4 1/2 '). Custom lengths upon request. We usually ship within 3-5 business days by FedEx or UPS. Floormats come in four colors and can be hosed off repeatedly. Installed Diamond Plate...

cabinsulation.com

It's nice stuff, easy to work with, pretty sure its the same stuff that's came in my FMTV.

 

[aw113sgte]

Finally got above 10f so started work on the next axle with a ripped boot. Balljoints in great shape, no noticable play. A lot faster now that I've done one axle. Getting axle seal out is still a pain, I don't have the hub end apart so can't punch it out from the other side.
Separating the tie rods without damage, best method seems to be taking an air hammer to the side of the nuts.

Also, if you're looking for identical castle nuts, found them here: https://belmetric.com/castle-nut-low-17h-carbon-steel-plain-din-937/?

Got all the seals from ATAP, this enough for entire truck axle, hub, CTIS seals.

The huge ball joint boots:

 

[aw113sgte]

Moved all CAD work to Onshape from Solidworks. Benefit is anyone can look at the model.

Link: https://cad.onshape.com/documents/6...renderMode=0&uiState=69974878de0efba4416291a0



Decided to drop the rack and pinion system for the slides for a custom cable driven system. Lighter weight, more adaptable, easier to seal, less expensive. Components are at least double the strength (torque, cable diameter, gearbox) that commercial units. Here you can see the motor/gearbox/sprockets, corner pulley assemblies.



A lot of current work has been going towards the battery system. These are used LTO (Lithium Titanate oxide) Toshiba batteries. Basically they are industrial batteries that have a bit lower energy density compared to LiFePO4, however they have a hugely long lifespan, can charge in 8 min to 80%, don't loose power in the cold, can be charged in the cold - no reason for heaters at all.


They come with a BMS but no one had figured out how to talk to it with available hardware. These are only sold to industry and you can't just buy the battery management unit, and even if you do, it has all sort of requirements for contractors, current sensors, etc else it will shut the packs down.


After a lot of reading manuals, sniffing data I eventually got a solution and can use the built in balancing board (CMU - cell management unit)


ESP32 based microcontroller module. Can read all cell voltages, temps, enable cell balancing. Thebatteries are connected together over CAN with ethernet cable,


Each pack is rated for 1104 kWh, initial testing shows above that at 1115 kWh