M920 - Passenger tank install, battery and air tank relocation

[Hammer]

M920 - Passenger tank install, battery and air tank relocation?

Ok, I picked up another fuel tank with brackets to install on the passenger side of my M920.
I obviously need to relocate the batteries, air tank(s) and move the exhaust back some.
I was planning on keeping one air tank about the fuel tank, like on the driver's side, but I am rethinking that some due to the cramped space and if I leave that area open, I will have a 'little' more access to the air lines, etc. that run to the top of the transmission.
The air tank under the driver side really blocks a lot of access!
I was thinking about moving the air tanks up to the side of the winch setup and plumb them vertical.
I don't really want to put the batteries in the cab under the passenger seat. But that would be the EASY solution.
I am not really wanting to put the batteries into a hard to reach area, but this might have to be the answer to move everything for the extra fuel tank.

I know Soni mounted an extra tank on his truck, but I don't see any details.

 

[155mm]

Freightliner Columbia trucks have the batteries between the frame rails behind the cab/sleeper, might make the battery cable run a bit farther, but they would be out of the way and not in the cab.



The only hiccup might be the big ol cross member that might be in the way

 

[155mm]

Just looking at the photo of the batteries again, you might be able to turn that battery box 90* and put the driveshaft hump over the cross member

 

[Hammer]

I have to also watch all the stuff for my lift axle on the 920 as well.

 

[155mm]

I remembered the tires in the way, forgot about the lift... back to the ol drawerring board

 

[Hammer]

Btw, I pull off the stock 5th wheel, cut the ramps shorter and mounted one from my 818 further back.
So I do have some room I could put stuff right behind the winch on the cat walk. Or maybe lower them down 'some'. But that is right where all the lift axle stuff is at. But I could put the batteries there if need be.
Still need to move the air tanks though. And I don't know how they will drain right if I mount them vertical.
5 air tanks start getting hard to find places for that are out of the way!

 

[simp5782]

tank. ked up a battery box from a mack CXN613 truck. Will hold 2 group 31s. Or one 8D battery They are 14in wide. 21in from the frame. An air tank can be mounted to it.

I am going to mount it under my winch platform on the frame.

On the 920 two of these could be mounted to the winch frame base like I did my spare fuel tank.

I am going to add a big tank to the passengers side as well.

 

[Hammer]

tank. ked up a battery box from a mack CXN613 truck. Will hold 2 group 31s. Or one 8D battery They are 14in wide. 21in from the frame. An air tank can be mounted to it.

I am going to mount it under my winch platform on the frame.

On the 920 two of these could be mounted to the winch frame base like I did my spare fuel tank.

I am going to add a big tank to the passengers side as well.

I was looking at adding something there, but I would need to put the tank on, and figure out the routing on the exhaust as well.
The drop axle and all 5 air tanks make this a more difficult job on the 920 compared to the 915 and 916. But I know it can be done.
I am also thinking about just putting two group 31's rearward of the winch platform, about half submerged. I figure I can push the catwalks back a foot, and drop the batteries down some to keep them from being too exposed, but still within reason of being accessible.

 

[US6x4]

I know Soni mounted an extra tank on his truck, but I don't see any details.

Here is a walk around of the truck Soni built - might catch a peak of a useful detail or two...

 

[Hammer]

Here is a walk around of the truck Soni built - might catch a peak of a useful detail or two...

Yeah, that was about how I planned on routing the exhaust, and it should have room to put the batteries right off the side of the winch mount. Maybe an air tank on top of that as well.

 

[simp5782]

Other idea. I probably won't stick with this but I thought about making a box on top if the winch platform to stand on with batteries in it. Looks like a 939 battery box would work and have the folding lid. I mean standing up 15in higher isn't a big deal. Put rubber matting on the grate. Drill holes for battery hold down j hook bolts to lock in the grate

 

[simp5782]

Well as it lucks out. The fuel tank mounting straps and the battery box mount share the same bolt pattern. Minus the strap bolt hole. Can't believe someone was actually thinking on that one.

I will try to get this done this week. Exhaust should be pretty easy really. You have 3 inches on the passengers side that the tank can be more forward than the drivers side near the cab/engine bracing. The tank will stick out 6 inches past the rear of the cab then rather than the 9in on the the driver's side.

Will need a 5 inch flex pipe, two 5 inch u bolt clamps. And a 45 degree 5 in for the exhaust (or use a flex as well)

 

[Hammer]

Well as it lucks out. The fuel tank mounting straps and the battery box mount share the same bolt pattern. Minus the strap bolt hole. Can't believe someone was actually thinking on that one.

I will try to get this done this week. Exhaust should be pretty easy really. You have 3 inches on the passengers side that the tank can be more forward than the drivers side near the cab/engine bracing. The tank will stick out 6 inches past the rear of the cab then rather than the 9in on the the driver's side.

Will need a 5 inch flex pipe, two 5 inch u bolt clamps. And a 45 degree 5 in for the exhaust (or use a flex as well)

Thanks Wes!
I looked at but hadn't measured to see if the straps would interchange.
I was also thinking of moving the tank forward some as well. But I need to watch how the steps line up for climbing into the passenger side of the truck.
On my extra tank, they cut the strap bolts, so I need to get new ones for that. Maybe I can work around the missing hole while I do that.

I was thinking about running a larger stack on this truck. I love the sound of the 5" straight pipe, but my passengers are not as thrilled when I hit the jakes...

I have a second M920 that I am going to do this mod on, and I think it will be one of the first mods to the truck.

 

[simp5782]

Thanks Wes!
I looked at but hadn't measured to see if the straps would interchange.
I was also thinking of moving the tank forward some as well. But I need to watch how the steps line up for climbing into the passenger side of the truck.
On my extra tank, they cut the strap bolts, so I need to get new ones for that. Maybe I can work around the missing hole while I do that.

I was thinking about running a larger stack on this truck. I love the sound of the 5" straight pipe, but my passengers are not as thrilled when I hit the jakes...

I have a second M920 that I am going to do this mod on, and I think it will be one of the first mods to the truck.

If you can find a 915A1 tank it would be better. Some of them have the same tanks with the 2 steps. Some have the 6 step variants. Or find some that could be welded to the tank where you want them to be.

 

[simp5782]

Got these aluminum boxes from the @Swamp Donkey. They went to some MRAP storage kit. Decided to use them as battery boxes. two group 31s fit nicely with 3/4" rubber/fiberglass mat under it and on each end and in the middle. The engine side mat will be up even with the battery to deflect heat.

 

[Hammer]

Got these aluminum boxes from the @Swamp Donkey. They went to some MRAP storage kit. Decided to use them as battery boxes. two group 31s fit nicely with 3/4" rubber/fiberglass mat under it and on each end and in the middle. The engine side mat will be up even with the battery to deflect heat.

I like how this puts the batteries out of the way for most things, especially with a dual tank/winch/drop axle combo.
But they look like it would make working on that side of the motor a PITA.
Even pulling the batts still leaves that box to pull for better access.
Still, I will think on this, I am not that far off from doing mine.

 

[simp5782]

.

 

[simp5782]

916 and 920 trucks have a lot more room above the fuel tanks for their air tanks compared to the 915.

You can see the mounting line on the fender on top of the tank ve the dual air tanks mounting line on the passengers side fender. You may have to move one tank and recenter the other one on that bracket

 

[simp5782]

Done.

Had to drill 6 new frame holes. Only used 2 straps. One tank is mounted to the underside of the cab. Second is mounted inside the winch frame rail. Moved the exhaust back to the front of transfer case. Stack runs up and out even with the inner frame.

 

[silverstate55]

Looks awesome! That’s how the 920s should have been...