Simp's M915A1 Build Thread

[Hammer]

With that bigger filter in there, is there enough room between the filter and the canister to flow that much air now? Looks like it is in there pretty tight.
Otherwise, I really like the increase in filtration!

 

[simp5782]

Its got probably 2in between it and the filter. The stock housing has a lip that i cut out that blocks the direct intake of air and flows it around. I just removed that. I will add a second intake duct probably.

Hooked it a 53ft van trailer full of tires a few min ago. Egts dropped by nearly 200 degrees compared to towing it 2 days ago

 

[Hammer]

And there are the numbers that matter!
My filter is in pretty good working order, but I have to think an upgrade like this only makes perfect sense.
I will probably do it when I swap the turbo out.

 

[simp5782]

Did you want a hot shift pto ,I ordered a 221R air shift and direct pump mount. custom order still waiting for it .$1200 can.

The Allison HT700 series transmissions require a pressure lubed type PTO. Which your setup on a m939 series does not require.

 

[Glenngineer]

The Allison HT700 series transmissions require a pressure lubed type PTO. Which your setup on a m939 series does not require.

Sorry should have paid more attention to the model of truck you are working on ,that being said pressure lube is not required but is recommended on my PTO and mine was ordered with it. Thanks for the reply.

 

[simp5782]

Sorry should have paid more attention to the model of truck you are working on ,that being said pressure lube is not required but is recommended on my PTO and mine was ordered with it. Thanks for the reply.

The HT740 allisons are on top of the transmission at the 11 oclock position and pretty much a full blown MFer to put on since you have to pull the cab or pull the transmission.

 

[simp5782]

Swapped the 11R24s out for 395 MVTs for a few trips i gotta take. I had a decent offer for the 11R24s i had on it so yea sold those. I am acquiring some 12R24.5 casings and wheels. Just waiting to find enough to get em recapped.

Bypassed the fuel heater system and replaced some heater hoses on the engine.


Had a few spare HEMTT/7 ton driveshafts laying around in crates. They are 46in collapsed length. The 915a1 has a 41in working length. Had a local shop cut it down so i could use it. Current shaft has a little play in the slip yoke so an easy fix for it.


Moved an 816 and 870A1 about 40mi to a easier place to work on the trailer where its dry. 915 didnt have much of an issue hauling it.

 

[Ajax MD]

Wow, the 816 looks like a toy in comparison.
Does the 915 have engine coolant heat for the cab or are you without heat since deleting the fuel heater?

22F in Maryland this morning...brrr.

 

[simp5782]

Wow, the 816 looks like a toy in comparison.
Does the 915 have engine coolant heat for the cab or are you without heat since deleting the fuel heater?

22F in Maryland this morning...brrr.

The system is originally setup to go from the engine to the fuel heater unit to the cab heater core then back to to the engine. I just ran it from the engine to the heater core directly.

 

[simp5782]

Got the ProTote setup installed for use. Ran out to central OK to pick up this $1500 M923 and carried it back using it. Pulled a front drive cap for better towing.

Smooth enough ride that in Eastern OK i removed a valve cap from one of the rear wheels to check tire pressure in case i needed a spare for a steer tire. Left the valve cap on the outer wheel. Was still on the outer wheel 440mi later.


Avg 6.5mpg for the 1100mi trip out and back.

 

[Lukes_deuce]

Swapped the 11R24s out for 395 MVTs for a few trips i gotta take. I had a decent offer for the 11R24s i had on it so yea sold those. I am acquiring some 12R24.5 casings and wheels. Just waiting to find enough to get em recapped.

Bypassed the fuel heater system and replaced some heater hoses on the engine.


Had a few spare HEMTT/7 ton driveshafts laying around in crates. They are 46in collapsed length. The 915a1 has a 41in working length. Had a local shop cut it down so i could use it. Current shaft has a little play in the slip yoke so an easy fix for it.


Moved an 816 and 870A1 about 40mi to a easier place to work on the trailer where its dry. 915 didnt have much of an issue hauling it.

Hey Simp,

Just admiring your pics and work on the 915. I have one question. Isnt the 870a1 a folding neck trailer? How did you get a loaded trailer on the 915 without a winch?

 

[simp5782]

Hey Simp,

Just admiring your pics and work on the 915. I have one question. Isnt the 870a1 a folding neck trailer? How did you get a loaded trailer on the 915 without a winch?

Used the wrecker to lift and lower the neck. Even once it was on the trailer. I had the front skids blocked up so i could still get back under it

 

[Lukes_deuce]

Used the wrecker to lift and lower the neck. Even once it was on the trailer. I had the front skids blocked up so i could still get back under it

Very cool. You always come up with some nice tricks!

 

[simp5782]

Installed some ECCO mirror mounted strobes. Got the heated mirrors all wired up as well. Threw on some black camo pattern to go with the green.

Hooked the 45' East flatbed up to go to Denver. Was a nice little buy for $2700. Air ride trailers are nice.

 

[Russ Knight]

Nice rig pal! And thanks for turning up my pump when you were here. It makes a big difference!

 

[simp5782]

Nice rig pal! And thanks for turning up my pump when you were here. It makes a big difference!

Dont burn the new rubber off the ole girl.

 

[simp5782]

Swapped the stock manifold for the Pulse type. You can see the smaller port differences. Part # M3801912 from Interstate Mcbee. $350 shipped in. Came with everything including new bolts. Swapped on the HT4B turbo. Rerouted the turbo oil train to a lower location to account for how the turbo had it set up.
And changed the oil. Went with a Fleetguard 3380 as a main oil filter with the glass media. Also added a Digital Pyro.

Turbo metal drain : 3044929


Scored a New in the box Parker 308813 PTO that was listed for a HEMTT setup that has an air shift off Ebay. Designed for the HT740 but it and the HT754CR are the same transmission with only a few gear differences. This will run the 45k rear winch since the Hydraulic pump that goes on the older CAT transmission PTO uses the same spline count and bolt pattern. I hope to be able to put the PTO thru the access panel in the floor and be able to lay down in there with the passengers seat removed.

Going to rig up an adjustable air solenoid to run the throttle adjustment.

Going to replace the fuel filter tomorrow and swap the fuel button to a #7

 

[Another Ahab]

Swapped the stock manifold for the Pulse type. You can see the smaller port differences. Part # M3801912 from Interstate Mcbee. $350 shipped in. Came with everything including new bolts. Swapped on the HT4B turbo.

What did you do in the way of gaskets for each of the fits?

Maybe air fittings don't require gaskets like liquid fittings, and maybe the heat would fry any gaskets anyway, not sure there. I don't know much, simp5782.

But I WANT to know. What's the story?

 

[simp5782]

Had to loosen and turn transmission filter return fitting and got the PTO installed. The cross 53 series double pump bolted right in that comes on the 916/920s. Had to install the discharge lines before putting the pump in the access panel hole. Then installed the tank suction lines before putting it on the pto.

Using a 24v parker solenoid for the actuation circuit. Gotta hook those lines up tomorrow.

 

[Another Ahab]

Had to loosen and turn transmission filter return fitting and got the PTO installed. The cross 53 series double pump bolted right in that comes on the 916/920s.

Doesn't appear to be any gasket at the pump fitting, is that not needed, or am I just not seeing that right?