Bandit's M931 Repower thread

[Bandit02]

It has begun...

I finally got my kitty home. This is a 1995 CAT 3406B, equipped with 425 HP, jakes and oil cooler. Paired to it, a surprisingly (thought it was a 10 spd at first) Eaton 7 spd twin countershaft transmission. The engine is a running take out and it wasn't smoking or knocking or doing anything bad when I bought it. I also have a intercooler, front engine mounts, intake piping and some other misc. items from the donor setup.

All said and done $3500 + GST

I am quite excited to see how the ol girl will do pulling the lowbed, and as one of my friends said "Once you go Cat, you never go back!".

 

[srodocker]

Should be awesome. Cant wait to see the build.

 

[wreckerman893]

Here Kitty, Kitty, Kitty......................

 

[74M35A2]

If the Cat it is out of a US market road use vehicle, the starter/alternator will likely be 12V. If out of construction equipment, it may be 24V. That alternator is a standard J-180 short type mount, the military one will not fit that bracket correctly. The starter likely will carry over if your original engine is the NHC 250, as they are common SAE mount patterns, but count the number of pinion teeth on each before you swap it over or measure tooth spacing on flywheel to confirm if the Cat did not include the starter, I have measurements and parts if you need. The larger engines typically use an 11 tooth starter pinion gear.

Very interested in the transmission to transfer case clearance and connection once installed, in addition to what you go with for the clutch actuation workings and shift tower. Price seems decent for what you acquired and if you were able to see it run first.

Here is something similar to your first pic, but this one is connected as a driver (Cummins N14):

 

[Bandit02]

If the Cat it is out of a US market road use vehicle, the starter/alternator will likely be 12V. If out of construction equipment, it may be 24V. That alternator is a standard J-180 short type mount, the military one will not fit that bracket correctly. The starter likely will carry over if your original engine is the NHC 250, as they are common SAE mount patterns, but count the number of pinion teeth on each before you swap it over or measure tooth spacing on flywheel to confirm if the Cat did not include the starter, I have measurements and parts if you need. The larger engines typically use an 11 tooth starter pinion gear.

Very interested in the transmission to transfer case clearance and connection once installed, in addition to what you go with for the clutch actuation workings and shift tower. Price seems decent for what you acquired and if you were able to see it run first.

Here is something similar to your first pic, but this one is connected as a driver (Cummins N14):


View attachment 583385

View attachment 583388

I believe the starter will swap over as it was in a truck before. I know the alternator is 12v but I'll deal with that as I get to it.

The trans will fit underneath, it's shorter then the Allison so a proper jack shaft will need to be made but that's small potatoes. The shift tower came with the trans but it was cut in half, so when I cut a hole in the floor I can weld on a shifter setup that works for the room I have in cab. As for the clutch linkage I haven't thought about it yet, ways away. This is a huge project for me and it'll take time. The results are worth it though.

I will sell the NHC250/Allison to whomever wants it as they're practically new..look like new since refurb and it runs flawlessly. The catch is you have to come and get it, no delivery haha. Sells for cheap too. I don't need it.

 

[silverstate55]

WOW this is going to be awesome! Can't wait to see how it goes!!

 

[sweetk30]

don't forget the oil pan needs to be a front sump . . . . looks like CAT has rear sump .

 

[grendel]

In... I have a 3406B sitting here...

 

[Bandit02]

The 250 on my truck is rear sump

 

[lindsey97]

I might be interested in the Allison transmission.

 

[sweetk30]

The 250 on my truck is rear sump

I just recall the 8.3 cummins a2 trucks have front sump is all.

but I am sure you will figure it out .

cant wait to see end results . . . opcorn:

 

[Bandit02]

Didn't get much done today.

Replaced some missing injector line spacers, pulled off the flywheel & seized pilot bearing for machining and access to replace the rear main seal, cleaned the trans up so I can have it inspected by a Eaton trans re-builder I know.

 

[red]

Any updates?

 

[Bandit02]

Well. Got the front & rear main seals replaced, flywheels in machined with a new pilot bearing installed, new fuel hoses, filters, jakes wired up inside the rockers. Transmission is at my tranny guy, turns out it's a big 5 spd with 5th as direct, the issue is the mainshaft is damaged and no one here or on the moon has a replacement anywhere so I may need a new tranny, maybe a 15 spd? Little things like locating a air compressor & power steering pump as they're both missing and have nothing even for a core. This is a very expensive investment....the OEM lifting eyes front & rear were $600 alone.

The engine and trans in the truck is still intact to keep it mobile. It's free to a good home to anyone who wants it. The catch is your coming here to get it/pull it out. Don't be bummed though, for a shiny near new NHC250/MT654 combo that's still cheaper then what one of these big companies who sells army truck parts wants for a engine (14k for a reman NHC250 I saw recently).

I have no big shop or heavy lift capability either, so everything goes slowly, sadly.

Everything is also under snow, #$%@!! hate snow!.

 

[red]

Using the 5 speed would be the same as your stock auto, so no real benefits to fixing that trans. A 10-18 speed would be a great upgrade.

If I had a place to put those parts and was closer I'd take them. I know a guy in Arizona that might be interested in the engine

 

[Bandit02]

That 5 spd Eaton would be perfect, it's shorter then the auto and will take the torque of that B model. The auto wouldn't work with 425 HP flowing through it.

I agree, maybe a 10-18 spd would be ideal but now I may have to find one.

 

[Bandit02]

Just ran the serial number at my local Cat dealership and it's a 3406C, not a B. Very identical, pre-PEEC, still 425 HP.

Also, just found a main shaft for the trans, got my tranny guy assembling it. Once I purchase an Eaton easy-pedal clutch I'll bolt the two together.

 

[4XDesign]

It should pull like a train especially since it's not singled out. It's going to be awesome!

 

[Bandit02]

Got the 5 spd back today fully rebuilt. New bearings, seals, cross-shafts/fork/bushings. Everything, just needs a paint.

 

[JohnnyBM931A2]

Cool. What color are you going to paint it? OD green?