Pschycopiolt
Member
- 21
- 55
- 13
- Location
- Des Moines Iowa
Hello all, my name Dave and this is my first post, so I bought this 5 ton the beginning of 2021 and like everything I own stock is dull.
So here we go I wanted to stay mechanical but wanted more power more then my stock 250/ allison combo. So I purchased a Big Cam 400 with that sorry low flow coolant setup from the junk yard- well it was pretty rough, I also purchased a 1600lbs 13 speed which came from a unit that I recognized and knew the trans was just installed in it before it being totaled out from a accident. Ok so the old lady wanted to help with this project so we got on the game and tore the engine down to get a correct liner number and to determine what was salvageable and what wasn't. Dropped the block and the crank off at the local machine shop and proceeded to order a overhaul kit, cam shaft, accessory drive, oil pan, heads, Jake's the whole works.
. Well me and a buddy pulled the 250 and allison out, sold the trans and engine. Started by running a lot of new air lines and removing the vents in the diffs and tcase and running those too the intake. Went ahead and pulled the jack shaft, front and rear also. Used a torch and cut the rivets off for the tcase ended up moving it back roughly 3 ½ inches rearward, when doing this the front bracket for the fuel tank was messing with my mounting of the tcase so I moved it about 1" forward.
On another note during this swap I also thought it was necessary to install a 934 expandable van body on it haha. But back to the story being the new engine does have Jake's on it we lifted the cab 3½" to ensure there was plenty of room which threw the whole measurement off for the van body. So there were several umm how do you want to put it negative Nancy's or naysayers about this from the get go which feeds my fire, a lot of folks said I had to use the fly wheel housing, oil pan, front engine mount- wrong I did use the fly wheel housing but nothing else, when it came time to install the engine and trans I did have to locate a sae2 bell housing I put a 2050ftlbs clutch in this, now it did not need the crank spacer or bell housing spacer, the only spacer that was used was a starter spacer which I had laying around. But between engine/trans swaps I'm almost 8" longer then the stock set up.
On too the engine remember I said low flow some know, some don't just to be blunt it sucks, so I converted it to a regular flow which wasn't hard, but I didn't want to change the radiator to use a poor style of a coolant system. I used a water pump from a big cam 3, had a hiccup with the fan hub the one that was on the BC400 was way high mounted, I ended up going back to the junk yard and finding a ntc-444 and robbed all of its fan hub and brackets being it is very similar to the 250 setup and as far as the drop and tensioning style. Threw it on and the plastic fan blades were 32" in diameter, the 250 was 26" and the BC400 was 28" so being I'm a inch off the radiator I chose not to run a fan shroud and it would work with out a issue.
The swap is really straight forward, not super hard maybe normal people may struggle with the conversions and crossing, but I have been working on semis for 15 years so I've got that going. So being the OE offset flywheel housing basically puts me center I notched the front crossmember and plated it where I wanted the front engine mount to sit. Now my oil filters are very large I did trim out the upper lip on the passenger frame so it will be easier to service.
The BC400 was originally front sump so I did get a rear sump pan and after getting the power plant in I had more clearance with it then the military aluminum one. Another difference between the 250 and 400 was power steering pumps the military used a belt driven pump vs my 400 was direct drive not a big issue it was very simple to add a couple lines and a resivor. So when the engine was a pile of parts I did have the PT Pump rebuilt and turned up for about 650hp and got a larger turbo for a N14 celect, and retarded the timing on the engine.
Okay on to some more of the details, jack shaft I ended up purchasing a standard slip with the same spline which was fine but the new forward slip was larger then my whole jack shaft, so I had my buddies at my Driveline shop lob 3"s off and throw it on a lath to turn it and thread it for a dust cover but it turned out nice.
At this point we're kinda having hiccups with the upper and lower coolant pipe, and a charge air pipe however we got the sub-frame done so I called another buddy and brought over his work wrecker and picked the van body up and I threw down ⅜" conveyor belt, then the 8"x4" sub-frame and another strap of ⅜" conveyor belt then a 4 x 4 then reinstalled the van body and welded it up and got it secured. In the beginning this was a joke to have it done before the snow flies but at this point between the machine shop messing me around for almost 3 months I'm behind schedule and what happens mistakes, yup pulled a rookie move and didn't double check wiring that got cut loose when we installed the sub-frame when we tow-barred it to my house didn't make it 3 blocks and ripped damn near the entire Abs harness out
shame on me I know better. So I added that to the list of things to be finished.
Got a charge air pipe made up and got the coolant lines together, I really beat my head hard against the wall trying to figure out a coolant resivor, after buying a new one for a freightliner M-class which was to thick and oval for anywhere under the hood, tried a couple different junk yard items I ended up using one from a Kenworth T-2000 I cut most of the stock mounting bracket off and notched the angle out to fit tightly against the hood rest. Now temps are dropping finally got coolant in it and plugged in, had my front shaft extended from 37 and some change to 4' of tube between carrier bearing and tcase, tcase to forward rear diff had it shortened.
I ended up taking a used transmission arm and notching it for a key way to extended the tcase linkage arm down low enough, and for what ever reason the military welded the Clevis on the rod for the linkage I found a offset Clevis with rod I attempted to screw it in to the end of the military one and luckily it was standard RH thread and it went so I did a lil trimming and cutting and that'll work for its purpose.
Getting closer to being done, down to the shift tower there are a lot of different fork plates and towers on the market, my fork plate is considered a front mount, then I had to locate the right tower, the one I went with was a straight stick from a 10 speed and freightliner combo being I wanted the 4" arm. After getting it in it is close but it will work and I bent the stick to put it more in the center. Fired it up for the first time, good oil pressure and ran smooth, but I think I've got a problem with a check valve fuel is draining back. I'm down to odd and end wiring stuff and clutch pedal and linkage.
So here we go I wanted to stay mechanical but wanted more power more then my stock 250/ allison combo. So I purchased a Big Cam 400 with that sorry low flow coolant setup from the junk yard- well it was pretty rough, I also purchased a 1600lbs 13 speed which came from a unit that I recognized and knew the trans was just installed in it before it being totaled out from a accident. Ok so the old lady wanted to help with this project so we got on the game and tore the engine down to get a correct liner number and to determine what was salvageable and what wasn't. Dropped the block and the crank off at the local machine shop and proceeded to order a overhaul kit, cam shaft, accessory drive, oil pan, heads, Jake's the whole works.
. Well me and a buddy pulled the 250 and allison out, sold the trans and engine. Started by running a lot of new air lines and removing the vents in the diffs and tcase and running those too the intake. Went ahead and pulled the jack shaft, front and rear also. Used a torch and cut the rivets off for the tcase ended up moving it back roughly 3 ½ inches rearward, when doing this the front bracket for the fuel tank was messing with my mounting of the tcase so I moved it about 1" forward.On another note during this swap I also thought it was necessary to install a 934 expandable van body on it haha. But back to the story being the new engine does have Jake's on it we lifted the cab 3½" to ensure there was plenty of room which threw the whole measurement off for the van body. So there were several umm how do you want to put it negative Nancy's or naysayers about this from the get go which feeds my fire, a lot of folks said I had to use the fly wheel housing, oil pan, front engine mount- wrong I did use the fly wheel housing but nothing else, when it came time to install the engine and trans I did have to locate a sae2 bell housing I put a 2050ftlbs clutch in this, now it did not need the crank spacer or bell housing spacer, the only spacer that was used was a starter spacer which I had laying around. But between engine/trans swaps I'm almost 8" longer then the stock set up.
On too the engine remember I said low flow some know, some don't just to be blunt it sucks, so I converted it to a regular flow which wasn't hard, but I didn't want to change the radiator to use a poor style of a coolant system. I used a water pump from a big cam 3, had a hiccup with the fan hub the one that was on the BC400 was way high mounted, I ended up going back to the junk yard and finding a ntc-444 and robbed all of its fan hub and brackets being it is very similar to the 250 setup and as far as the drop and tensioning style. Threw it on and the plastic fan blades were 32" in diameter, the 250 was 26" and the BC400 was 28" so being I'm a inch off the radiator I chose not to run a fan shroud and it would work with out a issue.
The swap is really straight forward, not super hard maybe normal people may struggle with the conversions and crossing, but I have been working on semis for 15 years so I've got that going. So being the OE offset flywheel housing basically puts me center I notched the front crossmember and plated it where I wanted the front engine mount to sit. Now my oil filters are very large I did trim out the upper lip on the passenger frame so it will be easier to service.
The BC400 was originally front sump so I did get a rear sump pan and after getting the power plant in I had more clearance with it then the military aluminum one. Another difference between the 250 and 400 was power steering pumps the military used a belt driven pump vs my 400 was direct drive not a big issue it was very simple to add a couple lines and a resivor. So when the engine was a pile of parts I did have the PT Pump rebuilt and turned up for about 650hp and got a larger turbo for a N14 celect, and retarded the timing on the engine.
Okay on to some more of the details, jack shaft I ended up purchasing a standard slip with the same spline which was fine but the new forward slip was larger then my whole jack shaft, so I had my buddies at my Driveline shop lob 3"s off and throw it on a lath to turn it and thread it for a dust cover but it turned out nice.
At this point we're kinda having hiccups with the upper and lower coolant pipe, and a charge air pipe however we got the sub-frame done so I called another buddy and brought over his work wrecker and picked the van body up and I threw down ⅜" conveyor belt, then the 8"x4" sub-frame and another strap of ⅜" conveyor belt then a 4 x 4 then reinstalled the van body and welded it up and got it secured. In the beginning this was a joke to have it done before the snow flies but at this point between the machine shop messing me around for almost 3 months I'm behind schedule and what happens mistakes, yup pulled a rookie move and didn't double check wiring that got cut loose when we installed the sub-frame when we tow-barred it to my house didn't make it 3 blocks and ripped damn near the entire Abs harness out
shame on me I know better. So I added that to the list of things to be finished.Got a charge air pipe made up and got the coolant lines together, I really beat my head hard against the wall trying to figure out a coolant resivor, after buying a new one for a freightliner M-class which was to thick and oval for anywhere under the hood, tried a couple different junk yard items I ended up using one from a Kenworth T-2000 I cut most of the stock mounting bracket off and notched the angle out to fit tightly against the hood rest. Now temps are dropping finally got coolant in it and plugged in, had my front shaft extended from 37 and some change to 4' of tube between carrier bearing and tcase, tcase to forward rear diff had it shortened.
I ended up taking a used transmission arm and notching it for a key way to extended the tcase linkage arm down low enough, and for what ever reason the military welded the Clevis on the rod for the linkage I found a offset Clevis with rod I attempted to screw it in to the end of the military one and luckily it was standard RH thread and it went so I did a lil trimming and cutting and that'll work for its purpose.
Getting closer to being done, down to the shift tower there are a lot of different fork plates and towers on the market, my fork plate is considered a front mount, then I had to locate the right tower, the one I went with was a straight stick from a 10 speed and freightliner combo being I wanted the 4" arm. After getting it in it is close but it will work and I bent the stick to put it more in the center. Fired it up for the first time, good oil pressure and ran smooth, but I think I've got a problem with a check valve fuel is draining back. I'm down to odd and end wiring stuff and clutch pedal and linkage.
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