big cam 3 and allison 4500 RDS possible?

[akita91]

Threaaad after thread,
Found out allison 4xxx series have 6 gears which will drop rpm to 1800 or 2100 and 70mph,per local allison dealer they can swap it out but not sure if it will work.
as far as i understand , i have to put on
1.actual transmission with matching bellhousing
2.Cut off or lengthen shaft
3.Add transmission position linkage
4.Transmission speed sensor (where to hookup to engine ? )
5. Constant 12v supply for Allison TCM
6. Reflash TCM according to my rear ratio,tire sizes,engine rpm powerband.

All extra features,sensors that transmission get nothing as big cam doesnt have computer.
What steps do i miss?
Transmission might cost 1500-4500,labor if i do myself idk if i can handle,shop 1-2k ?

Other way is to get super singles and i can get 68 but wont be able to haul dry van. Which way is more feasible ?
i want to be flatbedder,cant sit on my ass while getting loaded for hours.gotta work all the time

 

[simp5782]

Threaaad after thread,
Found out allison 4xxx series have 6 gears which will drop rpm to 1800 or 2100 and 70mph,per local allison dealer they can swap it out but not sure if it will work.
as far as i understand , i have to put on
1.actual transmission with matching bellhousing
2.Cut off or lengthen shaft
3.Add transmission position linkage
4.Transmission speed sensor (where to hookup to engine ? )
5. Constant 12v supply for Allison TCM
6. Reflash TCM according to my rear ratio,tire sizes,engine rpm powerband.

All extra features,sensors that transmission get nothing as big cam doesnt have computer.
What steps do i miss?
Transmission might cost 1500-4500,labor if i do myself idk if i can handle,shop 1-2k ?

Other way is to get super singles and i can get 68 but wont be able to haul dry van. Which way is more feasible ?
i want to be flatbedder,cant sit on my ass while getting loaded for hours.gotta work all the time

Why not just get rid of the 4.90 gears for some 4.30s or 3.73s?

Or i have everything you would need to put the CAT 7155 transmission in it with a .83 overdrive. and you can haul 70 plus all day long

 

[akita91]

ive read your thread about it lil bit and it seems good idea for long haul ,what do i need besides transmission is there any drawbacks.

 

[Floridianson]

That's my problem and thought right now. 60 series 4.56 rears. Looks like my options are 3.73, 3.58 or 3.31. I am leaning to the 3.58. ProGear in Orlando want five thousand to do the swap. I like my Allison to bad it is just a four speed but my best option is just a gear change. That's the beauty of a 6x4.

 

[simp5782]

That's my problem and thought right now. 60 series 4.56 rears. Looks like my options are 3.73, 3.58 or 3.31. I am leaning to the 3.58. ProGear in Orlando want five thousand to do the swap.

Should be readily found at a truck junk yard. I got sent a picture the other day of a 915A2 hood on a OTR freighliner lol

 

[simp5782]

ive read your thread about it lil bit and it seems good idea for long haul ,what do i need besides transmission is there any drawbacks.

You gotta learn how to shift it. It takes some getting used to. I have the transmission. umbilical cord. adapter ring, flywheel, bellhousing, 1710 output yoke. You would need a shifter that are pretty easy to acquire. It mounts up the same, The A1 allison bellhousing is different so you gotta swap the mounts out. The Rear transmission mount is the same. You would need to fab up a shifter holder in the cab.

You can ask wreckman and NDT. a 915 with an NTC400 and a CAT 7155 will walk up or down hill even loaded. They just take some getting used to on shifting. Some folks hate it. You have to shift gears but air does the clutch part for you.

 

[simp5782]

You could also go to 12R22.5 or 11R24.5 or 12R24.5s on tires and a trailer would be able to ramp up.

 

[Floridianson]

Yea I had bought a full set of 11R24.5's that I never used and the truck came with 11R22.5 that did not change much for me. I need a gear set change just have to justify the money for a garage /carport queen.

 

[simp5782]

Yea I had bought a full set of 11R24.5's that I never used and the truck came with 11R22.5 that did not change much for me. I need a gear set change just have to justify the money for a garage /carport queen.

Text me a pic of your axle tags and see what i can come up with.

 

[akita91]

are you able to swap it for me ?and how much woudl cost complete swap ?

 

[akita91]

also,do you think i can rebuild engine to 600 hp later on,cant find specs for 7155

 

[simp5782]

also,do you think i can rebuild engine to 600 hp later on,cant find specs for 7155

a big cam III can go that high. may not live long. You would want to talk to Pittsburgh Power on that. They make some pretty crazy numbers from big cam's.

Set of hot injectors. HT4B or C and a pump mod you should be upwards of 520 or so. The CAT transmission is basically a manual transmission without a clutch pack. It is a triple countershaft setup. It will hold together. The rear clutch slips on Ponway's transmission somewhere around 1850/1900ft lbs of torque when he is pulling.

 

[akita91]

i thought about it and made conclusion that i might dont even need any tcm reflashing as 4500 allison all nearly the same ,idle 500-800 and shifts up to 2300rpm.why would i consider rear end ratio.if its off 400-500hp engine and than it should match straight forwards with little bit weird shifts other than that i dont see issues.