transmission conversion

[jvrint]

Is it possible to convert a 18918B to a 20918B transmission if so what needs to be done

Thanks in advance

 

[389 Hood]

It's possible, but expensive. Input shaft, output shaft, output yoke all need to be changed out. Plus you have the rest of the driveline to consider. The forward, intermediate and rear sectional shafts are all rated for that particular torque output.

If you are the only person driving the truck, just don't try to pull 250k off the line with your foot buried in it. The 189 should be plenty to a correct responsible driver. Besides, what do you get out of the first 5-7 gears? Maybe 10-15 mph?

 

[jvrint]

Thanks for your reply sir
Im upgrading my engine to 625hp , I wont be grossing any more than 80,000 but I do cruise West Virginia often and was told the 18918B tranny would have to be change because it wont be able to handle the 2050 torque
Appreciate your knowledge

 

[389 Hood]

It must be an X-15 or 16. That or an older Cat.

Not sure what the 'B' designation means, but I think it's a non-overdrive.

It'll handle it, as long as the operator knows what torque range he's operating in. Lot's of variables. Mechanical engine, Electronic, full computer controlled? Unless it's 'tuned', rarely will a computer allow an engine to be operated at 100% of the torque value. A mechanical engine is going to give what is demanded of it by the pedal, load, manifold and rail pressure. Watching the pyrometer, fuel pressure, tach and listening to the engine will give you the best power without blowing the profits out of the stacks.

And make sure the engine can breathe.

 

[Crmsrail]

Yes, it’s possible to convert a 18918B to a 20918B transmission, but it’s not a simple swap. You’ll need to account for gearing, housing compatibility, and possibly upgrade supporting components like couplers and mounts. It’s also essential to verify lubrication and alignment specs before installation. At CRMSrail, we always recommend working with a certified technician or OEM service guide to ensure reliability and safety after the conversion.