Good combo? 8.3 Cummins/MT646

[chrisc-SKO]

Hey all. Working hard to find the right bus.

Curious what people think of the MT646 transmission when paired with a good engine like the 8.3 Cummins. Will be driving in mountains so curious if that combination would have enough get up and go for highway driving in those conditions? What would be the big downside to the 4 speed?

Also, in your opinion how many miles is too many when buying a used school bus? Some of these buses out there have more than 250,000 miles on them.

Thanks in advance for any guidance that you can give!

 

[WIbluebird]

Hey all. Working hard to find the right bus.

Curious what people think of the MT646 transmission when paired with a good engine like the 8.3 Cummins. Will be driving in mountains so curious if that combination would have enough get up and go for highway driving in those conditions? What would be the big downside to the 4 speed?

Also, in your opinion how many miles is too many when buying a used school bus? Some of these buses out there have more than 250,000 miles on them.

Thanks in advance for any guidance that you can give!

MT643 is lockup torque converter and can handle the power of an 8.3. It isn't as advanced as the MD3060 but works perfectly fine in older buses.

 

[PNW_Steve]

That is a solid combination.

I would make sure that you have a transmission temperature gauge especially for mountain driving.

 

[Ronnie-SKO]

As far as mileage on the bus it all depends. 250,000 on an 8.3 that has been taken care should not be a problem. The T444e or a 5.9 cummins are considered good for 250,000 with 50% of them needing a rebuild by that time.