Rear Tandem Axle on a single axle Bus?

[karrlot]

I have a 1991 Ward on a 3800 International chassis. It has a DT466 and an MT643 Allison.

The line setting ticket said that it had an International N-175 - 17500# rear axle 4.75 ratio.

The service records indicated that they replaced the rear end.

Now the differential has a tag with a serial number from Weller Reman. I called them and gave them the number from the tag.

They told me it was an RA14GDCR with a 4.78 ratio.

As I am looking in my service manuals it indicates that this is the differential for a rear tandem axle.

Would they use the differential for a rear tandem axle on a single axle vehicle? Or do you think something about the records is messed up?

[Brad_SwiftFur]

Originally Posted by karrlot

I have a 1991 Ward on a 3800 International chassis. It has a DT466 and an MT643 Allison.

The line setting ticket said that it had an International N-175 - 17500# rear axle 4.75 ratio.

The service records indicated that they replaced the rear end.

Now the differential has a tag with a serial number from Weller Reman. I called them and gave them the number from the tag.

They told me it was an RA14GDCR with a 4.78 ratio.

As I am looking in my service manuals it indicates that this is the differential for a rear tandem axle.

Would they use the differential for a rear tandem axle on a single axle vehicle? Or do you think something about the records is messed up?

I have the N-175 axle in my bus; it's a pretty common axle.


4.78 is also a somewhat common ratio too.


IH, being like many other corporations, likes to minimize costs, so they use that axle in both the single and tandem axle (for the rear axle, in this case) configurations, instead of stocking 2 different axles to do the same job. The main difference between a school bus and road tractor usage will be the gear ratio - road tractors often have ratios in the mid 3's, since the larger engines don't spin as fast.