Mc5a rear end

[Lin]

I was having a "get to know your drive train day" and wanted to find my rear axle ratio.  The book says the 3.36 was standard and 3.70 was an available option.   Did Greyhound go with the standard or the option back in them there days?  I guess I could hunt for numbers on it tomorrow, but it is not tomorrow yet, so why not ask?

[TomC]

If you have a tachometer and 12R-22.5 tires (485rpm) then at 60mph you'd be turning 1795rpm with the 3.70's and 1630rpm with the 3.36.  Good Luck, TomC

[jjrbus]

lift both rear wheels, mark both tires, mark the driveshaft, slowly rotate the tires, trying to keep them both rotating the same, rotate them 1 full turn, count the turns of the driveshaft



over 3 turns, 3.36   
just under 4 turns, 3.70

With the age of our bus's the rear end could have been changed several times, so what came from the factory no longer applies.   Jim   

[Tom Y]

Lin, I would think the 3.70 was the standard. My 5C had a 4.10.  Tom Y

[luvrbus]

Tom, wasn't the reason for the 4.10 gear because of the option of the Allision that you had in the later models with the V671 my 5 had the 3.70 and I changed to 3.36 was my understanding on the older 5 it was 3.36 or 3.70 depending on the area the bus was in service  so said Sam   good luck

[Tom Y]

My 5C had a 8v71 with a Spicer.   Tom Y

[makemineatwostroke]

the 4.10 was the standard gearing for the 8v71 and the 6v71 for the 5C but had options, 5A and 5Bs were 3.36 or 3.70 as Greyhound purchased most of those

have a great day

[kyle4501]

Raise 1 side of the drive axle & turn it 2 revolutions while counting turns of the drivr shaft. There's your ratio. 

[pvcces]

And you only have to jack up one side; it's easier to get an accurate reading, too.

I can't think of any good reason to turn both rear wheels.

Tom Caffrey

[jjrbus]

I thought we had jacked up both rear wheels. But I have no memory so am sure you gentlemen are right. My 5C with the 6V71 automatic has the 4.10 rear end. That I am sure of as I wrote it down!!  Jim