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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: busme66 on December 25, 2010, 04:16:52 AM

Title: Eagle rear end gear ISM
Post by: busme66 on December 25, 2010, 04:16:52 AM
Can you tell me what some options are to find one
of the rear ends I can use with my ISM.
Title: Re: Eagle rear end gear ISM
Post by: rv_safetyman on December 25, 2010, 06:28:36 AM
If I recall from your other posts, you have an '85 Eagle 10.  That has a drop box and the only real options are the 3.36 and 3.73.  The last I checked, the 3.36 are getting hard to find and very costly (new).

Jim
Title: Re: Eagle rear end gear ISM
Post by: Busted Knuckle on December 25, 2010, 07:11:14 AM
Call Sonny Gray he'll let you in on all kind of options! ;)
;D  BK  ;D
Title: Re: Eagle rear end gear ISM
Post by: Ericbsc on December 25, 2010, 07:34:54 AM
The 3:73 is the most common. With 24.5 tires rpms will be about 2100 @70mph. If you use the allison 6 speed you can program the5th, and 6th overdrive to be in the 2400-2500 range. Seemed to be my best option. I am going from an 8-71 with an mt-654 to a series 60 with 4000 allison.
Title: Re: Eagle rear end gear ISM
Post by: luvrbus on December 25, 2010, 08:04:50 AM
If you go with the World Transmission do a lot of shopping there are 4:10 ratios out there they are just hard to find I have one in the shop but it is part of my 401 k  lol.
You can also have gears cut for the dropbox @ Commercial Gear in Pompano FL for 4 grand+ I posted all the gear ratios for the Eagle here for you now the 3:36 is getting hard to find as the 3:38 replaced it.
Hal hit the nail on the head to get full performance from the 4 strokes the gearing has to be right or you defeat the purpose but the bus people do things a little different and it works or it doesn't.
Eric we are not 2400 to 2500 rpm on the 60 series are we?


good luck
Title: Re: Eagle rear end gear ISM
Post by: TomC on December 25, 2010, 08:56:22 AM
3.73 ratio with 11R-24.5 (476rpm) tires and the Allison B500 World transmission, in fourth direct you'll be at 1627 @ 55, 1775 @ 60, 1923 @ 65.  Then in fifth .74 overdrive, you'll be at 1423 @ 65, 1532 @ 70, 1642 @ 75.  If programmed in, 6th gear might shift in at 75mph which would drop to 1420.  Good choice for the bus.  Good Luck, TomC
Title: Re: Eagle rear end gear ISM
Post by: luvrbus on December 25, 2010, 10:09:11 AM
Bad choice Tom you have the ISM and the series 60 outside the 1200- 1300 rpms  where they achieve peak torque and fuel mileage theirs will suck at those rpms



good luck
Title: Re: Eagle rear end gear ISM
Post by: TomC on December 25, 2010, 11:45:15 AM
All Series 60's and ISM Cummins from the factory have a recommended cruise RPM of between 1400-1600.  None of the engines have cruise rpm at the same as peak torque RPM.  Otherwise, turbo 2 strokers would be cruised in the 1200-1400rpm range-and we all know how much performance 2 strokers have at that speed.  New DD engines from Detroit have maximum torque at 1100rpm with 1000rpm not to low.  But recommended cruise speed is between 1300-1500rpm.  Having an engine cruise at a lower RPM is not necessarily a guarantee of better fuel mileage.  One of the options on trucks now is a gauge for instantaneous mpg readout.  There are instances where you can get better fuel mileage at a higher RPM then the lowest RPM.  Good Luck, TomC
Title: Re: Eagle rear end gear ISM
Post by: busme66 on December 25, 2010, 01:45:33 PM
Were would I start looking for these rear ends and what different things do they come out of?
Title: Re: Eagle rear end gear ISM
Post by: blue_goose on December 25, 2010, 03:48:30 PM
Pro Gear in Orlando FL gave me a price of 1600 to regear my Eagle rear.
Jack
Title: Re: Eagle rear end gear ISM
Post by: luvrbus on December 25, 2010, 04:07:08 PM
www.eprogear.com (http://www.eprogear.com) not 1600 any longer that won't buy the ring gear and pinon anymore they are good people, it would help if we knew what area of the country you live in ::)


good luck

Title: Re: Eagle rear end gear ISM
Post by: Tom Y on December 25, 2010, 07:31:14 PM
Busme66, I got my 3.38 gears and dropbox from a guy in MO. He got my 4:10 gears in the deal. Not sure if they are still around. Good Luck Tom Y
Title: Re: Eagle rear end gear ISM
Post by: Ericbsc on December 25, 2010, 07:58:16 PM
Not at 2400 yet!!LOL The way i HAVE IT FIGURED i SHOULD BE AT APP 1450 IN 5TH AT 7O MPH.
Title: Re: Eagle rear end gear ISM
Post by: boxcarOkie on December 26, 2010, 05:20:14 AM
Quote from: luvrbus on December 25, 2010, 08:04:50 AM
I have one in the shop but it is part of my 401 k  lol.
good luck

You crack me up!  About 1650 at 72mph for what it is worth, and about -14.8 on the MPG.  If mine ever goes out, I am just going to hitch up the tractor take it out in the back part of the yard, bury it and use it for a "furnished storm cellar."

DS
[aka:BCO]
Title: Re: Eagle rear end gear ISM
Post by: David Anderson on December 26, 2010, 07:14:10 AM
Quote from: luvrbus on December 25, 2010, 04:07:08 PM
www.eprogear.com (http://www.eprogear.com) not 1600 any longer that won't buy the ring gear and pinon anymore they are good people, it would help if we knew what area of the country you live in ::)


good luck


Wow, Clifford,  You are better than a Google search.  You have a source for every bus component there is.  Live long and prosper my friend.

David
Title: Re: Eagle rear end gear ISM
Post by: luvrbus on December 26, 2010, 07:54:55 AM
David, there is a large gear outfit in Houston also www.differentialpartssupply.comI (http://www.differentialpartssupply.comi) believe Pro/gear and Differential Supply are both part of Global not for sure but I have ordered dropbox parts from Pro/Gear and it was shipped from Differential Supply in Houston.fwiw my buddy Norris put me on to these  


good luck.