Reply
 
Thread Tools Display Modes
 
Old 05-27-2016, 07:22 PM   #1
Mini-Skoolie
 
Join Date: May 2016
Location: Elgin MN
Posts: 15
Year: 1986
Coachwork: Boyerville
Chassis: GMC
Engine: 8.2 Detroit
Rated Cap: 24 Pass
8.2 L Detroit Diesel

I have a 1986 Boyertown (Body) Trolley on a GMC School Bus Chassis, 8.2L Detroit Diesel, Allison 545 RM with a Rockwell International Differential with a 586 gear ratio, 10R-22.5 Tires.
I Have never owned a 8.2L aspirated Detroit Diesel. The question I have about the 8.2 Detroit is, when you take off from a dead stop the bus shift very well but when you hit four gear you are going 40mph, from 40 mph to 55 mph the engine is so noise that you cannot hardly hear inside of the bus the rpm are so high that it sounds like the engine is going to blow up. You let off the accelerator at 55 mph the bus will pull down in speed right away, the buses I drove with AT 545 when hitting four gear you can take foot off accelerator and bus does not pull down right away until you start braking
What can I do to fix this. Please Help! Ron
rty12345rty is offline   Reply With Quote
Old 05-27-2016, 07:32 PM   #2
Bus Crazy
 
opus's Avatar
 
Join Date: May 2010
Location: Montana
Posts: 1,614
Year: 1995
Coachwork: Blue Bird
Chassis: All-American R/E
Engine: 8.3 Cummins
Rated Cap: 72
With the 545 it should free roll forever. Sure you arent dragging a brake?
opus is offline   Reply With Quote
Old 05-27-2016, 07:43 PM   #3
Bus Nut
 
Join Date: Jun 2013
Posts: 252
Eww! 5.86 gear ratio in the differential... Yeah that thing was built to be a trolley. General rule of thumb is the numerically higher the gear ratio the slower it'll go. So probably anything above 45mph and you're pushing the engine. Kind of makes me wonder why they thought they needed that size engine because at that rate the thing could uproot redwood trees!
jake_blue is offline   Reply With Quote
Old 05-27-2016, 07:49 PM   #4
Bus Geek
 
Tango's Avatar
 
Join Date: Mar 2011
Location: Houston, Texas
Posts: 5,065
Year: 1946
Coachwork: Chevrolet/Wayne
Chassis: 1- 1/2 ton
Engine: Cummins 4BT
Rated Cap: 15
You might want to read up a little here...

Detroit 8.2L, Good and Bad - TheDieselGarage.com

Having owned a DD 6V53 (aka; the loudest engine ever built), I can sympathize. But from what little I know about the "Fuel Pinchers"...running any diesel at 3000 to 3300...there will noise. Lots of noise. And that's where they like to run.
Tango is offline   Reply With Quote
Old 05-27-2016, 08:55 PM   #5
Mini-Skoolie
 
Join Date: May 2016
Location: Elgin MN
Posts: 15
Year: 1986
Coachwork: Boyerville
Chassis: GMC
Engine: 8.2 Detroit
Rated Cap: 24 Pass
no I check that
rty12345rty is offline   Reply With Quote
Old 05-27-2016, 09:00 PM   #6
Mini-Skoolie
 
Join Date: May 2016
Location: Elgin MN
Posts: 15
Year: 1986
Coachwork: Boyerville
Chassis: GMC
Engine: 8.2 Detroit
Rated Cap: 24 Pass
How would I find out what I need for a gear ratio in the rear end
rty12345rty is offline   Reply With Quote
Old 05-27-2016, 09:31 PM   #7
Bus Crazy
 
Stu & Filo. T's Avatar
 
Join Date: Sep 2013
Location: Vacaville, Ca
Posts: 1,286
Year: 1988
Coachwork: Crown / Pusher
Engine: 8.3 Cummins
5:86 gears I'm Shocked Your even reaching 55, if your Going to be driving.This Any Distance get yourself some 4:10 0r 3:73's
Stu & Filo. T is offline   Reply With Quote
Old 05-27-2016, 10:57 PM   #8
Mini-Skoolie
 
Join Date: May 2016
Location: Elgin MN
Posts: 15
Year: 1986
Coachwork: Boyerville
Chassis: GMC
Engine: 8.2 Detroit
Rated Cap: 24 Pass
Quote:
Originally Posted by Stu & Filo. T View Post
5:86 gears I'm Shocked Your even reaching 55, if your Going to be driving.This Any Distance get yourself some 4:10 0r 3:73's
That way that engine is screaming after 40 mph You could not hear people talk inside of the trolley that was how load the engine was.
rty12345rty is offline   Reply With Quote
Old 05-27-2016, 11:01 PM   #9
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 4,229
Year: 1991
Coachwork: Carpenter
Chassis: International S3800
Engine: DT360
Rated Cap: 7 Row Handicap
its the torque cion verter in your AT545..

in my AT545 with a DTA360 engine if I floor it.. the engine runs at close to its max in the power band the whole time its floored.. this is by design... its a higher stall speed converter.. the AT545 has a pronounced 1st to 2nd gear ratio difference so you get a drop in RPM 1-2.. a little less in 2-3 ..and then 3-4 I barely notice a drop at all... and if im floored my 3-4 occurs about 45 or so and my bus still pulls hard until it reaches the governor at 65 MPH....

when I let off my bus slows down but not by the transmission... if I go down to '3' then my transmission engages 3rd gear and the bus pulls down very quickly...

if you shift cable is mis adjusted you may not be reachinfg 4th gear at all?

-Christopher
cadillackid is offline   Reply With Quote
Old 05-28-2016, 12:11 PM   #10
Mini-Skoolie
 
Join Date: May 2016
Location: Elgin MN
Posts: 15
Year: 1986
Coachwork: Boyerville
Chassis: GMC
Engine: 8.2 Detroit
Rated Cap: 24 Pass
Quote:
Originally Posted by cadillackid View Post
its the torque cion verter in your AT545..

in my AT545 with a DTA360 engine if I floor it.. the engine runs at close to its max in the power band the whole time its floored.. this is by design... its a higher stall speed converter.. the AT545 has a pronounced 1st to 2nd gear ratio difference so you get a drop in RPM 1-2.. a little less in 2-3 ..and then 3-4 I barely notice a drop at all... and if im floored my 3-4 occurs about 45 or so and my bus still pulls hard until it reaches the governor at 65 MPH....

when I let off my bus slows down but not by the transmission... if I go down to '3' then my transmission engages 3rd gear and the bus pulls down very quickly...

if you shift cable is mis adjusted you may not be reachinfg 4th gear at all?

-Christopher
Thanks I will check that to
rty12345rty is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 10:40 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.