RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 10-19-2016, 11:26 PM   #15
Senior Member
 
MN_Traveler's Avatar
 
Join Date: Apr 2012
Location: Minneapolis, MN
Posts: 580
Shifting Allison 3000

Lots of good advice. To try to relate what I do: start the downhill run with speed under control (50?). Downshift to keep to that speed . If you speed up try downshifting to a lower gear. If the tranny does not allow the downshift , brake to a slower speed (40-45?) to allow the downshift. If I still gain speed , hit the exhaust brake . If you still speed up, brake to a slower speed (35-40?) to allow another downshift . (Turn off the exhaust brake if effect is too extreme) Bottom line: steeper grades = slower speed and lower gear. After you get the feel for it, you'll find your gear and speed based on the grade and likely not need to hit the brakes much at all. I typically find myself in lowered gear and hit the exhaust brake periodically to cut the speed a little (or leave it on if that gives me a stable speed). This works for me for grades up to 6%
__________________
- 2012 Fleetwood Expedition 36M -
MN_Traveler is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 10-20-2016, 02:42 AM   #16
Senior Member
 
DD788Snipe's Avatar
 
Newmar Owners Club
Spartan Chassis
Join Date: Jun 2013
Location: Apple Valley CA
Posts: 1,068
Quote:
Originally Posted by Dutch Star Don View Post
"RIDER FAN"......I can give you some advice on driving your coach, because I had the same coach for ten years (2005 Diplomat).

To start, and not to offend anyone, the old saying of going down a hill at the same speed you went up, is an old adage that doesn't apply to many modern coaches. My 05 Diplomat had the power to climb 6% - 7% grades at 60+ mph, even while towing, yet the Exhaust Brake was incapable of holding the coach back at those speeds on a 6% - 7% downhill.

Your Allison will NOT allow the engine to over rev and will NOT downshift if the rpm's are too high. Your exhaust brake has just enough power to MAINTAIN downhill speed when turned on at 55 mph or less on grades that are 5% or less.

Anything over that speed and your exhaust brake will do little for you. Anything over 5% and your coach will gain speed proportionally to the steepness of the grade.

Your first downshift when the exhaust brake comes on, is typically 6th to 5th. Again, only a little help on slight grades. Your next down shift will help, but still won't hold the coach back. On my Diplomat, I eventually had to get to 44-45 mph, a downshift to third, before the coach would hold on grades above 5%. So.....if you know it's a steep/long grade, you'll want to get down to the 44 mph speed. I short grade, you'll be back on flat land before the coach builds too much speed.

Here's the problem.....descending grades at 45 mph usually brings an onslaught of semi's and other RVers roaring down your back side. Many will say, who cares, but it can be disconcerting and I hated it. It typically took a lot of work, both selecting speed, stabbing brakes and paying attention to the overall grade when using the exhaust brake.

This may not be the answer you're looking for, but it's what I found worked best for your coach after ten years of driving my Diplomat all over the mountain ranges out west. The only one where all the rules go out the window is the Eisenhower grade in Colorado.

When I owned the Diplomat, I was towing a Chevrolet Silverado 4 door. I knew when I eventually changed coaches, my next coach would have an engine brake. The newer coaches allow the engine brake to work with the cruise control and automatically adjust speed on steep grades. It's now a lot less work and I can descend most grades at whatever the rest of the traffic is doing.

Couldn't have said it better myself Don.
__________________
[SIGPIC][/SIGPIC]
Craig & Carolyn Roberts Apple Valley, CA
Toad: 2017 GMC Canyon 4X4 Crewcab
DD788Snipe is offline   Reply With Quote
Reply

Tags
allison



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Shifting Allison 3000 to Neutral then Drive wagonmaster2 Allison Transmission Forum 12 09-28-2014 02:00 PM
Allison still shuddering. Allison 3000 Mystery Allison Transmission Forum 23 01-18-2014 07:45 PM
Allison 1000 shifting strangely FrankO Workhorse and Chevrolet Chassis Motorhome Forum 14 08-27-2008 05:33 AM
Allison 1000 shifting points BellaBo Workhorse and Chevrolet Chassis Motorhome Forum 16 04-23-2007 07:35 PM
shifting allison an engine rpm's tom41 Allison Transmission Forum 15 07-16-2006 12:00 PM


All times are GMT -6. The time now is 04:36 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.