Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-26-2007, 08:30 AM   #15
Rivet Master
 
2005 30' Classic
... , ...
Join Date: May 2005
Posts: 511
Images: 12
Good info guys - Thanks for the education.
__________________

__________________
GetOutDoors is offline   Reply With Quote
Old 07-27-2007, 02:56 PM   #16
Rivet Master
 
SilverCabin's Avatar

 
2014 27' Flying Cloud
Viera , Florida
Join Date: Oct 2006
Posts: 1,147
Yes, very good posts. I like Terry's 50% rule, that make's it pretty much a binary decision for me--OD off.

I have experimented with OD on and off and find that were only talking about one mpg difference on a flat wind free highway. I'd have to drive a lot of miles to save enough from that one mpg to cover a $3,000 transmission rebuild.

Towing my 23' makes my truck downshift from OD to third on as little a grade as an interstate overpass here in FL. So, even if I wanted to tow in OD, I'd always be switching it off before the overpasses. It's easier to just leave it off.

Randy
__________________

__________________
Randy and Pat Godfrey
Region 3 2nd VP, Newsletter Editor, Florida Unit
WBCCI# 7591 - AIR# 17017
2014 27FB Flying Cloud - SilverCabin II
2006 Lincoln Mark LT - Hoke

A journey of a thousand miles, begins with a cash advance
SilverCabin is offline   Reply With Quote
Old 07-27-2007, 03:16 PM   #17
Moderator
 
Stefrobrts's Avatar

 
1968 17' Caravel
Battle Ground , Washington
Join Date: Dec 2002
Posts: 11,911
Images: 50
Blog Entries: 1
My van's problem turned out to not be tranny, it was a bad u-joint - so that's a relief!

So using Terrys 50% rule, I guess I'm probably still ok. I have a 2800# trailer fully loaded, and a 6600# towing capacity. Because of the big truck/small load, I guess I'm ok. I still switch OD off when necessary, but I think on the flat it's ok to leave it on. I'm not worried about milage (it's the same towing or not), just that it's annoying to hear the engine running higher than it needs to.
__________________
Stephanie




Stefrobrts is offline   Reply With Quote
Old 07-27-2007, 06:48 PM   #18
Rivet Master
 
Mikethefixit's Avatar
 
1977 27' Overlander
Trotwood , Ohio
Join Date: Jul 2007
Posts: 2,153
Send a message via Yahoo to Mikethefixit
I have almost the same Question. We are just now lookinf for our first AS .We have 2001 F350/7.3liter /Harvester Diesel/Allision Tranny. This is a monster tranny.What about this setup, Are we in danger of loosing a tranny if we tow in OD?
__________________
Mikethefixit is offline   Reply With Quote
Old 07-27-2007, 09:10 PM   #19
Rivet Master
 
SilverCabin's Avatar

 
2014 27' Flying Cloud
Viera , Florida
Join Date: Oct 2006
Posts: 1,147
Mike,

Your monster truck would probably pull any Airstream and not notice. However, I would think the same advice applies. If it's downshifting out of OD to pull hills and bridges, it's generating heat. If it's doing that a lot or hunting for the right gear, I would switch off OD.

Randy
__________________
Randy and Pat Godfrey
Region 3 2nd VP, Newsletter Editor, Florida Unit
WBCCI# 7591 - AIR# 17017
2014 27FB Flying Cloud - SilverCabin II
2006 Lincoln Mark LT - Hoke

A journey of a thousand miles, begins with a cash advance
SilverCabin is offline   Reply With Quote
Old 07-29-2007, 11:52 AM   #20
Rivet Master
 
Mikethefixit's Avatar
 
1977 27' Overlander
Trotwood , Ohio
Join Date: Jul 2007
Posts: 2,153
Send a message via Yahoo to Mikethefixit
Randy Thank You
Kinda figured that would be the answer. Its good advise for everyone("If the tranny is searching for the correct gear ("TURN OF THE OD")I do listen to that Power Plant Randy,seems Ive driven desiels all my adult life(45 yrs OTR) from the 2cycle Detroit Desiel to CAT 855 CI Monsters.
We continue our search for just the rite AS. ,the truck is ready with brake controller mounted and the equilizing hitch in the warehouse,now to find the correct AS to go with this combo.
Thanks Randy
Roger
__________________
Mikethefixit is offline   Reply With Quote
Old 07-29-2007, 03:42 PM   #21
Rivet Master
 
Join Date: Dec 2002
Posts: 1,313
Images: 4
I'll make a couple of points that relate to the overdrive issue:

1. If you ride a pedal cycle with gears up a hill, and you are in too high a gear, you will feel a huge strain in your legs. Change down, pedal faster and you will feel less strain. That is a rough and non-scientific analogy which shows the extra strain you are putting on a transmission by risking using the overdrive.

2.By definition, in overdrive, the output drive from the gearbox is turning faster than the engine. If you strip down and dismantle a simple manual gear box, you will see that in top gear (not overdrive), the engine is coupled solidly and directly to the prop shaft connected to the back of the gearbox. There are no intermediate toothed gears which can break, or whose bearings can fail. When overdrive is engaged, the power is transferred across to a parallel shaft in the gearbox. The receiving gear has less teeth than the transmitting gear, so it rotates more quickly, and at the other end of this shaft, the drive is transferred back to the output shaft by another pair of meshed gears. You can see that in top gear, there is far less to fail. Overdrive units are inherently weaker because they introduce a complex path for the power, and this path is weaker than the direct physical connection in top gear. That has been the case in the simple manual gearboxes I have overhauled.

Those two reasons cause me to avoid towing in overdrive.
Nick.
__________________

__________________
Nick Crowhurst, Excella 25 1988, Dodge Ram 2500 Cummins Diesel. England in summer, USA in winter.
"The price of freedom is eternal maintenance."
nickcrowhurst is offline   Reply With Quote
Reply


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
Towing With a 1974 Ford F100 melprice Tow Vehicles 18 04-01-2014 07:34 PM
1989 370 Ford 460 Overheating ViewRVs Mechanics Corner - Engines, Transmission & More... 14 07-05-2004 04:46 PM
Front wheel drive ?? ALANSD Airstream Motorhome Forums 14 08-25-2002 01:47 PM
Ford Windstar Gordon Watt Tow Vehicles 61 08-23-2002 09:33 AM
U joints and drive shaft thenewkid64 Mechanics Corner - Engines, Transmission & More... 2 07-13-2002 05:07 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:28 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.