Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-09-2008, 04:34 AM   #1
Winnebago Camper
 
Join Date: Mar 2008
Location: Indian Rocks Beach, FL
Posts: 23
Our 08 Itasca 30B (9k miles) has developed a questionable trait: upshifting very late when first started (cold if you call 65F cold). Leaving our neighborhood, after sitting for a couple weeks, the motor stays in the lower gears even when rpm is over 2500 (with minimal acceleration on a flat road).

At other times, it does a very rapid, hard upshift like it has suddenly woke up.

This makes me wonder if it is not even getting into fifth gear because mpg has been consistent in the low 7’s (7.1, 7.3, with 7.5 for a high). This seems low because there is no Toad, our driving is on flat (usually FL) highways, outside temp is in the 60-90 range, and we average 60 to 65 on the highway. Plus very little metro driving.

Engine is the 6.8L Ford V-10. Tires are 95-psi front/85 rear. Toe-in good. Little to no generator use. Tow/Haul OFF. 19.5 tires. Battery has not been disconnected.

Can anyone advise:

1. Is the late shifting when ‘cold’ normal for the new Torqshift?
2. Is the occasional hard upshift normal for the new Torqshift?
3. What rpm is normal for this model at 60 mph in fifth gear? (Or where can I find the fifth gear and axle ratios - not in any of the manuals?)
Invent1 is offline   Reply With Quote
Old 12-09-2008, 04:34 AM   #2
Winnebago Camper
 
Join Date: Mar 2008
Location: Indian Rocks Beach, FL
Posts: 23
Our 08 Itasca 30B (9k miles) has developed a questionable trait: upshifting very late when first started (cold if you call 65F cold). Leaving our neighborhood, after sitting for a couple weeks, the motor stays in the lower gears even when rpm is over 2500 (with minimal acceleration on a flat road).

At other times, it does a very rapid, hard upshift like it has suddenly woke up.

This makes me wonder if it is not even getting into fifth gear because mpg has been consistent in the low 7’s (7.1, 7.3, with 7.5 for a high). This seems low because there is no Toad, our driving is on flat (usually FL) highways, outside temp is in the 60-90 range, and we average 60 to 65 on the highway. Plus very little metro driving.

Engine is the 6.8L Ford V-10. Tires are 95-psi front/85 rear. Toe-in good. Little to no generator use. Tow/Haul OFF. 19.5 tires. Battery has not been disconnected.

Can anyone advise:

1. Is the late shifting when ‘cold’ normal for the new Torqshift?
2. Is the occasional hard upshift normal for the new Torqshift?
3. What rpm is normal for this model at 60 mph in fifth gear? (Or where can I find the fifth gear and axle ratios - not in any of the manuals?)
Invent1 is offline   Reply With Quote
Old 12-09-2008, 07:04 AM   #3
Winnebago Master
 
tderonne's Avatar
 
Join Date: Dec 2003
Location: Motor City, Mich
Posts: 1,000
First the specs:

245/70R19.5 tire, 33" OD, 627 revs/mile
5.38 axle
.717 top gear ratio

Using the above gets you:
2428 RPM @ 60 MPH in top gear
3372 RPM @ 60 MPH one gear down

That said, you may not have 245 tires? The 18,000 pound GVWR chassis may use narrower tires?

Also don't assume your tach is correct. It's close, but don't try to use it to the last 50 RPM. (50 RPM at 2500 RPM is 2%, not too bad for any gauge)

As for the shifting. I'd expect the shift points to be the same over time, with maybe a little change for trans temp. But overall, there's one shift cal for all the same tire and axle combo, regardless of GVWR. Your smaller coach may really want a slightly different schedule than a 35' one, but they are the same.

If it's not doing what it's commanded to do, it ought to set a code. Being an '08, it might be worth a trip to the dealer to check all codes, and take a quick test drive.
__________________
Tim.

tderonne is online now   Reply With Quote
Old 12-09-2008, 03:42 PM   #4
Winnebago Camper
 
DeanLinAZ's Avatar
 
Join Date: Aug 2002
Location: Sun City West, AZ, USA
Posts: 45
My experience and memory recalls that most of the automatic transmission vehicles that I have owned (cars & motorhomes) all were slow on the up-shift during the initial startup and drive-off from cold, even in Arizona. Just apply power easily when you first drive away.

Sounds normal to me.
__________________
DeanLinAZ
2004 Journey 39W/330 Cat
2013 MINI Cooper S Hatchback
DeanLinAZ is offline   Reply With Quote
Old 12-09-2008, 03:52 PM   #5
Winnie-Wise
 
Fakrwee's Avatar
 
Join Date: Mar 2007
Location: Carlsbad, Ca.
Posts: 310
This may not apply to your situation but it's worth a shot. Electronic transmissions have a memory. They adjust to your way of driving.

Try disconnecting the battery for 10 or 15 minutes. Start up the MH like you usually do and start driving. Sometimes it changes shift points.

Good Luck
Tom
__________________
2007 Itasca Suncruiser 33V
2009 Ford Flex Ltd. AWD Fa. Toad
2010 Jeep Rubicon offroad Toad
Fakrwee is offline   Reply With Quote
Old 12-09-2008, 05:38 PM   #6
Winnebago Master
 
tderonne's Avatar
 
Join Date: Dec 2003
Location: Motor City, Mich
Posts: 1,000
The only thing that is learned is line pressure adjustment to keep shift times to preset times. Shift schedule doesn't change.
__________________
Tim.

tderonne is online now   Reply With Quote
Old 12-13-2008, 05:30 AM   #7
Winnebago Camper
 
Join Date: Mar 2008
Location: Indian Rocks Beach, FL
Posts: 23
Tim,

Thanks for the information. It's exactly what I need. And, yes, the tires are 245/70R19.5.

And your advice on gauges is dead-on too, I've designed several electronic gauges. +/- 2% or +/- 50 rpm would be very good for an automotive tach.

Just a point of curiosity,in the pre-electronic days I believe a mechanical rod that was connected to the throttle varied the shift point (i.e. upshifted at a higher rpm when your foot was in it) and the vacuum modulator made the upshift faster and harder when vacuum was low (again when your foot was in it).

When you said "The only thing that is learned is line pressure adjustment to keep shift times to preset times. Shift schedule doesn't change." Does that mean that the rpm vs throttle opening schedule remains the same for upshifts regardless of the "learning", and that "learning" only chnages the hardness/softness of the shift changes?

In any case, it appears that the trans is making it to fifth gear, and the 7.2 mpg on flat roads at 63 mph is something I'll have to live with.

Thanks again for the excellent info,

John
Invent1 is offline   Reply With Quote
Old 12-13-2008, 08:31 AM   #8
Winnebago Master
 
tderonne's Avatar
 
Join Date: Dec 2003
Location: Motor City, Mich
Posts: 1,000
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Invent1:

When you said "The only thing that is learned is line pressure adjustment to keep shift times to preset times. Shift schedule doesn't change." Does that mean that the rpm vs throttle opening schedule remains the same for upshifts regardless of the "learning", and that "learning" only changes the hardness/softness of the shift changes?
John </div></BLOCKQUOTE>

Exactly. The base shift tables are all vehicle speed vs. throttle position. And the only thing that is learned is a small adjustment in the shift pressure (EPC in Ford speak, Electronic Pressure Control, and it's not just dependent on throttle, like in the old days, "calibratable beyond explanation" is the best I can describe it).
__________________
Tim.

tderonne is online now   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
50 amp. surge guard installation advice. RCtime Electrical | Charging, Solar and Electronics 12 11-20-2008 11:10 PM
8.1L in Winnebago Only Turns 3,000 RPM.... Capt Joe General Maintenance and Repair 8 02-24-2008 01:22 PM
Winnebago Class C Advice FlashG Winnebago Class C Motorhomes 11 01-04-2006 05:37 PM

» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Winnebago Industries or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 02:59 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.