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


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-10-2017, 06:45 PM   #1
Junior Member
 
Join Date: Mar 2017
Location: west chester
Posts: 1
down shifting

I'm hoping someone can answer this:
When driving our Jayco Precept 31UL and cresting a hill the unit downshifts a couple of gears and the RPM jumps up to 4-5 thousand RPMS. Is this normal - no one seems to have an answer - I talked to Ford and they couldn't answer it either. They told me to bring it in and they would drive it - and if it happened they could address it. It doesn't happen all the time, but would love to get this fixed, if it is not normal.
papa&punkie is offline   Reply With Quote
Old 12-10-2017, 07:22 PM   #2
Senior Member
 
WinnieView's Avatar
 
Join Date: Nov 2017
Location: anytown
Posts: 1,751
Sounds like it has some sort of engine tune or feature which allows the gas engine to behave more like a diesel with an exhaust brake.

One rule of thumb when driving is whichever gear is used to get up the hill should be the same gear used to get down.
WinnieView is offline   Reply With Quote
Old 12-10-2017, 09:15 PM   #3
Member
 
Sadie's Avatar
 
Join Date: Dec 2016
Location: Calgary
Posts: 65
Check your Ford manual page 34 (on my manual) its called: Forced Downshifts.
If you drive with the cruise control on it will downshift to very high rpm's if you go downhill. Keep in mind that it is doing this to keep the speed programmed. Forced Downshifts is on also if the tow/haul feature on or off. It is a feature of the transmission. There are many posts in the internet about that. google: ford Forced Downshifts motorhome
Sadie is offline   Reply With Quote
Old 12-10-2017, 09:39 PM   #4
Member
 
OutCole'd's Avatar
 
Join Date: Dec 2016
Location: Las Vegas
Posts: 61
Mine does this also, i’m sure they all do. Drives me crazy seeing the RPM’s over 4k screamimg like that.
OutCole'd is offline   Reply With Quote
Old 12-10-2017, 11:56 PM   #5
Senior Member
 
Arniesports60's Avatar
 
Join Date: Mar 2015
Location: Prescott Valley
Posts: 179
Area you using the Tow/haul mode when going thru hills?
Arniesports60 is offline   Reply With Quote
Old 12-11-2017, 07:13 AM   #6
Senior Member
 
The Logans's Avatar
 
Join Date: May 2014
Location: North Western West Virginia
Posts: 671
Tow haul doesn't effect the forced downshift. It's to save the brakes on long steep downgrades... the V10 was designed for high RPM's, don't worry about it.

We used tow haul on the 5 speed tranny in the old motorhome, but we've never had to use it with the new motorhome, as it has a 6 speed tranny.
__________________
The Logan's
2018 Jayco Alante 31v
Me, Dear Wife,
2 Bluetick Hounds
1 Newfoundland
1 Newfoundland / Black Lab Mix
1 Cairn Terrier
The Logans is offline   Reply With Quote
Old 12-11-2017, 12:03 PM   #7
Junior Member
 
Join Date: Sep 2017
Location: Highland
Posts: 23
I looked at some other forums on RV towing especially gas vs diesel posts. It seams the Ford V10 is made to run comfortably above 4000 rpm and can run at 5000 rpm when climbing with a load. You might check out those resources. I found them helpful.
mountaineyedoc is offline   Reply With Quote
Old 12-11-2017, 02:22 PM   #8
Senior Member
 
Vicr's Avatar
 
Join Date: Apr 2016
Location: Fortuna Foothills
Posts: 1,862
We drive mountain passes quite frequently and there is a workaround for this. I keep my 35S in tow haul mode while ascending the grade. As we descend and the transmission drop gears I just take it out of tow haul mode and it will upshift right away.
Vicr is offline   Reply With Quote
Old 12-11-2017, 04:09 PM   #9
Senior Member
 
Join Date: Sep 2013
Location: Wentzville
Posts: 272
Quote:
Originally Posted by Vicr View Post
We drive mountain passes quite frequently and there is a workaround for this. I keep my 35S in tow haul mode while ascending the grade. As we descend and the transmission drop gears I just take it out of tow haul mode and it will upshift right away.
I had posted on this subject a while back. 4000 rpm is unnerving, is good to hear that it is ok. This tow haul workaround is something I’ll definitely be experimenting with the next time I’m in the mountains. I gather the V10 has electronic rev limiting. Is the limit 4000 rpm? I can’t recall whether or not i’ve seen anything higher than that. Would explain why the tach shows no red line, I suppose.
chasfenwick is offline   Reply With Quote
Old 12-11-2017, 04:49 PM   #10
Senior Member
 
Join Date: Mar 2015
Location: Odessa
Posts: 409
5 star tuning

Many people are unhappy with the V 10 engine and transmission combination - I hear that 5 Star Tuning can make it much better ( no personal experience )
__________________

Les & Sandy
2016 Seneca HJ - Scangauge D - Truma Comfort
560 watts solar - Blue Sky 3024iL -IPN ProRemote - Trojan T-105RE
Good Sam Life Member - FMCA Member - Passport America
Les7h is offline   Reply With Quote
Old 12-11-2017, 09:53 PM   #11
Senior Member
 
Join Date: Sep 2013
Location: Wentzville
Posts: 272
Quote:
Originally Posted by Les7h View Post
Many people are unhappy with the V 10 engine and transmission combination - I hear that 5 Star Tuning can make it much better ( no personal experience )
There seems to be a question about whether the 5 Star Tuning makes sense with the newer 6 speed transmission.
chasfenwick is offline   Reply With Quote
Old 12-11-2017, 10:19 PM   #12
Senior Member
 
Vicr's Avatar
 
Join Date: Apr 2016
Location: Fortuna Foothills
Posts: 1,862
Quote:
Originally Posted by Les7h View Post
Many people are unhappy with the V 10 engine and transmission combination - I hear that 5 Star Tuning can make it much better ( no personal experience )
The five star tune is for 2015’s and earlier with the 5 speed transmission. The 2016 and newer with the 6 speed works very well. I live in the west where we have real mountains and the engine/trans combo is a pleasure to drive.
Vicr is offline   Reply With Quote
Old 12-12-2017, 11:42 AM   #13
Senior Member
 
hawkster's Avatar
 
Join Date: Sep 2015
Location: frankfort
Posts: 392
Recently we took our 2016 31ul with 6 speed over one 11k foot pass and two over 8k foot passes. The six speed shifts down readily with a touch of the brake. I had no problems going down Monarch Pass in Colorado using very little brake and letting the tranny do it's thing. The v10 sings a little at higher rpm but that's the nature of the beast.
__________________
2016 Jayco Precept 31 ul
2016 Jeep Grand Cherokee toad

hawkster is offline   Reply With Quote
Old 12-12-2017, 11:56 AM   #14
Senior Member
 
Join Date: Jun 2015
Location: --
Posts: 2,392
5 star does improve the V10 in most ways, particularly the ones w/ the 5spd.
__________________
2023 Ford F-150 XLT SCREW 3.5EB (Max Tow Pkg., Black Appearance Pkg., Bed Utility Pkg.)
1727 Payload / 4150 RAWR

On the sidelines taking it all in.


Jopopsy is offline   Reply With Quote
Old 12-12-2017, 02:05 PM   #15
Senior Member
 
The Logans's Avatar
 
Join Date: May 2014
Location: North Western West Virginia
Posts: 671
When we looked into 5 Star, I checked with Ford before we bought... The dealership checked with the warranty center in Michigan, and were told that if any power-train component fails with 5 Star (or any other similar device) installed, the warranty would not be honored.

The service manager told me that the recording component of the engine control computer would show if any unapproved device had changed the factory shift points.

So, we didn't buy it.
__________________
The Logan's
2018 Jayco Alante 31v
Me, Dear Wife,
2 Bluetick Hounds
1 Newfoundland
1 Newfoundland / Black Lab Mix
1 Cairn Terrier
The Logans is offline   Reply With Quote
Old 12-12-2017, 02:08 PM   #16
Senior Member
 
Vicr's Avatar
 
Join Date: Apr 2016
Location: Fortuna Foothills
Posts: 1,862
Quote:
Originally Posted by Les7h View Post
Many people are unhappy with the V 10 engine and transmission combination - I hear that 5 Star Tuning can make it much better ( no personal experience )

Your 2016 should have the 6 speed. The 5 Star Tune does very little for the 6 speed.
Vicr is offline   Reply With Quote
Old 12-12-2017, 08:04 PM   #17
Senior Member
 
Join Date: Sep 2017
Location: midwest
Posts: 1,211
Most vehicle have had the redline removed from the tach.. maybe the stick shifted sports cars still have them? The computers now are so advanced with timing, fuel, air, exhaust and rev limits that they will shut off fuel if you force the RPMs high in a manual gear situation...


So put it in 1st and give it gas when it hits rev limiter it will stop delivering fuel to the engine... same with going down hill, if you try and downshift to a gear lower than the available RPM's it won't allow you to do it.. you have to brake to get the speed down and then it will downshift... at least that is how it works on mine.... and I bet fords as well..


When you change the shift points with an aftermarket product you could change the rev limiters out of OEM specifications causing engine damage, that is why ford/gm and others won't honor the warranty... This really started back in the mid 2000 with diesels.. people chipped them and took the motors out of OEM spec...


which is why many of these products are warranty breakers...
curver900 is offline   Reply With Quote
Old 12-13-2017, 07:24 AM   #18
Senior Member
 
hawkster's Avatar
 
Join Date: Sep 2015
Location: frankfort
Posts: 392
I can understand the mfg. When I worked for a printer company, some people complained about printer function or print quality. Upon my visit, many times I could see they refilled their toner cartridge with cheap toner causing the problem. Our company made it's own toner, tested in all temp and humidity and even at altitude and extreme storage conditions. Guess what, we don't test someone's cheap toner or guarantee it.
__________________
2016 Jayco Precept 31 ul
2016 Jeep Grand Cherokee toad

hawkster is offline   Reply With Quote
Old 12-13-2017, 07:03 PM   #19
Member
 
FlaBound's Avatar
 
Join Date: Jun 2016
Location: The Villages
Posts: 67
Quote:
Originally Posted by hawkster View Post
Recently we took our 2016 31ul with 6 speed over one 11k foot pass and two over 8k foot passes. The six speed shifts down readily with a touch of the brake. I had no problems going down Monarch Pass in Colorado using very little brake and letting the tranny do it's thing. The v10 sings a little at higher rpm but that's the nature of the beast.
As someone who has not yet tackled peaks of that height, your post is encouraging. Where you towing your jeep at the time?
__________________
2017 Precept 31UL
Chevy Equinox
SMI Stay and Play Braking system
Roadmaster Falcon Tow bar
Henderson rear trac bar
Safe-T Plus
FlaBound is offline   Reply With Quote
Old 12-13-2017, 07:41 PM   #20
Senior Member
 
hawkster's Avatar
 
Join Date: Sep 2015
Location: frankfort
Posts: 392
On the 11k pass I disconnected Jeep before going over. Glad I did. On 8k peaks did pull Jeep. It was ok but a lot of revs.
__________________
2016 Jayco Precept 31 ul
2016 Jeep Grand Cherokee toad

hawkster is offline   Reply With Quote
Reply

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


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

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


All times are GMT -6. The time now is 09:29 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright 2002-2016 Social Knowledge, LLC All Rights Reserved.