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Topic: Coasting Issue (Read 1088 times) previous topic - next topic

Re: Coasting Issue

Reply #25 –
That's better. Click on it twice
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Coasting Issue

Reply #26 –
Update on coasting problem.  I drove the coach to Mid Coast Engine and Transmission in Houston TX.  The first day we spent several hours driving with technician and his laptop connected to my round data port.  He and his supervisor determined that I was having an issue.  With the Retarder off and accelerator off, the transmission should remain in gear attained and coast.  However it instantly preselects 2 and starts to slow down and shift down as the engine speed allows until coming to a stop or adding pressure to accelerator to speed back up.  They agreed this was not normal.  They thought that they could fool the wire by putting a positive voltage on it.  I did not like this type of a fix and left for home to return the next day and asked for another solution.  The next day a few more hours of trying different things, each time we would take a trip of about 3 miles around a big square.  Got pretty good at City of Houston driving coach in traffic.  Each time the technician would make a recording and email it to Allison.  One of the things they suggested was that the Silverleaf was causing an issue.  So they moved their data input to the rectangular port above the round port and reconnected my Silverleaf so we could run their laptop and the Silverleaf at the same time.  However they reluctantly admitted that the Silverleaf was not affecting the operation.  Late in the second day Allison said that the retarder does not need to preselect a lower gear and suggested that they make the ECU disregard wires 119 and 163.  The allowed the coach to coast as it should when not applying the retarder and even when applying foot brake.  Now if I want to add engine braking along with Retarder, I must manually use the arrow on shifter to downshift.  Not a seamless operation as it was before this issue reared its ugly head, but workable and much easier driving in stop and go traffic.  It appears that Foretravel factory did something either physically or programming of ECU that allowed Preselect to come on upon engaging of Retarder.  A conversation with Foretravel appears to be in order.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Coasting Issue

Reply #27 –
As long as you are comfortable using the down arrow and D, you are good!

Many of us have had an Allison dealer change the pre-select gear.  I have mine changed to 5th.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Coasting Issue

Reply #28 –
Quote from: wolfe10 –
As long as you are comfortable using the down arrow and D, you are good!
Not a perfect fix, I intend to continue to pursue the correct fix.  I am ok with operating it this way for now.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Coasting Issue

Reply #29 –
Quote from: Herb Stark –
Update on coasting problem.

 With the Retarder off and accelerator off, the transmission should remain in gear attained and coast.  However it instantly preselects 2 and starts to slow down and shift down as the engine speed allows until coming to a stop or adding pressure to accelerator to speed back up. 

They agreed this was not normal. 

each time we would take a trip of about 3 miles around a big square.  Got pretty good at City of Houston driving coach in traffic. 

Late in the second day Allison said that the retarder does not need to preselect a lower gear 

It appears that Foretravel factory did something either physically or programming of ECU that allowed Preselect to come on upon engaging of Retarder. 

A conversation with Foretravel appears to be in order.

You don't have a coasting problem: You have a problem with your transmission downshifting when you don't think it should do so.

Why?  Because you want it to do so?

LIke most people, they're idiots.

That's how Lynn learned where the right wheels are located except it was in Birmingham Alabama and the GPS was leading him in circles. I am smart enough not to mention the shiny sidewalls.

No!  Really?

Why talk to Foretravel?  You need to talk to an Allison expert who has the tools to re-program the automatic down shift to a gear you're most likely to use.  Foretravel, bless their hearts, programmed yours for city traffic and city traffic speeds.  Gotta slow down?  The retarder engages and the transmission shifts from 3rd to 2nd.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Coasting Issue

Reply #30 –
If you get to east side of Houston, I have an Allison Guru
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Coasting Issue

Reply #31 –
Quote from: Rudy –
If you get to east side of Houston, I have an Allison Guru
Upon your recommendation I called Lewis Large (Allison Trash Truck) (Expert Transmission) He  came, worked three nights, and did all he could do.  Lewis then sent me to Mid Coast(Allison transmission service).  I went to Mid Coast on Lewis's recommendation.  What did I do wrong.  Do you have someone else who is an Allison Guru on the East side of Houston?  Lewis seemed very competent, with the right equipment to analyze the transmission.
.
Are my expectations wrong?  I do not expect it to try to downshift when I take my foot off the accelerator unless I have the retarder switch on and the joy stick pulled back.  With the retarder off and accelerator off,  I expect it to coast.  That is the way it has worked until two months ago.  That is the way my 2000 U320 worked, that is the way my 2007 Dynasty worked with a two speed engine brake.

Seriously, I am just trying to get my coach to work the way it did when I purchased it.  I am not angry with anybody, just trying to work through this.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Coasting Issue

Reply #32 –
Herb,

Have you had the Allison ECU out of the coach at any time during your trouble shooting.  I ask because when I had ours out for repairs (the dreaded snake eyes syndrome) I found a sticker on the back side indicating that a former owner had our trans reprogramed.  Just wondering if your ECU has anything like that.  See photo.

The funny thing is, on our coach since we have owned it, the "automatic downshift to 2nd gear" has never worked.  We have a exhaust brake rather than a retarder, but the transmission doesn't know that.  It is just supposed to get a signal from somewhere (?) to downshift when the "brake" is on.  However, I have always been happy that it doesn't work - I would rather decide for myself when I want it to downshift and make the gear change manually.  Different strokes...

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Coasting Issue

Reply #33 –
Quote from: Herb Stark –
Seriously, I am just trying to get my coach to work the way it did when I purchased it.  I am not angry with anybody, just trying to work through this.
You need the kind of Allison guy that can actually reprogram the electronics*.  All he needs to do is change a parameter or two and all will be back to normal.  How it got changed is not our problem.  This is one of those mysterious computer things that just "is."
If Rudy's Guru is that kind of guy, then that's the guy you need.

*Not all repair shops, even manufacturer's shops are created equal.  They each own a different sort of Allison franchise.  I imagine the shops that can reprogram the ECU are at the top of the heap, and therefore the most expensive franchise to own and operate.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Coasting Issue

Reply #34 –
Quote from: Chuck & Jeannie –
Herb,

Have you had the Allison ECU out of the coach at any time during your trouble shooting.  I ask because when I had ours out for repairs (the dreaded snake eyes syndrome) I found a sticker on the back side indicating that a former owner had our trans reprogramed.  Just wondering if your ECU has anything like that.  See photo.

The funny thing is, on our coach since we have owned it, the "automatic downshift to 2nd gear" has never worked.  We have a exhaust brake rather than a retarder, but the transmission doesn't know that.  It is just supposed to get a signal from somewhere (?) to downshift when the "brake" is on.  However, I have always been happy that it doesn't work - I would rather decide for myself when I want it to downshift and make the change manually.  Different strokes...


Lewis Large tried another Allison ECU, So did Mid Coast Transmission.  Allison told them that the Retarder does not require the downshift, but the engine brake does.

Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Coasting Issue

Reply #35 –
Quote from: Old Toolmaker –
You need the kind of Allison guy that can actually reprogram the electronics*.  All he needs to do is change a parameter or two and all will be back to normal.  How it got changed is not our problem.  This is one of those mysterious computer things that just "is."
If Rudy's Guru is that kind of guy, then that's the guy you need.

*Not all repair shops, even manufacturer's shops are created equal.  They each own a different sort of Allison franchise.  I imagine the shops that can reprogram the ECU are at the top of the heap, and therefore the most expensive franchise to own and operate.
.
Yep, Mid Coast was able to reprogram the ECU.  They were in constant contact with Allison, sending recordings of test drives back to Allison and getting responses from Allison for programming adjustments to make.  Allison recommended to program the ECU so that it disregarded the status of wires 119 and 163.  Allison said that manufacturers (Foretravel) sometimes make changes to programming or wires that is non standard.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Coasting Issue

Reply #36 –
Herb,

Your expectations (to be able to COAST) are reasonable.  Looking forward to the solution.

May be worth reaching out to John (Transmission Instruments

See if he has ever run into this or has any suggestions.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Coasting Issue

Reply #37 –
Quote from: wolfe10 –
Herb,

Your expectations (to be able to COAST) are reasonable.  Looking forward to the solution.

May be worth reaching out to John (Transmission Instruments

See if he has ever run into this or has any suggestions.
Thanks, I put him on my list to call.
Herb and Willie
Escapees 90802
2014 IH-45 Build 6581
2002 U320 40' AGDS Build 6021 Sold
1999 U320 36' No Slides Sold
2007 Monaco Dynasty Diamond IV Sold
2005 Discovery 39 Sold
1986 20' Wilderness TT,  Died a natural death after floods, etc.
Walldog's Journeys
And Willie Said

Re: Coasting Issue

Reply #38 –
As you have said it worked perfectly until 2 months ago. So something happened then. If the
number 11 wire got shorted out some where that would cause the symptoms you are talking
about.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Coasting Issue

Reply #39 –
I was recently told that some Cummins engines have both Jake Brake and retarder, they were included in some engine builds that FOT bought, so it could be that you have this and the dash wiring is simply not hooked up. However some abrasion on a wire could perhaps create the situation you describe, it would also explain why the ECU swap did nothing.
I think the only way to find it is a long and frustrating search of the harness looking for such wear and tear.
I would start in areas that were recently worked on, looking for an inadvertent crimp or similar.
Hope you find the fix.
1998 U295 36'
Build# 5358

SMILE!....it makes people wonder what you have been doing.
 

Re: Coasting Issue

Reply #40 –
The retarder has nothing to do with the Cummins. The shifting down is caused by the transmission
computer shifting down to the program gear when the # 11 wire is grounded. When I wired up the
#11 wire I wired it to a separate floor switch so any time that my foot is off the throttle I can push the
floor switch to get the transmission to shift down and it will shift down to 2nd gear as the revs dictate.
My transmission is programed for 2nd gear which is what I wanted and I was lucky when I put in the
Jake the engine and trans computers were already programed.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport