TEMPS: Downhill in a PT-42 Series 60/Allison

[erniecarpet@...]

In a message dated 6/17/2008 5:38:39 P.M. Central Standard Time, bumpersbird@... writes:

4th. and just rip up a hill

In my dreams~

Ernie Ekberg
83PT40
Livingston, Montana

---

Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.

[bumpersbird]

Cory,

Welcome to the club:}

I got to drive my 1995 PT-42. 5000 miles in three weeks last summer
in CO. WY. SD. lots of Hills and Mountains.

You need to read the Allison Operating Manuel on how to desend a
steep grade.

Hopefully you have some info on this in your Blue Box. OOPS!! Did you
get a Blue plastic box full of owners and operating manuels? Well if
not these guys can find answers to anything BB. If you need them I
have a set of blueprints for the PT-42's compliments of Wallace Craig.

Going uphill I use my control pad to change gears to keep the Series
60 at around 1800 RPM to keep it in the power band. If I let the
Allison do it I will loose speed and power going uphill. After a
while you'll know where she likes to run, and when to help her out.

GOING DOWNHILL!!!

This has happened to me and it is is the Allison Op Man.

If your going downhill in lets say second or third gear. Once you hit
your shift point, (2100 to 2200 RPM), it will go to the next gear.
Regardless of what gear you have choosen on the control pad.

Of course this happens when you do not want to be going downhill fast!

The way I have overcome this is by choosing what gear I want to
desend with on the control pad, 3rd. or 4th. apply high jake brake
setting and use the Chassie Brakes to keep her under the RPM shift
point. This is explained in the Operating Manual.

This not always easy to do and it can get away from you if you are
not paying close attention.

Also the jake brake looses effectivness at lower RPM, so you have to
get into the sweat spot. For me thats around 1500 to 1800. After 1800
I'm on the brakes to keep her from climbing up too high into the
shifting point/RPM range, but enough RPM to keep the Jake fully
working. Sometime your using more brakes than you would like but
there is no other option. That's why you never let her get ahead of
the road conditions.

I run the control pad with MODE OFF going downhill. She will run away
with me if it's in MODE ON. I have never gotten a satisfactory answer
on how Mode On is set up for my coach but after 20,000 miles it's
great on cruise at a steady speed, but if you need more shifting
leave it off. By the way if you run with the cruise on turn off the
jake brake. It will activate and fight the cruise control. At least
it does on my coach.

Kurt Horvath
95 PT-42 WLWB
Fayetteville TN

[Pete Masterson]

In slightly rolling hill country, I use the cruise control and set the jake to "low" ... it will keep the coach in a reasonable speed band. On more gentle slopes, the jake will slow down the coach by about 5 mph before the cruise control kicks in to accelerate. Probably uses more fuel in that situation. I generally turn off the cruise control in rolling hills as it's not very good at maintaining an even speed in that situation, since it doesn't anticipate the next up-slope, so I can do better by letting the coach gather a little extra speed at the bottom of a hill to let the momentum help with the next upgrade.

Kurt, what is this mode 1 and mode 2 you're talking about? I hadn't heard anything about it. (I'll have to go looking for my Allison manual -- I'm pretty sure I have one in the blue box somewhere.)

On my coach, when I'm under jake brake operation the up-shift doesn't occur until 2400 RPM. The engine book explains that "under power" the maximum RPM is 2100 but under no power, the engine is allowed to go to 2400 RPM. (I try to avoid letting it run up above 2100, as much as possible anyway.)

I note that when it's at or above 2100 RPM and I step on the throttle, then there's a big delay while the transmission up-shifts before the power comes back on. 

As you say, 1800 to 2000 RPM is a pretty good sweet spot for the jake brake.

Pete Masterson

'95 Blue Bird Wanderlodge WBDA 42

El Sobrante CA

"aeonix1@mac.com"

On Jun 17, 2008, at 2:35 PM, bumpersbird wrote:

<snip> By the way if you run with the cruise on turn off the 

jake brake. It will activate and fight the cruise control. At least 

it does on my coach.

[bumpersbird]

Pete,

On your Allison control pad or I should say I have, D,N,R on one side
on the other side I have one arrow up, one arrow down, and MODE.

Mode is either off or on. It is a preset program designated by the
builder as to how the transmission operates. The mode off is a
factory default setting.

In my case when in MODE ON the coach just runs mostly in 6th at
highway speeds and only down shifts once the engine has allready drop
under something like 1300 RPM. So she's already bogged down. It's
great on the flats.

With MODE OFF she tends to shift a bit too much in cruise. Hit that
overpass and she drops to 5th right now. Keeps the speed set on the
silver leaf exactly, and if it's a long haul uphill the RPM's stay up
and she'll drop to 4th. and just rip up a hill.

I would say in MODE OFF the is tranny working harder, and in MODE ON
the engine is trying to throw power at the tranny. I would like
something in the middle. I guess thats why I started hitting shift
buttons. If I'm cruising down the freeway and in MODE ON and in
cruise, if she doesn't shift befor loosing too many RPM I'll do it
for her.

The arrow keys let you shift gears up or down. Of course you have to
be in the correct RPM range befor she will change gears.

It seems as though my jake is sensitive even a small overpass will
set it off if it's in cruise. The motor spins up just in time for the
jake to cut in.

By the way it will do this going uphill to. Does anyone know why that
happens?

Kurt Horvath
95 PT-42 WLWB
Fayetteville TN




--- In WanderlodgeForum@yahoogroups.com, Pete Masterson
wrote:
>
> In slightly rolling hill country, I use the cruise control and set
> the jake to "low" ... it will keep the coach in a reasonable speed
> band. On more gentle slopes, the jake will slow down the coach by
> about 5 mph before the cruise control kicks in to accelerate.
> Probably uses more fuel in that situation. I generally turn off
the
> cruise control in rolling hills as it's not very good at
maintaining
> an even speed in that situation, since it doesn't anticipate the
next
> up-slope, so I can do better by letting the coach gather a little
> extra speed at the bottom of a hill to let the momentum help with
the
> next upgrade.
>
> Kurt, what is this mode 1 and mode 2 you're talking about? I
hadn't
> heard anything about it. (I'll have to go looking for my Allison
> manual -- I'm pretty sure I have one in the blue box somewhere.)
>
> On my coach, when I'm under jake brake operation the up-shift
doesn't
> occur until 2400 RPM. The engine book explains that "under power"
the
> maximum RPM is 2100 but under no power, the engine is allowed to
go
> to 2400 RPM. (I try to avoid letting it run up above 2100, as much
as
> possible anyway.)
>
> I note that when it's at or above 2100 RPM and I step on the
> throttle, then there's a big delay while the transmission up-
shifts
> before the power comes back on.
>
> As you say, 1800 to 2000 RPM is a pretty good sweet spot for the
jake
> brake.
>
> Pete Masterson
> '95 Blue Bird Wanderlodge WBDA 42
> El Sobrante CA
> aeonix1@...
>
>
>
> On Jun 17, 2008, at 2:35 PM, bumpersbird wrote:
> > <snip> By the way if you run with the cruise on turn off the
> > jake brake. It will activate and fight the cruise control. At
least
> > it does on my coach.
> >
>

[Pete Masterson]

I guess my coach is in MODE OFF -- I've always noticed that it shifts more than I'd shift if I were doing it myself. I do set it to hold a gear when it gets into a gear-hunting situation on an up grade. And I've used the up-down arrows on many occasions as conditions dictated.

I'll have to experiment with the MODE ON ... now that I reflect on it, I remember the MODE button -- it was one of those things I intended to review in the manual once I got around to it -- and I guess I never got around to it...

It sounds like MODE ON will make some of those relatively flat freeway stretches with the occasional overpass, etc. less shifty...

FWIW, I've never had the jake come on while going up hill. The Jake is fully integrated into the system (when it is enabled) so it comes on whenever the coach is decelerating. I guess you must be taking your foot off the throttle -- that would trigger the Jake...

I do get the jake kicking in (often unnecessarily) while in cruise while going down a very slight decline. Depending on the terrain, that's when I'll often disable the jake...

Pete Masterson

'95 Blue Bird Wanderlodge WBDA 42

El Sobrante CA

"aeonix1@mac.com"

On Jun 17, 2008, at 4:38 PM, bumpersbird wrote:

Pete,

On your Allison control pad or I should say I have, D,N,R on one side 

on the other side I have one arrow up, one arrow down, and MODE.

Mode is either off or on. It is a preset program designated by the 

builder as to how the transmission operates. The mode off is a 

factory default setting.

In my case when in MODE ON the coach just runs mostly in 6th at 

highway speeds and only down shifts once the engine has allready drop 

under something like 1300 RPM. So she's already bogged down. It's  

great on the flats. 

With MODE OFF she tends to shift a bit too much in cruise. Hit that 

overpass and she drops to 5th right now. Keeps the speed set on the 

silver leaf exactly, and if it's a long haul uphill the RPM's stay up 

and she'll drop to 4th. and just rip up a hill.

I would say in MODE OFF the is tranny working harder, and in MODE ON 

the engine is trying to throw power at the tranny. I would like 

something in the middle. I guess thats why I started hitting shift 

buttons. If I'm cruising down the freeway and in MODE ON and in 

cruise, if she doesn't shift befor loosing too many RPM I'll do it 

for her.

The arrow keys let you shift gears up or down. Of course you have to 

be in the correct RPM range befor she will change gears.

It seems as though my jake is sensitive even a small overpass will 

set it off if it's in cruise. The motor spins up just in time for the 

jake to cut in.

By the way it will do this going uphill to. Does anyone know why that 

happens?

[bumpersbird]

Ernie,

That was pre $3 bucks a gallon days.

Now I'm trying to see how far a gallon will get me. Three weeks ago
on 65 S to B'Ham AL for a 48 mile track. Silver Leaf was registering
8.8 MPG @ 59 MPH. Overall trip was 247.7 miles avg. consumption @ 7.1
MPG.

No I can't verify by old method. I haven't fueled the coach for a
while.

Yea, Yea, I know TALK TO THE VMSpc! :}

Kurt Horvath
95 PT-42 WLWB
10AC
--- In WanderlodgeForum@yahoogroups.com, erniecarpet@... wrote:
>
>
> In a message dated 6/17/2008 5:38:39 P.M. Central Standard Time,
> bumpersbird@... writes:
>
> 4th. and just rip up a hill
>
>
> In my dreams~
>
> Ernie Ekberg
> 83PT40
> Livingston, Montana
>
>
>
>
> **************Gas prices getting you down? Search AOL Autos for
> fuel-efficient used cars. (http://autos.aol.com/used?
ncid=aolaut00050000000007)
>

[David Brady]

My coach did "gear-hunt" on grades but the condition was

remedied when I had my transmission, Allison 4060HD,

reflashed. I'm currently running software version:

0C00 ABF 008N.



David Brady

'02 LXi, NC





Pete Masterson wrote:

I guess my coach is in MODE OFF -- I've always noticed that it
shifts more than I'd shift if I were doing it myself. I do set it to
hold a gear when it gets into a gear-hunting situation on an up grade.
And I've used the up-down arrows on many occasions as conditions
dictated.