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

[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