Downshift Solenoid

[heinz wittenbecher]

Dave,
be sure that the downshift switch on the gas pedal linkage is working
correctly.

Easy to check with a light.

I just replaced mine.

Heinz

>Our '76 Royale (transmode) will not downshift above 34 MPH without using
>the selector lever, irresprective of foot feed pressure.
>
>The maintenance manual (X-7525B) says it can be removed without removing
>the tranny, but shows the solenoid attached to the control valve.
>
>Does the pan have to be dropped to get to the solenoid?
>
>Also, how do I make sure I order the right part, specify '75 toro?
>
>I'll appreciate advice from those who know.
>
>
> ___________
>Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
> Santa Barbara, CA *0-------OO--* (our hobby)
>
>
>

 

[dave lowry]

Our '76 Royale (transmode) will not downshift above 34 MPH without using
the selector lever, irresprective of foot feed pressure.

The maintenance manual (X-7525B) says it can be removed without removing
the tranny, but shows the solenoid attached to the control valve.

Does the pan have to be dropped to get to the solenoid?

Also, how do I make sure I order the right part, specify '75 toro?

I'll appreciate advice from those who know.

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)

 

[dave lowry]

Thanks, Heinz

The OEM switch as well as the supplemental one that Zak uses have both been
tested. In addition, a test light at the tranny confirms that 12v. is
getting that far.

I'm pretty sure my problem is with the solenoid, but need to know what's
involved in replacing it.

I figured it would be a good time to ask the question since it's relatively
quiet.

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)

 

[richard guthart]

Dave,

I have not tried it, but based on the GMC manuals you can access the solenoid
from the underside of the tranny, but first you must get inside the pan by
removing it and draining the fluid.

Richard

> I'm pretty sure my problem is with the solenoid, but need to know what's
> involved in replacing it.

 

[travis martin]

Before you go to the trouble to drop the pan, I'd be very sure that the
problem is there. The downshift solenoid is relatively small, about the size
of an ice cube, but will make a distinct click when energized. All that
happens is that a small fluid port is uncovered.

Try, before dropping the pan, running a 12Volt test light off of the hot
wire...big terminal on the starter would be convenient...and touching the
business end of it to the solenoid terminal. Assuming it is relatively
quiet, you should hear the click and the test light should light, though
probably dimly since it is in series with the solenoid. If it does, you
likely don't have a solenoid problem. It's either the 12 Volt line to the
solenoid through the kickdown switch (I understand you've already checked
that)or perhaps a hydraulic problem in the valve body. But I'd want to know
before I dropped the pan if it were me.

Travis

- -----Original Message-----
From: Richard Guthart
To: gmcmotorhome
Date: Tuesday, June 15, 1999 7:01 PM
Subject: Re: GMC: Downshift Solenoid

>Dave,
>
>I have not tried it, but based on the GMC manuals you can access the
solenoid
>from the underside of the tranny, but first you must get inside the pan by
>removing it and draining the fluid.
>
>Richard
>
>> I'm pretty sure my problem is with the solenoid, but need to know what's
>> involved in replacing it.
>
>
>

 

[travis martin]

Sure...do it from underneath; it's not real loud and you'll need to be close
by to hear it. I'm not sure you'd hear it from above.

Travis

- -----Original Message-----
From: Dave Lowry
To: gmcmotorhome
Date: Wednesday, June 16, 1999 8:29 PM
Subject: GMC: Downshift Solenoid

>Thanks Richard and Travis.
>
>I've tried listening from inside with the engine cover open, but have not
>tried a direct hot wire from underneath. I'll be sure that's tried before
>dropping the pan.
>
>
> ___________
>Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
> Santa Barbara, CA *0-------OO--* (our hobby)
>
>
>

 

[dave lowry]

Thanks Richard and Travis.

I've tried listening from inside with the engine cover open, but have not
tried a direct hot wire from underneath. I'll be sure that's tried before
dropping the pan.

___________
Dave (& Dege), '76 Royale /_][__] [_] | "SR JAMES"
Santa Barbara, CA *0-------OO--* (our hobby)