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[GMCnet] tranmission modulator [message #317781] Thu, 18 May 2017 22:49 Go to next message
Brian Waddell is currently offline  Brian Waddell   United States
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Registered: March 2010
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My gmc motorhome does not stay in low gear very long...so...I cranked the screw inside the modulator ...that made it stay in low and second longer...I liked that so I did some more turning of the screw inside the modulator...Is there any detimental effects from doing this....Brian 77 ele 455 near winnipeg
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Re: [GMCnet] tranmission modulator [message #317789 is a reply to message #317781] Fri, 19 May 2017 08:25 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
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Probably not, but invoke Standard Transmission Info Source #1: Call or email Manny.

--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: [GMCnet] tranmission modulator [message #317792 is a reply to message #317789] Fri, 19 May 2017 09:06 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
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Registered: May 2010
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What turning that Allen screw does is put more tension on a spring that
balances against the force from the vacuum operated diaphram. The harder
you press down on the gas, the less vacuum you have available to move the
diaphram, and the spring becomes the dominant force. Shift point moves up,
and shift becomes a bit harsher. If you feel it is shifting too harsh, back
off the adjustment screw a bit. 1-2 up shift at light throttle occurs when
all is correct at 8 to 14 mph, give or take. 2-3 shift, 25 -35 or so. If
you mash the throttle, then it won't up shift until the governor forces the
shift.
Jim Hupy
Salem, Or
78 GMC ROYALE 403 w/a Manny tranny that shifts harshly when the throttle is
down. How I like it.

On May 19, 2017 6:26 AM, "Johnny Bridges via Gmclist" <
gmclist@list.gmcnet.org> wrote:

> Probably not, but invoke Standard Transmission Info Source #1: Call or
> email Manny.
>
> --johnny
> --
> 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> "I forgive them all, save those who hurt the dogs. They must answer to me
> in hell" - ol Andy, paraphrased
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
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Re: [GMCnet] tranmission modulator [message #318246 is a reply to message #317792] Tue, 30 May 2017 20:47 Go to previous messageGo to next message
Francois is currently offline  Francois   Canada
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Registered: October 2012
Location: Southern California
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I rebuilt my tränsmission. I have the 403 with the 4.10 final drive. After rebuild,I thought it was shifting fine at 6 mph and 23 mph, but with what was said, I am wondering. I put in the modulator that came with the kit. Not the same as OE. No adjustment screw. Do I need the original equipment modulator on there to adjust and make it shift a bit latér?
Re: [GMCnet] tranmission modulator [message #318251 is a reply to message #318246] Tue, 30 May 2017 21:59 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Registered: July 2006
Location: Belmont, CA
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Senior Member
The screw is down the tube where the vac hose is connected.
These adjustments are standard.
Please look again.

On Tue, May 30, 2017 at 6:47 PM, Sigmund Frankenfelter <
ziggy.frankenf@gmail.com> wrote:

> I rebuilt my tränsmission. I have the 403 with the 4.10 final drive.
> After rebuild,I thought it was shifting fine at 6 mph and 23 mph, but with
> what
> was said, I am wondering. I put in the modulator that came with the kit.
> Not the same as OE. No adjustment screw. Do I need the original equipment
> modulator on there to adjust and make it shift a bit latér?
>
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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] tranmission modulator [message #318261 is a reply to message #317781] Wed, 31 May 2017 08:18 Go to previous messageGo to next message
Larry is currently offline  Larry   United States
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Registered: January 2004
Location: Menomonie, WI
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Senior Member
Take a look at this....

http://www.gmcmhphotos.com/photos/transmission-install/p26806-img-0716.html

HTH


Larry Smile
78 Royale w/500 Caddy
Menomonie, WI.
Re: [GMCnet] tranmission modulator [message #318378 is a reply to message #318261] Fri, 02 June 2017 16:15 Go to previous message
Francois is currently offline  Francois   Canada
Messages: 161
Registered: October 2012
Location: Southern California
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Senior Member
Thanks so much. I didn't get that diagram
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