Home » Public Forums » GMCnet » Kickdown on the transmission (When should it downshift?)
Kickdown on the transmission [message #281085] |
Tue, 30 June 2015 14:10 |
Dan
Messages: 99 Registered: August 2014 Location: Allentown, NJ
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Just got back from a successful trip to the foothills of the NJ Skylands. On the way up the GPS took me on a route that had me making a sharp right turn onto a steep hill. I was scared for a second that without any momentum I would not make it up. I was just creeping at a 5 or 10 mph with my foot floored. I shifted the the gear selector into the lowest setting and it went down to first and the coach picked up speed and climbed the hill.
How should a coach react in a situation like that. I assumed that will my foot floored I'd hit a kick down switch and it would go into first. Thanks for the advice.
Dan DeLuca
1978 Eleganza II (http://imgur.com/gallery/YFHhK)
Parked at Evil Monkey Farm in
Allentown, New Jersey
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Re: Kickdown on the transmission [message #281087 is a reply to message #281085] |
Tue, 30 June 2015 14:36 |
jknezek
Messages: 1057 Registered: December 2007
Karma: 5
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If you have a transmission rebuilt by Manny Travao it will not have a kickdown. I generally manually shift down on uphill stretches when necessary. If I'm in 3rd and drop to 38mph, I shift to second. If I drop below 18, I drop to first gear. However, this only applies when you have a continuous gear. Around town, slowing in to traffic lights or just general traffic where you take your foot off the gas will have your transmission automatically shift.
Even if you have a kickdown, it really only shifts from 3rd to second and a half from what I understand. Someone more technical will give you a better explanation, but it's not the same as a true downshift. Also, instead of using MPH like I use, if you have a vacuum gauge or a tachometer I believe you could use those to decide your manual downshift points. I have neither, so MPH works for me.
Thanks,
Jeremy Knezek
1976 Glenbrook
Birmingham, AL
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Re: Kickdown on the transmission [message #281093 is a reply to message #281091] |
Tue, 30 June 2015 15:12 |
Dan
Messages: 99 Registered: August 2014 Location: Allentown, NJ
Karma: 0
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Sean,
We joined the travelers, but have not gotten to a rally yet. My wife works the weekends. Hope to meet up with you one day there. We stayed at Mountain View by Milford. Ancient place, with kinda spooky ruins everywhere. We pretty much had the run of it to ourselves. On the way back I headed towards the Delaware and took the valley back. Still plenty of tight curves but less hills. New Jersey doesn't have anything too tall, but some roads just go straight up over the hills and that make thing more difficult then they should be.
I don't mind using the stalk to downshift, I guess now I know.
Dan
Dan DeLuca
1978 Eleganza II (http://imgur.com/gallery/YFHhK)
Parked at Evil Monkey Farm in
Allentown, New Jersey
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Re: Kickdown on the transmission [message #281095 is a reply to message #281085] |
Tue, 30 June 2015 15:36 |
Bob de Kruyff
Messages: 4260 Registered: January 2004 Location: Chandler, AZ
Karma: 1
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Dan wrote on Tue, 30 June 2015 13:10Just got back from a successful trip to the foothills of the NJ Skylands. On the way up the GPS took me on a route that had me making a sharp right turn onto a steep hill. I was scared for a second that without any momentum I would not make it up. I was just creeping at a 5 or 10 mph with my foot floored. I shifted the the gear selector into the lowest setting and it went down to first and the coach picked up speed and climbed the hill.
How should a coach react in a situation like that. I assumed that will my foot floored I'd hit a kick down switch and it would go into first. Thanks for the advice.
If your kickdown switch and solenoid are operating, the transmission should downshift at almost any speed below the maximum upshift point. In otherwords, if you are in 3rd, you should get 2 cnd at a speed below 65 if you floor it. The same goes for 1st gear at lower speeds--I know mine will go into first below about 40 mph. There is a lot of controversy about disabling the switch--I personally think that is a mistake since you don't always have time to manually downshift. I do agree that under hard pulls up hill that it is better to manually downshift using the shift lever, but that is a different situation. Either your switch is misadjusted, your pedal rod is bent, or the system has been disabled by a P.O. My 78 has run for 145,000 miles with the kickdown working and it doesn't seem to have hurt anything. I find it very handy and safer when you need an immediate downshift.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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Re: Kickdown on the transmission [message #281116 is a reply to message #281095] |
Tue, 30 June 2015 18:35 |
George Beckman
Messages: 1085 Registered: October 2008 Location: Colfax, CA
Karma: 11
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Bob de Kruyff wrote on Tue, 30 June 2015 13:36
If your kickdown switch and solenoid are operating, the transmission should downshift at almost any speed below the maximum upshift point. In otherwords, if you are in 3rd, you should get 2 cnd at a speed below 65 if you floor it. The same goes for 1st gear at lower speeds--I know mine will go into first below about 40 mph. There is a lot of controversy about disabling the switch--I personally think that is a mistake since you don't always have time to manually downshift. I do agree that under hard pulls up hill that it is better to manually downshift using the shift lever, but that is a different situation. Either your switch is misadjusted, your pedal rod is bent, or the system has been disabled by a P.O. My 78 has run for 145,000 miles with the kickdown working and it doesn't seem to have hurt anything. I find it very handy and safer when you need an immediate downshift.
I don't know but am guessing as to the why of using the shift lever. Manny says that when the selector is in Second the pressure in the transmission is doubled. He likes this to make sure there is lots of pressure to keep the clutches and bands tight. I am guessing that the kick down puts it in 2nd ratio but it does not have the advantage of the higher pressure.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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Re: Kickdown on the transmission [message #281120 is a reply to message #281085] |
Tue, 30 June 2015 18:54 |
George Beckman
Messages: 1085 Registered: October 2008 Location: Colfax, CA
Karma: 11
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Dan wrote on Tue, 30 June 2015 12:10Just got back from a successful trip to the foothills of the NJ Skylands. On the way up the GPS took me on a route that had me making a sharp right turn onto a steep hill. I was scared for a second that without any momentum I would not make it up. I was just creeping at a 5 or 10 mph with my foot floored.
Dan,
I was re-thinking your post. I would think that at 10 mph, the governor would have already have shifted, at least to second. My coach goes to Low at about 5 mph.
I bring this up because I drove my original transmission in 3rd gear for almost two years before the transmission went (further) south.It actually did surprisingly well. I never imagined. I knew it seemed sluggish but it was my first 3.07 (stock) gears. The stock torque converters have such a high stall that starting is sloppy, engine speed wise, anyway. The transmission made a different whine twice as I accelerated and perhaps that was oil changing direction as it "tried" to shift. The selector would shift it.
I am having governor troubles right now and I only did a very short test run and realized it was starting in 3rd.
The best test is to start off from a stop and after it is moving perhaps 2 mph move the selector to Low and if it wasn't in Low you will feel and hear the difference.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
[Updated on: Tue, 30 June 2015 18:56] Report message to a moderator
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Re: [GMCnet] Kickdown on the transmission [message #281129 is a reply to message #281085] |
Tue, 30 June 2015 19:51 |
Ken Henderson
Messages: 8726 Registered: March 2004 Location: Americus, GA
Karma: 9
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Dan,
The first thing you need to do is reach up above the accelerator pedal and
find the 5/16" diameter rod sticking out the side of the switch assembly
there. Push the rod toward the accelerator arm -- it will slide with some
clicking. The next time you press the accelerator to the floor, the switch
will automatically adjust itself. That MAY fix your downshift ("passing
gear") problem.
If that doesn't do it, check at the lower right rear of the transmission,
beside the modulator, for a two-contact screw-in switch. Be sure that's
connected -- there will be only one wire (to the center terminal) -- the
second contact is for a switch-pitch transmission, which I assume you don't
have.
After getting the passing gear working, try not to use it. Manual
downshift is much easier on the transmission.
HTH,
Ken H.
On Tue, Jun 30, 2015 at 3:10 PM, Daniel DeLuca wrote:
> Just got back from a successful trip to the foothills of the NJ Skylands.
> On the way up the GPS took me on a route that had me making a sharp right
> turn onto a steep hill. I was scared for a second that without any
> momentum I would not make it up. I was just creeping at a 5 or 10 mph with
> my
> foot floored. I shifted the the gear selector into the lowest setting and
> it went down to first and the coach picked up speed and climbed the hill.
>
>
> How should a coach react in a situation like that. I assumed that will my
> foot floored I'd hit a kick down switch and it would go into first. Thanks
> for the advice.
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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Re: [GMCnet] Kickdown on the transmission [message #281136 is a reply to message #281129] |
Tue, 30 June 2015 20:59 |
Dan
Messages: 99 Registered: August 2014 Location: Allentown, NJ
Karma: 0
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I am pretty certain I have all three gears, I can feel the transmission run through the cogs if I am heavy with the accelerator peddle. The situation was a slow right turn, I think the transmission was in second and stayed there. Everything happened pretty fast, but it basically as I headed up the hill I got the bad feeling that the motorhome was slowing down too quickly. Floored it, no improvement, then I shifted with the stalk.
Next time I have it out I will play around to see if the kick down works, but next time I run into that situation I will not hesitate to use the gear selector to get me up the hill.
Dan DeLuca
1978 Eleganza II (http://imgur.com/gallery/YFHhK)
Parked at Evil Monkey Farm in
Allentown, New Jersey
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Re: Kickdown on the transmission [message #281154 is a reply to message #281085] |
Wed, 01 July 2015 01:09 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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You probably have a very common problem. I have fixed at least 10 of these for people on GMCs. Stick your head under the dash and look at the kick down switch. Push the accelerator all the way down and observe the switch. I'll bet it is not transferring the switch. If this is your problem, simply pull up on the gas pedal and bend it slightly back into shape. This is a one minute no tool fix.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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