Re: can someone explain kickdown?
[Re: 383man]
#356987
06/25/09 07:21 PM
06/25/09 07:21 PM
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Joined: Jan 2003
Posts: 1,756 London, England
Gavin
top fuel
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top fuel
Joined: Jan 2003
Posts: 1,756
London, England
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Quote:
Some people call it kickdown rod and some call it throttle pressure rod. Dont matter what you call it as it actually controlls what they call "throttle pressure" in the trans and since the throttle pressure is also sent to the pressure regulator it has some control over line pressure also. To put is in simple terms the rod moves as you step on the gas and the more it moves the more throttle pressure is built up inside the trans. As you give it more throttle pressure it will raise the shift points and vice versa. It works like this.....the trans has shift valves in it that will move from side to side to control upshifts by sending fluid to the right clutch pack or band to make it shift. Now it is an automatic trans as it shifts automaticly. It does that by having the trans pump create line pressure that is sent to a valve that regulates pressure by the output shaft speed called govenor pressure and it also has another pressure called throttle pressure that is controlled by the throttle valve in the trans that is connected to the trans throttle linkage (kickdown). The trans basically shifts by having govenor and throttle pressures work on both sides of the shift valves. Govenor pressure is on one side of the shift valve trying to push the valve over to one side as speed increases to make the trans shift. The other side of the shift valve has throttle pressure that raises as the gas pedal is pushed. When you go fast enough that the gov press overcomes the throttle press it moves the shift valve over shifting the trans. Now if you step on the gas a very small amount the throttle press is low and it wont take much speed to shift the trans. But when you push the gas pedal down far the throttle press is higher and you need more road speed to get the gov press high enough to overcome the throttle press to shift. Thats why if you hit the gas hard the trans shifts at a much faster speed. Now when driving along at say 30 mph in third gear (727 trans) if you floor it the throttle pressure goes very high and it will overcome gov press and push the shift valve the other direction and cause the trans to downshift. Hence the term kickdown came about as it will cause the trans to kickdown to the next lower gear. Make sense ? Ron
good explanation, I learnt something new from that thanks
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Re: can someone explain kickdown?
[Re: Dougsmopars]
#356989
06/25/09 08:14 PM
06/25/09 08:14 PM
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Joined: Sep 2007
Posts: 5,037 hi
sharpie
OP
Moparts Linguist
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OP
Moparts Linguist
Joined: Sep 2007
Posts: 5,037
hi
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Ron, BigD, others, thanks! I kind of understand. I don't have a three-piece kickdown because I have a 5.9L Magnum (which doesn't use the same throttle/kickdown bracket as the LA engine), so I am using the Lokar cable. Basically, I had adjusted it before so that the throttle pressure lever is almost all the way back at WOT.
So with that starting point, can anyone suggest where to adjust it from there? I am fine on the road, as it's shifting from 1-2 at 2000RPM and 2/3 at 2400RPM (give or take a few. My problem comes on the highway when I throttle it, I don't get it to kick down to first, and when I let off the throttle after passing (in second), I can't get it to upshift back to 3rd.
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Re: can someone explain kickdown?
[Re: sharpie]
#356990
06/26/09 02:21 PM
06/26/09 02:21 PM
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Joined: Nov 2004
Posts: 1,601 Hatfield,Pa.
bigD
top fuel
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top fuel
Joined: Nov 2004
Posts: 1,601
Hatfield,Pa.
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Shapie,PM Kunkle . He sould be able to get you headed in the right direction,very knowledgeable about TFs and their quirks,D.
2015 Chrysler200s,2008 Charger R/T R&T,1999 Dakota R/T,1999 Viper ACR,1968 Charger R/T.
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Re: can someone explain kickdown?
[Re: John_Kunkel]
#356993
06/26/09 06:38 PM
06/26/09 06:38 PM
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Joined: Aug 2003
Posts: 973 South Texas
badchallenger
Fluff Flipper
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Fluff Flipper
Joined: Aug 2003
Posts: 973
South Texas
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Dont want to hijack the post just one question. If you have the stock linkage how do you set it correctly ? Do you set it from the idle position full throttle position or what and how. Thanks! Dave
Last edited by badchallenger; 06/26/09 06:42 PM.
U.S. Navy Sea Bees (Retired now)
U.S. Army Civil Service NDT
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Re: can someone explain kickdown?
[Re: sharpie]
#356995
06/26/09 08:47 PM
06/26/09 08:47 PM
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Joined: Apr 2007
Posts: 807 Toronto, Canada
dirtybee
super stock
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super stock
Joined: Apr 2007
Posts: 807
Toronto, Canada
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Quote:
Ah, sounds good. I kind of understand. Right now, a major problem with mine is that the trans cooler lines might (or might not, I'm not positive) be preventing the throttle pressure lever from going all the way back.
thats not good, the most important thing is that the lever on the trans is all the way back at full throttle. the added line pressure holds the clutch packs harder keeping them from slipping and wearing prematurely. you can play around with the ratios to taylor your shift points as long as the trans lever is full back at wot
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Re: can someone explain kickdown?
[Re: badchallenger]
#356996
06/27/09 07:44 AM
06/27/09 07:44 AM
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Joined: Jan 2007
Posts: 535 Charlotte, NC
Kowal
mopar
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mopar
Joined: Jan 2007
Posts: 535
Charlotte, NC
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Quote:
Dont want to hijack the post just one question. If you have the stock linkage how do you set it correctly ? Do you set it from the idle position full throttle position or what and how. Thanks! Dave
See attached. First you adjust the from the lever on the trans to the pivot point at the rear, top, of the engine, then you do the threaded rod. Finally, after you have it done, check for interference at WOT. Fine adjustment is as mentioned above...lengthen the rod to delay the shifts. (be careful of WOT interference)
'69 Hemi Charger 500, ‘70 U code Challenger R/T (These and a bunch others at www.dkowal426.com) P.J. O'Rouke: "The old car ran perfectly, right up until it didn't."
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Re: can someone explain kickdown?
[Re: 69L78Nova]
#356999
06/27/09 02:37 PM
06/27/09 02:37 PM
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Joined: Oct 2003
Posts: 1,249 Las Vegas
JeffC
pro stock
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pro stock
Joined: Oct 2003
Posts: 1,249
Las Vegas
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Quote:
Its not a kickdown. Thats Chevy nonsense talk. It controls line pressure, shift points, shift firmness, and downshifting
Hey no need to bring chevy into this mess, the equivalent part on a chevy would be a "throttle valve cable".
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Re: can someone explain kickdown?
[Re: JeffC]
#357000
06/27/09 09:07 PM
06/27/09 09:07 PM
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Joined: Jan 2003
Posts: 5,270 Missouri
MY340
master
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master
Joined: Jan 2003
Posts: 5,270
Missouri
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I found out first hand how erratic the tranny shifts will be with out the proper setup. Before I put my custom turnbuckle equipped rod on my Duster it would either shift too early or too late depending on where I had the pivot piece wired back. The car came without a kickdown rod but luckily the fresh tranny wasn't driven much before I got the car.
With the turnbuckle made into the rod I can make fine adjustments very easily and the car shifts great now.
1970 FE5 Duster 360/904/3.91's SOLD
1973 TB3 SpaceDuster 340/4spd/4.10's SOLD
Moparless for now but when the opportunity is right I'll have another one.
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