What's the relationship between shift point and kickdown adj

MilesnMiles · Post by **MilesnMiles** » Sat Sep 28, 13 7:06 pm

I need some schooling on this.
My old 360/727 with tf2 shift kit would change from 1-2 at about 5,500rpm at WOT.
Today I did some road testing in my RR with 340/727 and the same shift kit.
If I floor it it changes very quickly to second gear and is 'off' the cam so the engine loses speed until the revs pick up. Once it does it start to pull hard until it shifts at around 4,500 @70 mph or so.

My question is this. What is the exact relationship between the kickdown lever position and the trans shifting thru the gears?
I need a longer first gear before it shifts.
I know there is a relationship because some years back I wrongly adjusted the kickdown and couldn't get third gear until 50mph or so!

Having fitted a new carb I have reset the kickdown and it may be incorrect even though it functions fine when used.

Dave-R · Post by **Dave-R** » Sat Sep 28, 13 7:14 pm

The further back the lever pushes the kickdown on the trans (longer rod), the longer the trans will hold in gear (higher rpm between shifts).

MilesnMiles · Post by **MilesnMiles** » Sat Sep 28, 13 9:18 pm

Dave, do you mean when using the kickdown function?
Or, do you mean with the kickdown rod so positioned as you say the trans will stay in gear longer under WOT without using kickdown?
I can then check it tomorrow morning.

Cannonball · Post by **Cannonball** » Sat Sep 28, 13 10:08 pm

MilesnMiles wrote:Dave, do you mean when using the kickdown function?
Or, do you mean with the kickdown rod so positioned as you say the trans will stay in gear longer under WOT without using kickdown?
I can then check it tomorrow morning.

right miles the kick down mech needs to be fully pushed rear ward at hard full throttle if your road speed is low enough it will kick down in to the lower gear,it does just that kick the sucker pedal hard to down shift.
i know you already knew this so if it works as it should then your basically correct on the linkage set up now lets say you set of on a medium throttle and it up shifts to quick a little cheating is required you need to start pushing on the rod sooner but not so much as this set up restricts full throttle, in the past i have made some sort of stop so that even with no throttle the kick down rods are held back just a bit so that on a light to medium throttle the shifts are later rather than just flipping straight through making it sluggish or labour,
but your not asking about this i assume you have the kick down working correct as you say it does kick down,
and also i assume you are setting of from rest full throttle hard on the floor boards and even though the linkage is set ok it up shifts to 2nd then to 3rd to soon ????
if that is whats happening you need different govorner weights in the govorner you must have sort of light duty passenger car or truck weights you need some from a performance era trans you can buy the weights aftermarket or i may have what you need its a prop/mount/ extension housing job to get to them,,

MilesnMiles · Post by **MilesnMiles** » Sat Sep 28, 13 10:23 pm

Hi Dunc, thanks for such a detailed response

Yes, the kickdown is working fine.
My concern is when flooring it from idle. It shifts very early into 2nd gear. It stays a long time and pulls hard thru second as I would expect, no problem.
I just need it to pull hard right thru that first gear rather than changing up early.
I will re-test tomorrow and post up the rpm shift point/ and see what you suggest.
Thanks,

Mossy68 · Post by **Mossy68** » Sat Sep 28, 13 10:31 pm

MilesnMiles wrote:Hi Dunc, thanks for such a detailed response
Yes, the kickdown is working fine.
My concern is when flooring it from idle. It shifts very early into 2nd gear. It stays a long time and pulls hard thru second as I would expect, no problem.
I just need it to pull hard right thru that first gear rather than changing up early.
I will re-test tomorrow and post up the rpm shift point/ and see what you suggest.
Thanks,

Mine is the same Miles.
I was meant to take it back to GS who rebuilt the box for adjustment but due to little time and Pete ( GS) being on his own due to Paul's death I havnt done so.
Be interesting to see how you get on so I can have a go myself

Cannonball · Post by **Cannonball** » Sat Sep 28, 13 10:45 pm

if either of you can,t get the shifts in the right place to save the work to dig deep, just hold it in gear manually and do your own up shifting,

MilesnMiles · Post by **MilesnMiles** » Sat Sep 28, 13 10:50 pm

Can do Dunc, but never needed to before. I usually manually shft 2-3 only. I'll have some fun road testing tomorrow and feedback with rpm shift numbers.

Mossy68 · Post by **Mossy68** » Sat Sep 28, 13 10:51 pm

Cannonball wrote:if either of you can,t get the shifts in the right place to save the work to dig deep, just hold it in gear manually and do your own up shifting,

Been doing that Dunc. Gets a bit scary without a tacho or limiter though !!!

MilesnMiles · Post by **MilesnMiles** » Tue Oct 15, 13 5:57 pm

Took Dave's advice and lengthened the rod tonight. Immediate change; punched it hard and spun the wheels in second gear with first gear giving the impetus to change up at higher revs. Feels much stronger and better part throttle kick down too

Also read up on Dunc's advice and found this which helped explain how the governors work;

http://www.moparmusclemagazine.com/tech ... ewall.html

Mossy68 · Post by **Mossy68** » Tue Oct 15, 13 6:33 pm

Cheers for posting Miles.
Glad yours is sorted