View Full Version : Down Shift Linkage


Columbus Comet
2007-03-10, 19:14
Can you run C4 without downshift linkage. It's a stock tranny. Replaced carb and intake with eldebrock performer and couldn't figure how to hook it up.

don graham
2007-03-10, 19:21
i don't have any on mine. it's a track only car. but, i would think it's the same principle. if i want to go faster i just give it more gas.:)

ford84stepside
2007-03-10, 19:56
I've ran my 84 pickup without a kickdown linkage for years. Matter of fact, I took it loose because when it downshifted, it would actually slow down instead of going faster! I think it is a C6, but still the same deal as a C4. You can always manually downshift it with the shifter if you needed to.

Mavaholic
2007-03-10, 20:20
Its only used for kicking down a gear for passing. You can do the same thing by pulling the shift lever down. Will work just fine without it.

Craig Selvey
2007-03-10, 20:39
If you have an edlebrock carb....you just need to buy the linkage for the kickdown.

Columbus Comet
2007-03-11, 00:29
Thanks guys

PaulS
2007-03-11, 03:30
Yep, it'll run "fine" without the kick-down linkage but it won't run right.
On the street you can have problems with double shifts going to high and soft down shift from 3 to 2.
Most of the time it all seems fine and unless you had a gauge on it you won't notice the damage being done. Let's face it - if it ran right without the linkage Ford would save the millions of dollars it spends (spent) installing and adjusting them.

Mavaholic
2007-03-11, 05:46
Yep, it'll run "fine" without the kick-down linkage but it won't run right.
On the street you can have problems with double shifts going to high and soft down shift from 3 to 2. Thats BS. It will run fine without it and it will not do any damage.

Blown 5.0
2007-03-11, 08:51
The downshift linkage is actually a line pressure booster, You can run without it BUT with a lot of power or a worn trans you may slip clutches, FORD did put it there for a purpose. I do run the linkage on mine, its only triggered a wide open throttle. Lockar makes the linkage just for a C4.

PaulS
2007-03-25, 18:17
Thanks for the input Blown 5.0.
Its good to see that there are people who understand the inner workings of the tranny.
Manually shifting also increases the line pressure too. So if you always shift manually then you have no need for the kick-down leveror valve.
Paul

Columbus Comet
2007-03-26, 05:54
Thanks for information. Maybe I'll check into the locar cable.

blugene
2007-03-26, 11:40
The downshift linkage is actually a line pressure booster, You can run without it BUT with a lot of power or a worn trans you may slip clutches, FORD did put it there for a purpose. I do run the linkage on mine, its only triggered a wide open throttle. Lockar makes the linkage just for a C4.
I am installing one of these cause I have an automatic and would like to use that function when not in challange mode...LOL!

Phyphor1
2007-04-16, 01:10
Can you run C4 without downshift linkage. It's a stock tranny. Replaced carb and intake with eldebrock performer and couldn't figure how to hook it up.

Yea, you can run w/o the passing gear linkup. But you'll have to drop to 2nd manually if you want to kick it down from high! ;)

PaulS
2007-04-16, 16:44
The problem of running without the "downshift" linkage working is that you never get the increase inpressure until you move the lever manually. Every time you go up a hill the transmision needs a boost in throttle pressure to keep the clutches from slipping a bit. every time you start to press down on the gas pedal at low speeds you are adding torque to the tranny from the engine without adding any pressure to the tranny. The modulator will add some pressure but it is nothing like the Kick-down.
Now if you are running a full manual valve or have boosted the pressure with a super spring in the pressure regulator then you have enough pressure that you don't need the added pressure of the "kick-down" valve. On the other hand, if you are running a pure stock tranny then you are going to hurt the tranny and it will fail. Usually the forward clutches will fail first and they are followed by the direct clutches.
From my point of view you would be better off not running vacuum to the modulator - at least THAT will ADD pressure and not take it away. (don't do it - your tranny will shift very hard under decelleration and it will shift very late in a mushy sort of shift without the Kick-down linkage hooked up. Give your transmission a break and let it work right so it will live a long and satisfying life, bringing pleasure to the driver and reigning discomfort on the passengers.

broncoisl
2007-04-16, 16:53
Should this be a cable or a rod? It's missing from my car.

PaulS
2007-04-16, 17:06
Cable or rod? Ford had rods that connected from the throttle lever to the linkage at the tranny. Lokar makes a cable kit that has the proper bracketry to make it work.

Craig Selvey
2007-04-16, 20:36
Paul:

Is a "spring" required on the kick down lever? I have seen some cars with a helper "spring" and some without.

dkstuck
2007-04-16, 21:46
Agree with PaulS 100% on this! Lokar cable works great

hotrod-daddy
2007-04-16, 23:10
Agree with PaulS 100% on this! Lokar cable works great I too go with LOKAR :thumbsup:

blugene
2007-04-17, 08:18
Cable or rod? Ford had rods that connected from the throttle lever to the linkage at the tranny. Lokar makes a cable kit that has the proper bracketry to make it work.
The "bracketry" is extra...but not too much, I think like $20 or under.
Unless you have a show quality car I wouldn't spend the cash on the polished stuff, it doesn't look much different.

PaulS
2007-04-17, 13:38
Ford puts a small spring to offset the weight of the rod. With the cable I think they use a spring to assist because of the cable drag.

The way to adjust it is with the throttle wide open and the kick-down lever completely depressed there is .060 clearance between the linkage and the adjusting screw. I think as long as you have some clearance and it isn't binding you're OK.

blugene
2007-04-23, 19:30
I have been installing this kick down cable today and it is a pain:whew:... The cable is lined up with my B&M shift cable with every thing mocked up...I guess it's time to hold my toung right and start tweek bending the levers. The indtructions say to cut the braided shield and the cable, I chose not to. Any pointers before I procede? :smash:

ChadS
2007-04-24, 09:13
What about trying to build a bracket that you can set the kickdown rod at a locked position? Like putting a turnbuckle off the kickdown linkage, and test drive for shift feel. I had a AOD one time, in a 88 t-bird, unhooked the cable, and I adjusted the cable, tied it back with a bread sack tie, after a few test drives, I got it to shift 1-2-3-OD like clockwork, and shifted like it had a shift kit in it. Can this be done to the C4? or the same principle work? I have EFI, and its kinda difficult to rig something up, and if it can work like it did on the AOD,, Thats the way I like it! LOL! Theoreticly speaking, can it be done? ChadS

PaulS
2007-04-24, 14:53
The AOD uses a throttle pressure rod, which is similar but different in function. If you "set" the kick-down rod at a certain place it will shift down roghly under light throttle while slowing down and that would be unpleasant at the very least. It must be timed to the throttle. There are kits available to hook it up to EFI, many different carbs and some of the earlier "Hilborn type" mechanical injection systems. You could fabricate a "secondary" linkage from the firewall to the lever on the transmission if you wanted to take the time. The lever at the throttle just have to travel the same distance in a line with the lever from contact with the valve to full throttle. Then you set it with about .060" free play at wide open throttle.
The kits are easy to install and not that expensive.