Do I really need to hook up the passing gear on a C-4 and C-

junkyardjeff · December 21, 2010, 05:04:21 PM

I put a C-4 in my 55 sunliner and there has been a minor issue with it since the installation,I have ran C-4s without the passing gear hooked up before with no issues but I want to get by with the C-4 for another year or so since it will be replaced with a Y block and FMX and dont want to waste money rebuilding the C-4. I also have a C-6 in my 66 F250 that I need to hook up the pasing gear too.

WZ JUNK · December 21, 2010, 05:37:14 PM

Quote from: "junkyardjeff"I put a C-4 in my 55 sunliner and there has been a minor issue with it since the installation,I have ran C-4s without the passing gear hooked up before with no issues but I want to get by with the C-4 for another year or so since it will be replaced with a Y block and FMX and dont want to waste money rebuilding the C-4. I also have a C-6 in my 66 F250 that I need to hook up the pasing gear too.

I do not know the answer but I need to know as the Ford that I am currently wiring does not have the kick down connected. I was told, by my transmission guy, that a GM 350 turbo ( and possibly other GM trans) must be used and set up correctly. Something about that it also controls pump pressure in the transmission.

John

junkyardjeff · December 21, 2010, 05:50:49 PM

My trans has always had a wimpy shift into third at light throttle and was discussing it with a local trans shop on a possible rebuild,its been so long since he rebuilt one he could not remember if the modulator valve or kick down controlled pressure. I asked about the governor and he said its made for the application and the trans I have came out of a early 70s 3/4 ton van that probably had 4.10 gears and I put it in a car with 2.79s so if thats true if I replace the trans I will look for one out of a car. I cant put a factory kick down rod on both vehicles due to non factory carbs and not being in the original applications so I will use a aftermarket cable type kick down if I do hook them up.

WZ JUNK · December 21, 2010, 06:33:32 PM

All that is there on the car that I am wiring is the arm on the transmission. A GM is just a simple cable that hooks to the trans and then to the carburetor. I do not know what this Ford will require. I have not looked at the catalogs yet to see what is available.

John

junkyardjeff · December 21, 2010, 06:41:56 PM

Lokar sells kick down cables but they are about 100 dollars at Jegs and Simmit but I have found a small rod shop that has them cheaper,I am going to hook one up on the C-4 and see if it helps but will wait on the C-6 since the truck is not ready for the road at the moment

phat46 · December 21, 2010, 07:09:53 PM

Quote from: "WZ JUNK"
Quote from: "junkyardjeff"I put a C-4 in my 55 sunliner and there has been a minor issue with it since the installation,I have ran C-4s without the passing gear hooked up before with no issues but I want to get by with the C-4 for another year or so since it will be replaced with a Y block and FMX and dont want to waste money rebuilding the C-4. I also have a C-6 in my 66 F250 that I need to hook up the pasing gear too.

I do not know the answer but I need to know as the Ford that I am currently wiring does not have the kick down connected. I was told, by my transmission guy, that a GM 350 turbo ( and possibly other GM trans) must be used and set up correctly. Something about that it also controls pump pressure in the transmission.

John

I don't think the Turbo 350 needs the kickdown hooked up. I have been running without one on a $50 "mockup" trans since 1993. I put a shift kit in the trans and abuse it every chance I get, it is just a $50 trans after all...

jaybee · December 21, 2010, 09:23:17 PM

Not certain about the C4 or C6 but I had an FMX I ran with the kickdown disconnected for a while due to a carb swap. The position of the lever had a very pronounced effect on shift firmness.

wayne petty · December 21, 2010, 11:07:28 PM

C4 , C5 and C6 transmissions

not sure about C3 transmissions...

nor is the Kick down needed on TH350s...

the kick down commands the passing gear.. the under load 3-2 or 3-2-1 shift if you put in all the check balls...

i did that in a C4 in a friends 74E300 ford van.... talk about wild... tromp on it.. kicks all the way back to first gear... talk about overrevving...

glad i had ported those heads... he was out with that one ton van blowing off 5.0 mustangs..

one thing....

since you have a C4 already... and C4s are really straight forward to rebuild... mostly...

you might want to double check me... but i seem to recall that the 5 bolt pattern used on 260 fords and 5 bolt early 289s is the same bolt pattern as the ford Y block... i could be and usually am wrong on things like this.. and 5 bolt C4 bellhousings are worth gold ...

junkyardjeff · December 21, 2010, 11:33:08 PM

I am going to install a kick down and see if it improves,the trans shop wants about 500 to go through it if I pull it so I dont want to waste money on a trans thats not going to be in there too long. It might be time to take a class on automatic trans so I can rebuild the C-4 and FMX myself so they could be rebuilt cheaper and learn to do it myself.

chimp koose · December 22, 2010, 11:06:42 PM

Ford went from 5 to 6 bolt bellhousings part way through'65. If you have a rebuildable 5 bolt BLOCK you have struck gold.Mustang restorers get giddy over a find like that.

wayne petty · December 23, 2010, 12:14:49 AM

chimp...that was not what i intended...

i have memories... that the 5 bolt bell housing pattern for the 260/289s are also the same for the Y blocks...

and that if he had a 5 bolt C4 bellhousing kicking around.. he might be able to just switch bellhousings to mount the C4 to the Y block...

chimp koose · December 23, 2010, 07:51:58 PM

Wayne you are most likely right. I was just trying to make a point that the 5 bolt windsor block is worth a small fortune.

Crosley.In.AZ · December 23, 2010, 08:58:47 PM

the hook up to the carb works with the vacuum modulator to control shift points up and down.

The modulator determines internal pressure increase as the engine load goes up, vacuum goes down ... trans main line pressure goes up. this will also delay upshifts some too.

You can also slightly adjust pressure in the trans via the pin in the vacuum modulator.. this pin is between the modulator and the inner valve that acts against the oil pressure.

Shorter pin = earlier shifts , softer shifts.

Longer pin increases pressure and later shifts.

Do not change pin length by more than 1/16 of an inch at one time. It usually is best to make a new pin from steel welding rod and keep the OE pin set aside