1972 Ford F100 Test Drive, C4 Transmission Problems

[MrTpengineer]

My tranny is messed up, the column shifter is always off and it won't go into 2nd if I really push it to 4,000rpm it will go into 3rd. Mines a c6.

[Lukinsfamily]

Your kick out is disconnected

[tom58c]

@Lukinsfamily still is, trans works awesome. On the c4 the kick down rod doesn't effect performance. You just have to manually shift down.

[929rrdan]

U should have put flowmasters on it

[929rrdan]

Low fluid

[dal007ALT]

it is actually slipping,add some oil then make sure every little thing is hooked up right

[thycke1]

im havin the same problem with my 74 gran torino i drove it earlier tody stop stalled it up 3 grand and stomped it and it acted like it jumped outta gear everything is new in the tranny idk why it did this any answers????

[MySlick75GMC]

sounds like your vacuum lines arent hooked up right. there's a modulator with a hose that goes a hardline then goes to carb. try f**king with that and see if that dont fix it. my friend has a 73 f100 390 and he was having the EXACT problem yours is having.

[tom58c]

@MySlick75GMC The line was not the issue. I rebuilt the trans agian with new valve body and pump. Its been working fine for a long time now.

[tom58c]

@pinkpanthercow even 400hp is pushing a c4 past its limits unless it is very well built up. Stronger output and input shafts, stronger planetary gear sets, mechined drums for more plates, aftermarket valvebody, and great converter.

For that power though, I would look into a built up c6 for a small block. The c6 starts with a much stronger platform to build off of.

[PX213]

Got my C4 sorted out today. The steel piston that the modulator valve drives using the pin was installed backwards........

Hope you get yours sorted out as well.

That 5 minute fix cured all the shifting problems after tearing apart the governor, valve body, air checks, etc, etc.....

[tom58c]

@PX213 Mine has been sorted for months. I had to rebuild it completely. Got a new pump from summit, whole new valve body from TCI. The works. Works very well and shifts incredibly fast and firm. Has a good sporty feel to it now.

[PX213]

Any news on the prognosis? I just rebuilt a C4 and it has all the same symptoms, but I can't get 3rd gear at all. If I shift from 2 to D, it just revs free.

I am getting ready to pull the governor out since that can be done with it still in the car.......

[HO123virus]

I'm kinda new at this rebuilding. I have a friends truck that I'm working on. It's a 1972 F100, and I'm wondering, is the c4 the only automatic tranny for this year of truck?

[tom58c]

@HO123virus in the trucks as far as 3 speeds go, the small block engines used the c4, the big blocks used the c6. In the vans the small blocks had a smaller bell housing c6 behined them.

[fatmandew7110]

what motor c4 is ment for like a 302 or 351 or 352 I had a c4 on my 67 with a 390 it was doing that same thing thin it went out best trans ever is a c6 I have them in my 67 f100 and 71 f100 I hope you get it fixed

[evilperson86u]

Get an AOD Transmission.... Look at my video to get it setup up in the truck.. Those c4 take too much horsepower anyway...

[gunforme]

@evilperson86u how does a C4 eat up any more HP than a AOD??

[evilperson86u]

@gunforme Thats a good question... I know somebody who messes with mustangs for years and he told me that. By the way, wouldn't you like to have a 4th gear :)....?

[gunforme]

@evilperson86u From my understanding the C4 is not only easier to work on, but eats up less HP than the AOD due to not having the last gear. I currently have a T5 in my 91 GT but am considering the swap to a C4 for more consistent times. I do most of the driving in town and rarely see the highway so I hardly ever use the overdrive anyhow.

[evilperson86u]

@gunforme I wish I could help, but you have c4. I only messed with AOD Transmissions.

[Easye281982]

first take off modulator n make sure it has pin it in on trans most rebuild they are lost if has it try adjusting screw in back of modulator when u pull hose off. If not that then might be crack torque convertor

[demon6696]

any thing yet bud??? mine after rebuild its still the same!!

[tom58c]

@demon6696 you rebuilt it completely and it still does it? im still waiting on parts. Im getting a whole new valve body, pump, rebuild kit, thrust washers and bushings.

[demon6696]

@tom58c yes in my case it still did it.. but i didnt change pump.. only internals... btw we suspect it could be the converter.. im gonna borrow another one and chek it..

[demon6696]

@tom58c letme know what u got.. im gonna take it down next week or so.. i dunno what it could be... we suspect maybe converter ...

[jackrabbit1971]

i have some friends i will check with them maybe they can figure somthing out

[jackrabbit1971]

did you take valve body off ..check the holes where the little bb,s are maybe you got one in wrong or it is sticking i had that happen on my first rebuild

[tom58c]

@jackrabbit1971 I replaced valve bodies and did many other things. Transmission is taken out and already apart.

[ike2729]

check your trans. linkage, try different adjustments moveing them just a little at a time. i hope this helps you

[tom58c]

@ike2729 transmission is out and taken apart.

[OnusofStrife]

Clutch bands?

[tom58c]

@OnusofStrife clutch and bands.... I dont know what your getting at.

[OnusofStrife]

@tom58c I really don't know what i'm trying to get at. I was thinking some of the clutches fuzed together so maybe it can't slip into gear. I don't know much if you didn't notice.

[84Mustang347]

Very nice motor man! That looks awesome! Did you ever get that tranny fixed? This is my 2 cents. On a C6 when you remove the tailhousing there is a centrifugal shift valve bolted to the output shaft. Remove it and take it apart as the piston is probably stuck in the slung out position or spring could be broken. I have only worked on race C4's so don't have any experience with a stock one

[tom58c]

@84Mustang347 Look throught the comments man. Im taking the trans out tomorrow. Thanks though, the motor is runs perfict. Just need to get it to see road time.

[84Mustang347]

Very nice motor man! That looks awesome! Did you ever get that tranny fixed?

[demon6696]

dammit meng..

dropped pan and its clean

adjusted bands

cleaned valve body

and its still doing the same crap! crabs 3rd at 4000 rpms

btw what converter do you have?

[tom58c]

@demon6696 Like ive said to other people, I have done everything I possibly can other then just taking it all the way apart agian. Sounds like you have the same luck im having. I use just a stock converter. I dont know what the stall speed is.

[demon6696]

@tom58c but mine is not recently rebuild..

i suspect a stuck valvebody but i swapped it and had the samee luck..

i really dont know what else.. fark!!

[tom58c]

@demon6696 Cant be a stuck valve, everything is working. Just not how it should. And I changed valvebodies also. No change.

[demon6696]

WTF dude!!! mine is doing the sameeeee frkn thing!! SAMEEE exact thing!!

pls tellme what you found out!! exept i have to take mine to 4000 rpm to shift to 3rd

[tom58c]

@demon6696 Wish i could tell you bud. I gave up the fight with this a long time ago. Im in the prosess of taking the transmission out now. And mabey in a month or so im going to take it all apart and start over.

[demon6696]

@tom58c well im gonna work on it this weekend if i find something i will tell you.

we are gonna start by dropping the valve body and inspect for stuck pistons etc etc..

chek my truck out somethime

[tom58c]

@demon6696 ive changed the valve body out completely. ive changed the vacuum hose, the modulator, ive even taken out the govenor out. I looked at it, nothing was stuck, put it back in, now i have no 3rd gear at all. And I just rebuilt it to. Its just as new as the engine.

[demon6696]

@tom58c i found the governer in my trans was really stuck so i cleaned it today and gonna test it as soon as i fix the servo on the side

[tom58c]

@demon6696 Let me know how it turns out :)

[demon6696]

WTF dude!!! mine is doing the sameeeee frkn thing!! SAMEEE exact thing!!

pls tellme what you found out!!

[79fordblake]

Any progress on this truck?

[tom58c]

@79fordblake No im pulling the trans out when I can. Already have started on it.

[ushouldntjudgeme]

Son, you got permission to date my daughter.....anybody that has the balls to paint and engine like that has got to be grounded well.

[tom58c]

@ushouldntjudgeme seeing what other people have said on your channel makes me not have to say much lol.

[ushouldntjudgeme]

@tom58c people? what people? I cleaned up the comments, didn't know Obama's brown shirts had been posting comments on my channel, Thanks for the heads up. Sorry that you took offense to my post.

btw, since your transmission is a c-4, you might try to ask some classic mustang guys, alot of c-4's in those old cars, a wealth of knowledge with that clan. My Mustang is stil in pieces, but has a c-4 and a 302.

[tom58c]

@ushouldntjudgeme ive asked and been everywhere about it. No one cant tell me whats going on. But this trucks has been parked for a few months and is almost ready to have the trans taken back out. Then winter hit... And I wasnt sure what to think of your last comment. Im not a Obama supporter eather btw.

[TheTim123456789]

i test i would do is the test the 1,2,3 shift at the transmission . To me it seems that the adjustment for 2nd and 3rd is to close together . IE not an internal problem but a linkage adjustment problem .

[TheTim123456789]

Where are you picking up vacuum ? it has to be constent , off the intake cacuum "tree" or plumed from the manifold , not the base of the carb . You have a 2nd ,3rd shift problem , over tighten bands , vacuum leak , modulator problems . sorry can`t just tell ya what it is ... but that all that it can be . In drive or 3rd gear does passing gear ( down shift ) work about 45 mph ?

could be a simple adjustment required .

[darush012]

ill say c4 is a really shitty trans tht what I have in my 88 ranger and it the 4th one we have had in the truck

[darush012]

Id say modulator but if you swapped it and its getting vacuum so idk Id just go with the c6

[79fordblake]

The engine in that truck sounds great. I would have to get use to the paint on the engine, its cool though and you did a good job with it. You have every right to paint your engine the color you want, kinda neat to see one that aint blue, b/c I paint all mine blue, sometimes a black block. What did you do to the engine?

[tom58c]

@79fordblake Im not sure what to do with the trans, Im going to take it out and do something i guess lol. Putting a C6 from a van to fit the small block. and I know that trans works. Thanks though, im going to make my stuff different, always will. The engine is fully rebuilt by me. Still to this day it doesnt have 200 miles on it. it is blue printed and balanced, 302 bored 40 over, edelbrock performer heads and full roller valve assembly.

[79fordblake]

@tom58c, sounds like a very nice 302. I have a 73 swb F100, 74 lwb F100, and a 79 F150 lwb. All with a 302. I love 302's. My 79 Brocno has a 400.

[79fordblake]

Mine does kinda the samething but reveresed. Mine shifts way to fast. In third by 10mph. I replaced the modulator valve and vac line. Hoping maybe there is just junk caught in the governor. Slips going to 3rd, hoping that is just caused by low pressure from malfunctioning governor. I had pan off, no abnormal clutch material.

[72F100SC]

I"m gonna gues and say the motor is a 302? I'm not a fan of all those colors on it, but nice running motor! Good job! As far as the trans, well, that I can't help with. I'm just now starting on ym own trans issues.

[tom58c]

@72F100SC yes its a 302 bored 40 over. im taking out the trans and getting rid of it for a c6 small block trans that I know works.

[daltonjames22]

vaccumm line is cracked and leaking. hope you get it fixed.

[tom58c]

@daltonjames22 I already said the vacuum is fine. already had it tested by a local shop as well, new valve body, govenor works fine, still no difference. now after checking the govenor it wont use 3rd at all now.

[daltonjames22]

@tom58c you may try a different shop. they could have missed something. they are only human... everyone makes mistakes

[tom58c]

@daltonjames22 the whole vacuum line is new! Its vacuums your thumb off. Its not a vacuum problem.

[rockershocker23]

The truck is rebeling due to the nasty green engine. Purple Valve covers.. WTF?

[tom58c]

@rockershocker23 It can be painted how ever the fuck I want!!! Im tired of fucking ford blue!!

[88ford4life]

Sleeper!!



[1972FordF100]

To me before you try a rebuild or anything try putting a vacuum modulator on it. with the modulator just being a rubber diaphram they do rupture over time with tranny fluid. Try that first and hopefully fixes your problem and if that vac tube isn't connected directly to the intake it will have a hell of a time picking up enough vacuum to shift properly.

[tom58c]

@1972FordF100 The modulator has been changed, twice now sence I put a new one on to begin with sence this trans is just as new as the engine. Only has mabey 60 miles on it. The vacuum hose is right on the intake and has lots of vacuum down there. But still no difference. thanks

[LIFT4POWER]

I believe thats a problem with your muffler bearing. It my need a new glass bearing.

[bobsfords]

mine would do the same thing i have the same truck with the same tranny, i got looking around and one of the vaccum lines was broken. mine also will start off in 2nd like that. good luck with everything!

[tom58c]

Im going to try and replace the whole vacuum line here soon.

[huntwds]

I'm not up on this trans model but in others I worked on, this would be a symptom of low fluid pressure behind the clutch pack piston. On some trans they bias the pressure by dumping the flow into a reservoir such as a band piston cavity, sometimes the spring rates are mismatched and all or most the flow goes to the reservoir giving a slow shift at the clutch pack piston, shifting in manually would shift flow only to the clutch pack piston and speed up the shift. Good luck.

[MrFuckoffdumbass]

what the hell are you trying to do? the green goblin engine? thats terrible

[FordNissanChevy]

my ranger 302 rev'd up really high before shifting, i didn't have a tach tho so im not sure what rpm i was at, but it must have gotten into 5 grand

[jonmanch3st3r]

30k is plenty of miles man rev that thing up!!!!

[tom58c]

Only 30 miles... not 30k. This motor is very very new.

[jonmanch3st3r]

ooooo holy shit man thats crazy....i feel ya then on the reving...but when that bad boi hits 500 thats a diff story : )

[tom58c]

Its all good :) It will be a while for 500 with this transmission. I dont drive this truck much at all with what its doing.

[BlackHondaCivicHatch]

Woah!

Your motor is F*ckin Pretty!!

[tom58c]

I try :) Has to look good or its not worth doing.

I was wondering where ya been.

[edzgarage]

Starts and runs great!

[GarrettJDB]

wow that thing sounds amazing!

[tom58c]

Its cool what those edelbrock heads do for sound.