Ford C4 Transmission Overhaul - Teardown and Assess 

Some people enjoy jigsaws, some prefer a more practical, mechanical, puzzle. Nice job Peter.

Two other traps are.....there should be a small filter/strainer located in the Governor support which is often lost or discarded. I always remove them, clean them and refit. If missing i source a new one. Also there is a spring loaded check ball in the stator support half of the front pump assembly. This must be pressure tested to ensure it is working properly as it will not allow fluid to flow to the cooler if it is non functional (common when a transmission has sat around out of the car) It also pays to put a kit of either springs and rollers or at the very least a set of wafer springs in the one way clutch unit. The springs are directional in that they fit better one way than the other.

C10 is a nickname bestowed on the C4 by the Automatic Transmission Rebuilding industry (which i was involved in for many years) We did this for identification purposes. We also used the C4, C8, C9 and C9 Six Cylinder as well as C10 monikers as a means of identification when ordering parts from our suppliers.

Awesome video Peter - very informational, I was going to rebuild the C4 for the hotrod but with 400+ horsepower windsor I decided to get a new already beefed up one, but I might rebuild the old one at some stage to recoupe some costs

Pete, C4's were also found in all 351 2V Aussie Cleveland powered passenger cars (XY to XB and the first three months of ZH Fairlane's - April to June 1976 as these were running XB mechanicals). Only the 4V 351 - XW to XE, used the FMX. To further expand on the C4/C10, the C = the 1960's and 4 = = 1964. Same for C6 = 1966 year of release. The usage of C10 although incorrect did actually assist in way of differentiating the changes in the C4 transmission of the years. The C4 prefix always remained, it was only the suffix that changed

In my opinion mate,you should replace all frictions and grab some steel plates as well so you can replace the worst ones. Might also be a problem in the pump (scratches,etc etc ) causing a reduction in line pressure which could be the culprit for the burnt steel and friction plates...cheers

Hi Pete,you will find that Scotch Brite is your best friend on those drums.We used to pop them on the lathe and scour them clean but anything that won't clean up,use some wet and dry and then scotchbrite.. cheers,Rach

Always a pleasent suprise when your expecting the insides to be stuffed, but when the covers come off its clean as

Geez mate, turning up to work on your day off! The C4 family basically. C9 and 10 are all similar apart from dipstick positions and input shaft(?) You'd probably know better anyhow as you worked at Ford! Great story from when I had C4 in my Ute, it wasn't reaching 3rd gear. Took it back to guys who rebuilt and installed it, and they assumed it was a governor valve problem. They drove the car up to 60kmh, and he says "brace yourself" and threw it into reverse, then drive to wake the valve up. Problem fixed. He said and I quote, this is NOT in the manual, so don't try this at home...i can tell you, that was scary to hear and feel at the time. Never knew that could be done. No wonder i have a 5 speed in it now lol

Good stuff Peter

It pays to take up clutch pack clearance using selective (thicker) steel plates when doing the final assembly. Along the same lines it also pays to take up any excess gesr train end float via the use of shims or selective washers on the back of the pump.

Great video, Peter. I enjoyed the teardown.. Wish it had come a month earlier. Lol. Having a friend's C4 rebuilt at this time..I would certainly have tried to rebuild it myself, with your help of course. Lol Be well Peter and please check for my name on your Patreons supporters... Peace and love from Parma, Mi.. Take care my friend!!

Peter, this is Andy in Canada and for some reason my ID is different now. I think I created a new ID at some point. FYI, the crank seal fix for the Suzuki worked and I have been bombing around on it ever since. The gears are working great.

Hey Pete, I saw you over the Easter holiday on my home at BP Geelong bypass. I didn’t get the chance to say g’day.. any enjoy your content cheers👍

Hi Peter. Great to see you again and thank you for the video. Hopefully get to learn how to do a C4 for when I am ready to do one. The C4 which came out of my XD 351 was a built transmission at the time before I took it out and disassembled the whole car back in 1992. It had a stage 2 shift kit, which I know nothing about except for it having really strong, tight shifts. It was magnificent. It would spin the wheels in second gear and go sideways (LSD) too. When I pulled it, It was sealed up and wrapped in a blanket and dry stored since 1992. Question. Do you think it will need an overhaul or you think it will be ok to just put it back in and do a fluid flush etc ?? Is it possible the guts could go bad from no usage ? I doubt it could go dry. What would you think ? I never drained it either and the torque converter remained attached, so it should still have most if not all of it's fluid. I don't want to strip it if I don't have to. Others feel free to chime in too if you have experience with these C4s. I also have a C6 which came with a couple of spare Clevelands. Both out of an F100. I'll probably sell the C6 if it's not useful on the 351. Would the C6 be a better option to the FMX ?

Very interesting Peter, seeing the C4 being pulled apart. Great knowledge you have. 👍. What is the best way to reach you “offline”?

Good video pete

Peter. Thanks for the video. Now I get to feel bad that I plan to do a motor swap and not even touch my C4 transmission in my Fairlane. Maybe you can plan another trip to Canada to help rebuild my C4 when I grenade it.

this was really helpful thank you

Definitely did come behind 351's Many Falcon's and Fairlanes were C4 not all were FMX ;) Don't believe those stupid H.P figures from a silly magazine are years ago Modulator adjustment does not lengthen pin, It adjusts preload on the internal spring.

Make sure you do the governor modification

Hi Peter, i was wondering where youre going to source your transmission parts from, i have a Jag 420g with a borg warner model 8 or 12 gearbox that i read that the fmx was based on. Mine lost all the gears last year

Interesting, I have never seen the internals of an automatic transmission before.

i subbed

Nice mate should come up a treat 👍 We have a turbo 350 to pull a part when your ready haha

Drive it to 40khms an put it in park obviously it wont go into park because of the 2 hardened surfaces that'll unjam the governor valve providing you haven't got a lot of metal in em i always modify the governor on c4s

Hey Pete, I’ve got a case filled C4 that was rebuilt about 7 years ago and has done less than 1000km since. When I select reverse or 2nd I get this buzzing noise that comes and goes. In drive I have no noise and shifts perfectly. Any ideas what it could be?

Look how uncomplicated that is compared to a modern transmission.

Now we all know you will disassemble and clean the sprag….every time you say you won’t bother with something you always do anyway 😅

May i ask are you teaching kids to work with wood Pencil box style Pete ?

I’m still surprised that anyone knows how an automatic transmission works. To me it’s not human technology. I’m sure that it’s alien technology that was found in a ship that is in Area 51. The fact that someone can pull one apart and put it back together again is unbelievable to me. I’ve watched a few videos on automatic transmissions and still have no idea how it works. 😂

Zf 351 AND C10 ALL std