c-4 rebuild

I've always been scared shetless of doing that. Do you have excellent accounting skills (memory doesn't cut it)? You'll need special tools for certain parts & it's recommended you have an engineer vice, whatever the hell that is. What sort of workspace do you have that can be dedicated? You'll need lots. How badly do you need access to the car if the project doesn't go as planned?

Hey not to discourage you though. If things add up, go for it.

I suppose if you have a digital camera you could always post pics of what you're doing on here. People love to see blood (ATF) & guts.

I've rebuilt several C4 transmissions. First if you are even thinking about it BUY A BOOK! The Haynes Ford transmission Techbook is a good start. There are other better books but this is usually easy to get and fairly cheap. READ IT! If it looks like too much for your ability don't even attempt it. If you think you have the ability try it. You don't really need any "super special" tools. Feeler guages, a dial indicator with a magnetic base, a low range torque wrench and a small press (engineering vise) is nice but unecessary (a couple of C clamps works). A nice large CLEAN place to works is a must. Dirt and junk are big time trouble in any automatic. If you have a local transmission shop that is willing to work with you that is even better. My local shop owner was great. I bought a rebuilt pump from him and told him what I was doing and he said if you have any questions/problems stop around and I'll see what I can do.. Not all places are like that but some are... If you toss some work his way he might be more likely to give you a hand/advice. There are some bushings that might be replaced that he would have the ability to replace easier then you. A great place to get parts is http://www.bulkpart.com Good prices and quality products.

Good Luck!

Tim

I've never built one, I've just taken them apart after breaking them and tinkered with it to see how everything works.

A C-4 isnt a very strong transmission, even rebuilt with extra clutches and a shift kit in the valve body. That's why I've broken a lot of them. If you buy a race-prepped C-4 from somebody like Dynamic Transmissions, who specialize in race automatics, they install much stronger custom parts inside, (such as a solid front drum, and vasco input shaft) as well as machining the bushed areas and upgrade to full roller bearings.

If the trans was stronger, like a C-6, then rebuilding with some mild performance upgrades would be nice, but a C-4 sucks and needs a lot of specialized work to make it live behind a performance motor.

Blue Thunder said:

I've never built one, I've just taken them apart after breaking them and tinkered with it to see how everything works.

A C-4 isnt a very strong transmission, even rebuilt with extra clutches and a shift kit in the valve body. That's why I've broken a lot of them. If you buy a race-prepped C-4 from somebody like Dynamic Transmissions, who specialize in race automatics, they install much stronger custom parts inside, (such as a solid front drum, and vasco input shaft) as well as machining the bushed areas and upgrade to full roller bearings.

If the trans was stronger, like a C-6, then rebuilding with some mild performance upgrades would be nice, but a C-4 sucks and needs a lot of specialized work to make it live behind a performance motor.

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I don't want to start anything here. But I you really need to do some research. The C4 is a plenty strong transmission for a small block without any special parts! They wouldn't have made a bellhousing for behind a 460 or an FE if the C4 were a weak transmission. If you take your time. Buy good parts, have someone who has a clue work on it then the C4 is a kick ass transmission. I just rebuilt the C4 from my buddies 85 Mustang Drag car. 351W powered, runs mid and 11's wasn't touched for 2 years. It finally toasted the clutches. Rebuilt it, stuffed a couple of extra clucthes in it and it's ready to roll. Anything can be broken if used improperly or abused. Sure if you take a factory V6 preped C4 and stuff it behind something with 2-3 times the torque and HP you are going to have issues. There are differences between C4's made for different motors. Just do your homework. It will be worth it in the end.

Tim

I've never built one, I've just taken them apart after breaking them and tinkered with it to see how everything works.

A C-4 isnt a very strong transmission, even rebuilt with extra clutches and a shift kit in the valve body. That's why I've broken a lot of them. If you buy a race-prepped C-4's from somebody like Dynamic Transmissions, who specialize in race automatics, they install much stronger custom parts inside, (such as a solid front drum, and vasco input shaft) as well as machining the bushed areas and upgrade to full roller bearings.

If the trans was stronger, like a C-6, then rebuilding with some mild performance upgrades would be nice, but a C-4 sucks and needs a lot of specialized work to make it live behind a performance motor.

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I ran a C-4 behind a 600 hp plus big block 460 with blue thunder heads, and many other go fast parts.........and it NEVER broke. Maybe you should go to another builder bro. Dynamic (harold miller) is the absolute best there is building C-4 and the only thing I've ever broke in a C-4 was.....NOTHING, I only wiped the clutchs out a couple times. IF you broke something which parts was it? plentary? input shaft? convertor?
Serious dude......if you've broken that many C-4 either you were putting out way to much horsepower for the level of C-4 you had or your building was shafting you!
Ben

jackchan said:

I ran a C-4 behind a 600 hp plus big block 460 with blue thunder heads, and many other go fast parts.........and it NEVER broke. Maybe you should go to another builder bro. Dynamic (harold miller) is the absolute best there is building C-4 and the only thing I've ever broke in a C-4 was.....NOTHING

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I'm seriously happy with my C-4 from Dynamic, and I couldnt believe they waranteed it for a year. I drove right over to their shop in CT, (less than an hour, if I recall) so I saved some truck freight, too.

I know so many guys who have blown up C4s, both screwing around on the street with radials and at the strip with slicks. Other than the 1968 special police C4 I had in my car years ago, none of them lasted me more than two summers. The '68 unit was awesome, it had an adjustable modulator, so I could set the shift points, and it shifted firm enough to bark the tires in both 2nd and 3rd gear. It finally broke the 2nd gear band in half, so I drove the car the rest of that summer shifting from 1st into 3rd. I still have that old trans, stashed away, maybe it'll be worth something.

I would never run a C4 anymore unless Dynamic built it.

P.S. What bell are you using with the 460/C4?

I believe I have heard that some monster trucks were running c-4's.

If it will take abuse from a 10'000 lb truck, I guess it'll work just fine in our II'S.

I've had my 78 coupe for 26 years.

Trans. has been 23 years since rebuild. 80 plus thousand miles and still going.

Well I haven't seen the 460 application either. A 400 yes, several times, which has it's own FE applications well all know and love. Let alone 351C applications. While I'd would agree the C4 needs help to handle 400+ horses flogged frequently on the strip, I've seen last for years with 300+ without issue. Granted C4/C6 agruement aside, the main issues I've seen is poor workmanship from "professionals". I went through 3 C4's, and multiple swaps of each because "they" couldn't do their job properly and cut corners. Ah the horrors.... on 1st, only 2nd, no reverse....Finally reverted to fixing myself what they were paid to do! I won't even mention the hassle with parts/trannies from G.E.R! More like GRRRRRRRRRHHHHHHHH! Iv'e heard good things about Dynamic, but if I had the cash it would be a Copmetition model from PAW. I haven't seen anyone beat their quality/warranty for the price.

74ProII said:

G.E.R!

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Those guys have a worse reputation than the old Excessive Motorsports fiasco. I have RARELY seen anyone happy with their junkyard/spray painted/sell it as new junk.

I used a B&M kit to rebuild my C4. It took no special tools other then basic snap ring pliers and a couple of huge C-clamps. The B&M kit had very good instructions and pictures. The C4 I built blew-up on its second season. Ratteled I had a proffesional rebuild it. He said the blow-up was due to a faulty band. I am glad I rebuilt one, so I have an idea how one works, and I can now identify all the parts. It was a pain in the ass to rebuild and it took 3 days to complete. I had to pillage through a second trans to get some parts that were broken. It took two day just to clean everything! Transmission shops have large automatic parts cleaners, I had 5 big buckets full of parts a tooth brush and some solvent! The stock II C4 has small drums that do not fit many frictions. I would buy some larger drums. My new C4 has no exotic parts and the builder gave it a 2 year warranty up to 500hp, and he was not worried about the 100hp nitrous kit. My transmission is stock, short of some C5 drums to hold more frictions. I would not build another transmission, but I am glad I built one just for the learning expierence. I felt I was in over my head though 80% of the build, and I was amazed that it worked so good when I was finished! I really don't think you would save yourself much money. Transmission shops have plenty of good used hard parts laying around. I would have been screwed had it not been for my parts C4. It literally took two C4's to make one good one. I would build just one, for the sake of learning and bragging rights. I remember the amazed looks on other car guys faces when I said I built the transmission, like I had performed a tripple by-pass or something!

Dynamic actually found me a II bellhousing, since I didnt bring them a core to rebuild, I bought the trans outright. And they didnt want me bolting the housing on myself, they wanted to do it, so they included the II bell free of charge.

Those of you who've rebuilt a C-4 or done some work on them -- how big of a deal is it to replace the rear servo cover and seal, with the tranny still in the car? I finally identified my leak(s) and fixed one of them -- the O-ring at the speedo cable, easy fix -- this is the other one.

joeythesaint said:

Those of you who've rebuilt a C-4 or done some work on them -- how big of a deal is it to replace the rear servo cover and seal, with the tranny still in the car? I finally identified my leak(s) and fixed one of them -- the O-ring at the speedo cable, easy fix -- this is the other one.

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Not too bad but you are going to have to drop the pan and valve body to be on the safe side. The band strut will probably fall loose once you start pulling the cover off. Remember to get a new bad adjustment nut as well. And to adjust the band accordingly when you get it back together. It's not all that hard just a pain in the butt.

Tim