Will a C6 transmision fit a 70 mav?

Ford had one primary auto tranny carry over from the 1950s. FMX

The C4 was made for lighter duty applications, and the C6 was made for big cars and trucks. The FMX hung around too, for medium duty apps.

The bottom line is: Why put what is essentially a truck transmission into such a small car? The C6 eats horsepower in more ways than one, and it is huge. Just build a stout C4.

 

I agree build a C4... can be built fairly reasonably priced and will last a long time.

I do agree C6's are strong and will last a long time, but a properly built C4 will last just as long or longer.

It also is made for the car... direct bolt in and no need to beat up or cut a firewall and trans tunnel.

 

The C4 was used in cars with 4 cylinders to eight, 60HP to over 300Hp in stock form.
I have seen many C4s with close to 100000 miles that have NEVER been serviced and still work when pulled. The C4 that came out of my 73 Maverick had over 100000 miles on it and was running when I pulled it out and put in a "Paul's street and Strip" C4. The transmission had never had the pan off! It was suffering from "Morning Sickness" for two years before I removed it. The C4 I built for it ("Paul's Street and Strip" is me) will be in there for the life of the car. (no matter what I do with the engine) I replaced the transmission in my wife's 73 Maverick with a "street only" C4 that I expect will live very well for the next 40 years in her car. I don't feel this is a big feat because the stock C4 lasted 35 years in stock form.
No automatic survives a shelf life very well because the seals in the clutches go flat where they rest in the drum. Friction materials can dry out over time and then glaze when run if they are not well lubed before power is applied to them. The C6 and C4 yse the same power flow (the C6 is just bigger and uses a low clutch instead of a band) through the shafts and planetaries. They ae big and little brothers of the same design. The low/ reverse clutch causes more drag than the low / reverse band so the C6 uses more power in second and third gears than the C4. The c4 is being used currently behind 429 and 460 engines with no reliability issues. I have personally built C4s for engines running 1000+ HP and they are hard to beat with any transmission. I used to see a lot of C6 cases twisted by similar engines due (in my opinion) to the large open area of the pan. We came up with a work-around for the C6 by adding a steel girdle around the pan rail and adding a deep sump pick-up. The steel box kept the case from twisting but added a lot of weight. That's when we started adapting the C4s to the big engines. I have never looked back. The C4 can be built to do anything that the C6 can and with a lot less weight and less power consumed in the process.
The C6 definitely has its place. If you are towing a fifth wheel trailer then the C6 can handle the extreme loads for a longer period of time but if you are running down the drag strip then the C4 will last just as long as the C6. (both being properly built)

 

Thanks for the GREAT info

 

There was a test done about the c-4 and c-6, which was quicker in a drag race and this is what they did: They used two 68' or 69' ford torino's, both had a 351w and the same rear gear, same in every way except the transmission. The one with the c-4 beat the one with the c-6 over and over again. Reason, it takes about 50hp for the c-6 to operate, while the c-4 winds up much quicker, which turns much faster. c-6 is a good transmission but for racing, i will going with a built c-4. leave the c-6 in your f-250. but for really big time drag racing, I hate to say it but, a powergilde.

 

I have a SBF C6 that was behind a 300 I6 in a '78 Econoline. It had like 370,000 miles on it without ever being apart, and still worked, but slipped bad and needs to be totally gone through. Anyone wants it, they can come get it, because I'll sure as heck never run that heavy ass thing in my car. I can pick a C4 up and carry it around about anywhere. I tired to carry that C6 once, I made it about 10 feet before it kicked my ass. I should have got rid of it while scrap prices were high.

 

If you were closer, I would have take that c6 in a heartbeat, just for a spare.

The gear ratios in C4 and C6's are the same also for you guys wondering

 

Ditto, I'd take it too.

 

Did any Mavs come with C6's (I'm guessing not based on this thread).

My Mav has a C6 and I am wondering why the guy who restored it would have bothered if they are simply a horsepower killer.

 

You may need to look again. A C-6 is a tough fit in a Maverick. The one Maverick I saw with a C-6 in it had holes drilled in the floor just to reach the tranny to engine bolts. It also hung way down below the car at an awkward angle. My conclusion.......a C-6 won't fit a Maverick.

 

I'll definitely take a look when I am back home again. I'm going by what I was told before purchasing the vehicle (didn't really give it a second thought until I started reading these threads). I'm in Texas this week and my Mav is back home in Wisconsin getting painted. Perhaps they were BS'ing me. Here is exactly what I was told:

"tranny is a C6 and it has a 3:08 9 inch posi rear end"

At the time, the only thing I took away from that statement is that the vehicle had positraction. (I've been wrenching on my motorcycles most of my life, but I have never been a big car mechanics guy...obviously didn't know anything about Ford tranny naming convention and history and don't really have any idea what the rear end gear ratio means real world to me)

 

Let us know what you find out.

 

Thanks You PaulS

On 19 Jan 2009 you wrote about the differences between C4 (not the explosive) and the C6. I am at the same fork in the road and found great comfort in what you said. I have rebuilt some trannys in my day and have always liked the C4. But you have helped me to make up my mind because I am ready to put a more horse pwer engine in my Mav. Again Thanks.

 

"Morning sickness" in a C4 is a condition that causes the forward clutch to not engage when first started until it warms up or sometimes only a few seconds to a minute. The temptation is to "rev" the engine to get it to engage faster - that burns the clutches up fast.
The only cure is a rebuild - the apply piston seals in the clutch packs are usually hard as a rock and cracked. Replacement is the only cure.