Technical Why not the C4? TH350 vs C4

I like when Chevy folks don’t speak Ford.
I spent my youth messing with Fords.
Built my first personal SBC about 7 years ago.
One piece or 2 piece rear main seal for flywheels. Watch out for 400 flywheels and dampeners. A couple different tooth counts.
Starter mounting. Big bell, small bell, large or small hub trans. tri 5 oil pan and pump Chevy 11 oil pumps, pans and bells. Dip stick side. Needed a early sbc dizzy to clear a tri-power intake. Early small port heads. Early no side mount hole blocks …..
short WP, long WP.
Long shart/short shaft trans. BOP trans
But chevy did do good their trans bolt patterns.

 

Ok, so thanks for not acknowledging any of the other valid points I made, and only further proving my point.

If you aren't a ford guy, it's Greek.

Also, most of those things you mentioned about Chevy motors either have no bearing on the motor/trans matchup point I was making, or are so niche of a 'problem' that you'd have a hard time finding the motor WITH those parts.

I'll be the first to admit I'm not a ford guy, but I have multiple friends that are, and out of that (relatively small) group there are multiple instances of getting screwed over by having the wrong flywheel/ pressure plate/ clutch/ starter/ ect for a ford motor.

Noting that you like to troll, I almost didn't answer you back, but it's funny to me when ford guys don't speak logic.

 

My take on this thread is that the C4 has a removable bell housing, which is attractive to swapping engines and transmissions. It also allows a removable bell housing from another manufacturer to be adapted to the C4 main case without using the front pump bolts for mounting.
For the TH350, adapting to another non-gm manufacturer is more difficult due to the integral bell housing, especially with older engines having integral bell housings.
As far as comparison to each other in durability and performance, well I have had both and like the TH350 in stock form over the C4, but not by much.

 

Cutting the bell on a T350 is no hill for a stepper. The C4 bolts on like a hydro or a transmission. The cut T350 bolts to the front pump. I cannot say that the way the T350 bolts up is a real issue but the C4 is manufactured to be that way. So changing the bell is a mod but it does not change the engineers original design.

The C4 is versatile but you have to remember as they came from the factory they are not built to handle heavy torque loads. So if you have a motor that delivers you have to do more then just change the bell. I mentioned earlier that they C4 has plenty of aftermarket support so making one handle a load is not big deal but it is something that you should keep in mind if you are going to play. Like cutting the bell no hill for a stepper. The expense may make that hill more of a cliff.

 

Sometimes they almost remove themselves

 

LOL I exploded a TCI T 350 @40MPH in 97. The bell was spiderwebbed. A miner tap with a ball peen removed it.

 

Damn what a great thread.

That's me.

Amen, brother. Not what Hambers like to hear, but there it is.

 

Reason I never gave c4s much thought is when I was younger I saw a lot more c4s fail than th350s......not even adjusting for how many c4s vehicles there were compared to th350 cars ......there were easily four times as many th350 vehicles around yet the actual number of c4s failures was higher. And the c4s failures were generally in much lower power applications

 

Coming from the “ Chevy” pope” it’s hard to give your response any credibility.

 

I used a Flat O products kit to mount the C4 behind my Y Block in my 26 RPU.

It’s a nice compact little transmission for a small car like my 26T.

 

Considering back then I was actually neutral on brands and stuff like what I mentioned in my comment is what pushed me hard into the gm camp lol. I mean he'll my step grandpa killed both the original c4 and the rebuilt c4s he had in his 83 f150 with the dog factory 3.8 V6 it had lol. Keep in mind when I first started noticing c4s failures I personally had a mustang I was driving

 

I think just about any product, motor, trans, etc made by any manufacturer can be made better, just depends on what your plans are for the vehicle and how much you want to spend.

I also think that there are many trans options out there all made by different manufacturers that do the job quite well, we have the t400, c6, 727, all do their job as intended, it's when WE expect them to do more than intended that the aftermarket comes into play and then it depends on how much we want to spend.

So with the c4 if the aftermarket supplies parts that make it a formidable trans and it has the features you need or like I say Go For It !!

As far as price this is where I call stupidity, guys brag about 12,000.00 dollar paint jobs, 8,000.00 dollar interiors then the only reason they chose a sbc is because "they're cheap", really?? That's the excuse?

If I had that much money in paint and interior in my car it'd have a 392 hemi in it and not because it was "cheap" but because it's awesome! Or maybe the beauty of a 425 nail head! But "cheap" would never be part of the equation.....

...

 

Having owned about 40-50 “old” Fords I have yet to have an automatic transmission failure. C6 C4 Fordomatic Cruisomatic. I had one 1965 Galaxie wagon I bought cheap and it didn’t have any reverse gear and that was it. Maybe I was just lucky.

 

I think this post loses the point of this thread entirely.

This discussion is based on quantitative/objective reasons as to why the C4 is a good transmission that maybe could or should be used more frequently. Your comments regarding money further solidify this point. If money is no object, why are not more folks considering the C4 as a viable option, even with more expensive aftermarket support? Based on this discussion, it seems that the C4 is a perfectly good, albeit overlooked choice with some unique features that make it a good alternative to the TH350.

And FWIW, there is a substantial difference between "cheap" and "less expensive". Cheap is finding a $50 C4 on FB marketplace and sticking it in your car in the hopes it works. Less expensive is buying a new TCI Streetfighter C4 from Jeg's for $1900 with a warranty.

I'd also like to know where I can find one of these $12K paint jobs you speak of that are good enough to brag about.

 

With my discount on supplies and paint I'm sure I could be talked into doing one on something cool as it is I get stuck painting boring modern regular traffic most of the time..... usually farm vehicles lol

 

One thing being missed here is comparing the C4 vs the TH350 is apples and oranges. The C4 was developed as Ford's light duty automatic, with the FMX being the medium duty box and the C6 for heavy duty applications. Over at GM, the Powerglide was the light duty offering, the TH350 was for medium duty and the TH400 was the heavy duty version. Ford limited the C4 to 302 cubic inches or less (yeah, they did use it behind some larger motor a few times but never for long) as a general rule and it usually performed just fine in those applications (notably, not so good in trucks but they were chasing fuel economy). With that said, upgrades for more torque/HP are readily available and will give you a better street trans compared to a 'glide modified to the same levels. Its compact size, three speeds, light weight and low internal drag should make it a very viable choice. The removable bell is the cherry on top...

When Ford was developing the AOD, they bypassed the C4 and used the FMX architecture for a more robust trans.

 

Another thing worth mentioning has anybody explored the possibility of using an aluminum Cruisomatic/FMX FE bell as a lo-buck C4 adaptor? Also a removable bell, and not many people want them. Finding one may be a bit tough, but they're still out there if you look. Some machine work would definitely be needed...

I've also been mulling looking at those as a lighter-weight manual bell option if using a TKO/TKX... particularly if contemplating a hydraulic throwout bearing. Wouldn't be legal for racing but would knock another 30+ lbs off a FE install. To my knowledge, Ford never made a aluminum manual bell for the FE, all of them were cast iron.

 

Two things here.

I've always worked under the assumption that the AOD was a weak transmission, especially since O/T Mustang guys usually get rid of them in lieu of a C4. Maybe that's an incorrect assumption on my part. Maybe the AOD is stronger in stock form than the C4, but the modified C4 is stronger than the stock AOD.

The other thing I'd comment on is the C4 as a light duty transmission. I personally wasn't really aware of the distinction within Ford ranks but it totally makes sense. But that being said, for many of us but not all, a light duty transmission is suited just fine to achieve the goals we want to accomplish. Someone I know has the motto for their business, "when only the best will do." Well, for myself and I'm sure many other, "Totally mediocre but functioning properly" is perfectly acceptable when all you want is to drive your car without abusing it and log miles reliably. The Powerglide is a perfect example. How many tens of thousands of reliable miles have folks logged with a Powerglide? Maybe that's a good analogy, the C4 is a Powerglide with an extra gear.

 

A guy I know using one basically said the same thing about the C4. It’s a 3 speed PG

The folks I know using newer OT engines that use older non OD or non-computer controlled transmissions do so because they don’t need OD at the track and many run carbs on the EFI engines. So no computer.

 

One thing I know for certain the C-4 when built correctly will work extremely well. My personal experience using the C-4 behind our Ford flathead race engine's we have set many Land records at speeds over 200 MPH.

Our top speed record with the C-4 powered by an ARDUN overhead valve conversion on a Ford flathead at Bonneville is 225 MPH. This record is driving the car off the line on the salt and setting the record at the third mile. At the Loring Timing Associations event in Maine top speed at the mile and a half from a standing start our top speed record is 229 MPH. Yep the C-4 is a pretty good transmission for sure the way I see it.
Ronnieroadster

 

I’ve beet both the FMX and the C4 transmissions over the years without fail but when using the C4 needs a shift kit and adjustable vacuum modulator for any performance usage. The best years to look for are 71 to 80.

 

There are C4’s that do not have removable bell housings. There are plate adapters for those that don’t. I was looking to use a Flat-0 equipped C4 behind my 56 YBlock when a 62 Cruise-0 with a vacuum modulator became available. I’ll never hurt it for sure.

 

As a fan of the C4 I can say that they are not as popular as they should be. Shev oh lay crowd never had any reason to look at them, they had perfectly good options that bolted up. The early C4s were wonky, many with oddball valve bodies/shift pattern. Green dot anyone? And as has been pointed out, they were introduced as Ferd's light duty tranny. In the era of the C6, most performance seeking blue oval types opted for the C6. The FMX with its fantastically heavy cast iron body was not seen as a great transmission for anything but a heavy car. Even though it could hold up to a lot of torque.
Then, the Fox body 5.0 era came and drag racing the cars frequently meant searching for a better drag racing box. The C4 replaced the AOD in a million 5.0 Mustangs. Drag racing circles (not far and wide) but in certain areas and among some transmission builders really took on the C4. It is easily built by anybody to stand up to big power. They are drop dead simple and the old FordMuscle Forum had a ton of guys running C4s.
With my journalism degree, I thought I'd start a C4 thread to end all C4 "how to build" threads. I asked question after question and got guys from all over the US and even Aus to offer up how they built their C4s. There were bits and pieces littered all over the internet. Burly4x4.com had a good build, an Australian magazine had another. So I just asked question after question and the thread went on an on. But it was all over the place. While traveling on business I grabbed all the bits and pieces and put them into one "Monster C4 Thread" and it has almost 200,000 views. If you want to read it, it's long. Almost 8,000 words. It is still live and accumulating views at https://www.fordmuscleforums.com/threads/monster-c4-thread-text-edited-way-long-version2.416584/
Unfortunately that was 20 friggin years ago and many of the links inside that article are dead. Nevertheless, there is a lot of good information there. Read it thoroughly and you will get a great idea of the specific builds of many of the strong C4s built to stand up to big block drag motor power.
There are many different avenues and recipes therein.
One key point is that rollerizing a C4 (putting C6 and TH350 rollers in place of the thrust bushings) is not a big deal. I did it and I'm a shade tree mechanic. Putting a C6 roller bearing in the #9 location (farthest rear) is the most important. Because under load the gear train is thrust rearward and if you have enough power it'll shear the tangs off the thrust bushing and put metal throughout the trans.
I have some of the info from the dead links, like the Burly4x4 repro of a SuperFord valve body article. 5 different DIY valve body mods, plus a servo mod piece - if people want that info I can post it somewhere here, maybe in my profile page photos.
Peace

 

Thanks, Paul.

 

I’d like the recipe. Post it here or message me.
I’ve a C4 that will be used behind a mild 302. The engine/trans had little to no maintenance in the 30 years of use. May as well tell the shop what I’d like done.

 

Fantastic post and information, Paul. Tremendous contribution to this discussion.

 

The last link is still active. I assumed they were both dead.
Gotta lot of reading to do!

 

The AOD has a major issue with its input shaft(s). It has two, a larger hollow shaft and a smaller inner shaft that runs inside the outer one. I don't recall the arrangement of which shaft does what, but that inner shaft will shear off under big power. There supposedly is a fix with a slightly larger diameter and a better, tougher grade of steel used to make it. The AOD is also considerably more complicated compared to the C4 so isn't as user-friendly or as cheap to beef up.

 

Hey Budget36, thanks for the interest. I went back (it had been a loooong time) and the Burly4x4.com piece is just valve body mod options. 5 ways to build a valve body.
From the article itself, your build recipe should be drop dead easy...quality rebuild kit, maybe a TransGo shift kit and you are done.

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3 - Build level suggestions
What would I want to do to a C4 to get it to propel my dedicated 2500lb bracket car with a 250 HP carbureted motor to the lowest E.T.s? 89C - 250HP in 2500# car only requires a good working V-8 C-4 which would work great stock or with a shift kit. No other mods needed. RC – How to squeeze some ET by modding his C4? 89C - A full manual valve body is going to bump up the line pressure considerably, which takes power from the engine to do. No need to spend a lot of money on a trans that will already hold up to 250HP. The governor assembly doesn't add significant weight to the reciprocating assembly and doesn't use any power. About the only way you will reduce parasitic drag in the C-4 is to completely convert it to a full roller, which is expensive for the small ET gain and not needed unless you plan on having 600+HP.
JJ - On a mild, say 350HP, or under application would a good rebuild using 5 Red Eagle or similar clutches in the forward pack and 4 in the high/reverse pack be OK?
W8 – Yes, for a mild motor that would hold up fine.

 

Paul, with your previous research, what mods would you suggest for an engine that
makes alot more torque than the little Fords ?