Adding a friction and steel by eliminating Bellville spring

[F100builder]

I've been all over the net and have seen that some are eliminating the Bellville spring from their C6's forward drum in order to add one more friction and steel. I've also seen where a few of these springs have failed and broken into several pieces. I'm pretty certain that this is quite uncommon but it's got me thinking about leaving mine out and adding the extra clutch. Have any of you heard of or performed this? I assume that the beveled forward pressure plate would then just rest against the piston like the spring had? Next, will the empty snap ring groove be problematic? Will a friction or steel get caught in it?

If I do this, I will of course make sure the pressure plate-to-snap ring clearance is within spec.

[F100builder]

Well, answered one of my questions...I mocked it up and without the Bellville spring, the forward pressure plate covers the snap ring groove so there's no worries there. Now, just wondering about the actual elimination of the spring to go from 5 to 6 clutches.

[fordman]

one thing i do know. is that the forward drums are set up for cars and trucks to use different amounts of clutches in the packs. truck drums will use more packs than cars. is it possible you have a car transmission? maybe you could get the truck drum and use it.

[F100builder]

It's a truck drum for sure...the ID tag says, 'PGB-AK2' which is a 1970 F100-350 w/ 360ci and it has the cast iron tail with the yoke. It already has 5 clutches in it and I was just thinking about eliminating the Bellville spring and gaining a 6th clutch. I've seen several C6's with 4 clutch drums and they've typically been car C6's. The car C6's with more clutches as well as the 'R' servo usually were behind a 428CJ or something like that.

[fordman]

ok for some reason i was thinking cars had 5 and trucks had 7 clutches.

[papabug71]

Patrick, do you have a youtube account? If so, send a PM to this guy. I spoke to him a while back about the C6 when I was contemplating putting one behind my 302. He is very keen on the C6 & should be able to help you out.
http://www.youtube.com/watch?v=PMRhJFR_TrU

[F100builder]

Patrick, do you have a youtube account? If so, send a PM to this guy. I spoke to him a while back about the C6 when I was contemplating putting one behind my 302. He is very keen on the C6 & should be able to help you out.
http://www.youtube.com/watch?v=PMRhJFR_TrU

Thanks for the link...I can't remember if I do or not. If I do, I'd have to get my username and password again. I don't ever do anything but WATCH youtube vids.

I've also heard that people have disassembled C6's and have had NO Bellville spring in it to begin with. I've got to wait for a new one-way roller clutch and a set of thrust washers to be delivered before I can proceed so I have 2 or 3 days to continue my research. I've already built up the drum without the spring and with an extra clutch and it measures within spec. I'll continue building up all of the sub-assemblies and make a call or two if I have to before I decide. It's easy enough to pull a snap ring and throw the spring in at the last minute. I'm wrapping all the completed assemblies in plastic to keep the dust/dirt out of the oiled up parts (and to keep ATF from dripping all over)!

[basketcase0302]

Patrick,

I did have this done to my old style Bronco's C-4 many years ago. I'd say try to find an old school tranny tech and he'd be able to confirm.

[BobbyFord]

Patrick,
I sent you some links that may help. Also, I've done a little research and found that some people machine a step into the clutch pack pressure plate allowing more room in the drum.

[F100builder]

Thanks guys! I was actually hoping to avoid buying new parts or paying for machine work. Basketcase, I may just try and find a 'C6 guy' locally and pick his brain or even call the guys at Broader or C6-C4.com. They offer drums that accept more clutches and the prices aren't too crazy but I still didn't want to buy parts that I don't really NEED.

BTW...if anyone is interested, here are some links for your viewing pleasure:

Broader Performance http://www.broaderperformance.com/en/

C6-C4.com; The Ultimate C6 / C4 Performance Transmission Website http://www.c6-c4.com/

[averagef250]

Not directly related to your question... But, I used to believe adding as many clutches to get as much surface area as possible was the way to fly with autos. I didn't have the time to do the auto tranny builds for our vehicles anymore, just switched to buying ones from whoever had the best reputation for the one I needed. The thing I noticed about the high buck autos we've been using for awhile is the builders generally don't try to stack as many clutches in as possible as even just a few clutches will hold extroardinary power when everything's working right. I'm amazed at the power a stock clutched auto can hold when the hydraulics work right! Just saying I think the real secrets to auto builds are in thorough air checks, getting clearances/fits just right and dyno testing by someone who really knows that particular transmission.

[Donnie]

You can also use a beveled pressure plate on top of the pack or as someone else said , have the top plate machined to allow more space.. Using a pressure plate on top, you will risk breakage if your garage shifts are firm.......Remember, the snap rings are selectable also to set your clutch clearance..The foreward clutch is usually not a problem, it is getting a good 3rd that is more difficult........Donnie