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FE Power Forums => FE Technical Forum => Topic started by: CV355 on January 14, 2020, 09:18:50 AM

Title: Who is the "authority" on C6s?
Post by: CV355 on January 14, 2020, 09:18:50 AM
While pulling the engine and trans from my '69 Mach 1 this past weekend, we discovered that the transmission case was cracked in 2 places, damage at the tailshaft, and some of the fitting threads were worn thin.  I was planning on sending the transmission to be rebuilt, but these findings make me want to just scrap it.  So, I'll be in the market for a built C6- what company should I be looking at?  I used to use Lentech for 4R70Ws, but they don't work on C6s. 

PATransmissions and TCI are the first that come to mind, but I'd like to know what you guys recommend.  Anybody else I should consider? 
Title: Re: Who is the "authority" on C6s?
Post by: jayb on January 14, 2020, 10:31:12 AM
I don't know who does C-6s, but I'd like to suggest that you switch to a C-4 instead.  You will pick up quite a bit of power at the rear wheels with that swap, because the C-4 takes a lot less power to run than a C-6.  When I replace the C-6 in my Mach 1 with a C-4, it felt like somebody had released the emergency brake.  Big, big difference.  Performance Automatics makes a good C-4 and the adapter bellhousing for the FE.
Title: Re: Who is the "authority" on C6s?
Post by: thatdarncat on January 14, 2020, 10:32:52 AM
You might want to let people know what area you are in, since shipping cost could be a concern, and someone might know a good local builder near you. C6’s are pretty easy to rebuild, you may even want to consider doing it yourself. Our member Drew P. put a C6 build post together, I think on Facebook, a while ago, maybe he can link it. In any case, it’s something a competent local builder can do, but I understand they’re getting harder to find, especially on older transmissions.

I haven’t used them to build a transmission ( I do my own ), but Broader Performance seems to have an excellent reputation for Ford automatics. They’re in Texas, here’s a link:

https://broaderperformance.com/

Joel’s on Joy in Michigan has a good reputation on Ford racing automatics, I think they still build the transmissions for the new Cobra Jet Mustangs for Ford, I’m not sure if they do regular rebuilds or not.

Title: Re: Who is the "authority" on C6s?
Post by: CV355 on January 14, 2020, 10:36:30 AM
I don't know who does C-6s, but I'd like to suggest that you switch to a C-4 instead.  You will pick up quite a bit of power at the rear wheels with that swap, because the C-4 takes a lot less power to run than a C-6.  When I replace the C-6 in my Mach 1 with a C-4, it felt like somebody had released the emergency brake.  Big, big difference.  Performance Automatics makes a good C-4 and the adapter bellhousing for the FE.

Interesting... I had not considered that!

You might want to let people know what area you are in, since shipping cost could be a concern, and someone might know a good local builder near you. C6’s are pretty easy to rebuild, you may even want to consider doing it yourself. Our member Drew P. put a C6 build post together, I think on Facebook, a while ago, maybe he can link it. In any case, it’s something a competent local builder can do, but I understand they’re getting harder to find, especially on older transmissions.

I haven’t used them to build a transmission ( I do my own ), but Broader Performance seems to have an excellent reputation for Ford automatics. They’re in Texas, here’s a link:

https://broaderperformance.com/

Joel’s on Joy in Michigan has a good reputation on Ford racing automatics, I think they still build the transmissions for the new Cobra Jet Mustangs for Ford, I’m not sure if they do regular rebuilds or not.

I'm in the Greenville SC area.  My C6 would not be re-buildable given the damage to the case, so I'm assuming it'll be far more cost effective to just get a new one.  Someday, I'd like to learn how to service the transmission, but I don't think it's in the cards for this phase.

I appreciate the references!
Title: Re: Who is the "authority" on C6s?
Post by: gt350hr on January 14, 2020, 10:37:29 AM
   Frank Merkle does a good job on C6s.
Title: Re: Who is the "authority" on C6s?
Post by: Gregg on January 14, 2020, 12:03:06 PM
I'm very happy with my Broader C-6.  I have a mild street only 390 in a '64 Galaxie.  I went with the wide ratio gear option, stage 4 shift and about 2000 - 2200 stall converter.  I thought about a C-4 or AOD, but for my use I just couldn't justify the cost.
Title: Re: Who is the "authority" on C6s?
Post by: Pentroof on January 14, 2020, 07:44:34 PM
I can’t recommend TCI. I bought a “street rodder” C6 package from them and it has leaked from day 1...and not just a little
Title: Re: Who is the "authority" on C6s?
Post by: aj on January 14, 2020, 10:29:03 PM
+1 for Broader Transmission.  I’ve visited his (Jay’s his name)  shop several times and can attest that he’s a craftsman and builds every tranny himself.  One man show with a very well equipped shop (CNC, tranny dyno, etc).   Focuses primarily on C4 and C6 only.  Good guy.  He’s typically hit his hands in a tranny or dyno so leave message if he doesn’t answer but he’ll call back .
Title: Re: Who is the "authority" on C6s?
Post by: KMcCullah on January 14, 2020, 11:03:09 PM
Jay Broader gets my vote. His .400 Pro Tree C6 valve body is the real deal. I've called him several times when I needed advice with several C6 builds. Super nice guy.
Title: Re: Who is the "authority" on C6s?
Post by: 338Raptor on January 15, 2020, 01:30:15 AM
I’ve purchased performance C6 parts from Broader and he’s given me some good advise. All his advise and parts have help up well behind my 900 hp mud truck engine.

I’ll second the “do it yourself” advise. The C6 is easy to build.
Title: Re: Who is the "authority" on C6s?
Post by: CV355 on January 15, 2020, 08:08:51 AM
I appreciate all the feedback!  I'll definitely be calling Broader.
Title: Re: Who is the "authority" on C6s?
Post by: babybolt on January 15, 2020, 08:35:27 AM
I've had a couple of FE C6 cases that were cracked.  Its something to look for when buying one.  Saw one that had been "pre-welded" by the re-builder.
Title: Re: Who is the "authority" on C6s?
Post by: Jim Comet on January 15, 2020, 08:50:34 AM
I rebuilt my C6 with the help of Kevin (thatdarncat). I did all the work with Kevin watching and so far it made it through 1 season running high 10's. I took a lot of pictures when disassembling the trans and that helped. My trans had been set up fully rollerised during a previous build so I just made sure my final clearances matched what they were before I disassembled it. My front clutch had been machined to accept a roller bearing so I sent it to Broader and he installed an extra clutch and set the clearance on that for me. I also installed his shift kit and it works great. I definitely would recommend Broader. Jim
Title: Re: Who is the "authority" on C6s?
Post by: CV355 on January 15, 2020, 01:17:31 PM
I've had a couple of FE C6 cases that were cracked.  Its something to look for when buying one.  Saw one that had been "pre-welded" by the re-builder.

Someone snapped off one of the bolt tabs around the bellhousing, and there was a pronounced crack down near where the tailshaft attaches, but it did not leak (yet).  The guess is that the top bolt was torqued before the rest, and the torquing motion snapped the tab off. 

I've encountered so many head-scratching things while disassembling this car that I can't trust anything without a full disassembly.  The restoration work done by the previous owner was excellent, so the car has a solid foundation.  But, some of the work done by shops was laughable at best, so we're trying to fix it all in one swoop.   
Title: Re: Who is the "authority" on C6s?
Post by: fryedaddy on January 15, 2020, 10:20:13 PM
i must have got a good one.i have been trying to tear my c6 up since 1986.my comet was a factory 4 speed car.a buddy talked me into putting a c6 in it in 1984.after a couple years i got to missing my 4 speed so i told everybody i was putting a 4 speed back in as soon as the c6 tears up or starts slipping.36 years and 2 engines later its still shifting and performing like a dream!i bet its done a thousand burnouts and made hundreds of passes and several thousand street miles.i hope it goes out before i die.
Title: Re: Who is the "authority" on C6s?
Post by: cammerfe on January 15, 2020, 10:54:47 PM
Originally, C6 transmissions as factory designed, had a lot of extra drag inside, due to 'solid' thrust washers. When assembled with the latest rollerizing, including the proper clearances, they do much better. A C4 will do better yet since the parts are smaller and, therefore, have less mass to move internally. It's said that the upper limit for a C4 is somewhere in the range of 1K HP---or actually the torque that is what you get that goes with the 1000 HP.

Years ago, I was involved in the weekly rebuilding of the C4s Doug Nash used in his 'Bronco Buster' fuel funny car. It had an aluminum chassis and body, so it weighed practically nothing, and ran a small block on 'pop'. The transmissions were ready for rebuild after only a couple passes at most. He usually expected to change out the trans about three or four times during a weekend's racing. Better parts and other improvements would probably mean that today you'd get, perhaps, half-a-dozen passes before needing to change under the same conditions.

KS

KS
Title: Re: Who is the "authority" on C6s?
Post by: RustyCrankshaft on January 16, 2020, 12:48:01 AM
I've had a couple of FE C6 cases that were cracked.  Its something to look for when buying one.  Saw one that had been "pre-welded" by the re-builder.

Depending on how/where they're cracked I've stitched them up before to save the case. I have done the same on a TON of Allison cases, most I can save. It can be a tedious process however. I have had way better results stitching transmission cases than I have welding them.

Personally I think weight has as much to do with HP. If it's a truck/heavy car, etc. a C6 will hold up better, but you do pay a penalty for it. As was mentioned, a full rollerized build does a LOT to reduce friction and drag losses. I like C6's for non-competition use - I'll trade a little bit of HP loss to gain longevity. If it isn't a race car I want to build it once and drive the wheels off it. If I'm racing it I've already accepted I'll have to refresh stuff and it's coming apart on a "regular" basis.
Title: Re: Who is the "authority" on C6s?
Post by: thatdarncat on January 16, 2020, 05:13:39 PM
Just a thought, is your current C6 the original one for your Mach 1? If it is, it should have the partial VIN stamped on it to match your car. I understand your desire to get a replacement to get your car back running, but you might want to hang on to original to keep with the vehicle for the future. If it’s already been replaced then you can ignore this, but I just wanted to mention it because not everyone realizes about the VIN stamping.
Title: Re: Who is the "authority" on C6s?
Post by: 66FAIRLANE on January 16, 2020, 05:17:03 PM
Anyone measured how many HP rollerization frees up? If not, educated guesses?
Title: Re: Who is the "authority" on C6s?
Post by: jmlay on January 16, 2020, 08:39:06 PM
I found this interesting reading:

https://www.fordforumsonline.com/threads/1966-ltd-resto-mod-thread.14264/page-2#post-77070

https://www.fordmuscleforums.com/threads/1966-c6-build-rollerization-part-2-modification.610433/

https://www.fordmuscleforums.com/threads/1966-c6-build-rollerization-part-3-assembly.610465

https://www.460ford.com/threads/roller-c6-is-it-worth-it.105633/
Title: Re: Who is the "authority" on C6s?
Post by: RustyCrankshaft on January 16, 2020, 09:50:12 PM
Anyone measured how many HP rollerization frees up? If not, educated guesses?

Not apples to apples because I've never done a back to back test with a C6. I did with another model of transmission from the "other brand" when I was rebuilding the trans dyno at a friends place some years ago. I was trying to see what I could get the repeatable resolution down to. Back to back test with the same trans, just a swap from thrust washers to torrington's showed about a 15hp difference at 350hp (dyno was powered by a 350hp 8v71TA and I swapped the hydraulic absorber for a Telma retarder). I would expect a C6 to be in the ball park.

This was more about messing around with building the dyno rather than a specific test of the trans so results may vary. However, it was a repeatable and noticeable difference and verified with a LOT of pulls over several weeks. But again, this may not be the average results of rollerizing and that isn't what I set out to discover so take it all with a grain of interwebs salt.

Only thing I couldn't do was run it long enough for sustained load testing. At full load the engine would get hot after about 20 minutes-had a bad block which is why it ended up on the dyno in the first place. But worked fine for that application.
Title: Re: Who is the "authority" on C6s?
Post by: gt350hr on January 17, 2020, 10:40:46 AM
  I have a rollerized C4 ( PA parts) that I built. No change in ET that I could prove, Also just finished building myself a wide ratio full roller C6. YES the effort to turn it went way down!
   Randy
Title: Re: Who is the "authority" on C6s?
Post by: CV355 on January 17, 2020, 11:20:58 AM
Just a thought, is your current C6 the original one for your Mach 1? If it is, it should have the partial VIN stamped on it to match your car. I understand your desire to get a replacement to get your car back running, but you might want to hang on to original to keep with the vehicle for the future. If it’s already been replaced then you can ignore this, but I just wanted to mention it because not everyone realizes about the VIN stamping.

I can check.  I have not scrapped anything at all, and I plan to keep all of the take-off parts in storage just in case I get the itch to do a concourse restore someday, or if I have to part with the car for some unforeseen reason and a future buyer wants original parts.
Title: Re: Who is the "authority" on C6s?
Post by: e philpott on January 17, 2020, 12:31:31 PM
I have rollerized mine but have no data to support any conclusion , C6's have a heavy drum that spins up in first gear but has to stop for second gear , to make third gear the band has lets go of the drum and the direct clutch has to spin the drum back up to speed for third gear . At some point you might need the strength of a C6 or if you're not chasing every ounce of ET a C6 is a good choice , but the shear weight of the C6 Drum and having to stop all that weight just to turn around to spin it back up I just can't see a C6 keeping pace with a C4 despite the C6 being rollerized
Title: Re: Who is the "authority" on C6s?
Post by: thatdarncat on January 17, 2020, 01:28:15 PM
Just a thought, is your current C6 the original one for your Mach 1? If it is, it should have the partial VIN stamped on it to match your car. I understand your desire to get a replacement to get your car back running, but you might want to hang on to original to keep with the vehicle for the future. If it’s already been replaced then you can ignore this, but I just wanted to mention it because not everyone realizes about the VIN stamping.

I can check.  I have not scrapped anything at all, and I plan to keep all of the take-off parts in storage just in case I get the itch to do a concourse restore someday, or if I have to part with the car for some unforeseen reason and a future buyer wants original parts.

Here’s a few examples. Usually stamped on the flat pad near the tailshaft. Sometimes distinct, sometimes faint. In general it applies to 1968 model years & later cars in our FE era.

(https://i.postimg.cc/G2htcp67/3-F51-E251-4-D4-A-429-D-A989-5-E0-A808-FD707.jpg) (https://postimg.cc/QBwhmj81)

(https://i.postimg.cc/PfCZZ6F6/F09-A74-FB-9127-4353-841-F-0-E7-C81029-A73.jpg) (https://postimg.cc/K4yRh5bL)

(https://i.postimg.cc/xCwdLPc7/90-EAE273-417-E-4-E73-8-B22-DC7-CFD1323-C6.jpg) (https://postimg.cc/LYVRpLkB)
Title: Re: Who is the "authority" on C6s?
Post by: Gaugster on January 18, 2020, 10:42:21 PM
I don't know who does C-6s, but I'd like to suggest that you switch to a C-4 instead.  You will pick up quite a bit of power at the rear wheels with that swap, because the C-4 takes a lot less power to run than a C-6.  When I replace the C-6 in my Mach 1 with a C-4, it felt like somebody had released the emergency brake.  Big, big difference.  Performance Automatics makes a good C-4 and the adapter bellhousing for the FE.
This is good to know. The C6 in my Cougar is acting funny and I had planned on a rebuild or replace with a more stout C-6. It was previously fitted with a steeper 1st gear ratio. So a C-4 can be made just as strong and more efficient? Did any of the transmission gear ratios change as a result of the swap to the C-4? I'm guessing the C-4 is overall less weight too?
Title: Re: Who is the "authority" on C6s?
Post by: thatdarncat on January 19, 2020, 12:36:32 AM
Both the C4 & the C6 have the same stock gear ratios - 2.46:1 / 1.46:1 / 1.00:1. The aftermarket makes “wide ratio” gear kits for both transmissions, I’m not sure off hand if they are the same ratio or not, but they’re probably close. I have couple C6’s with the Ford Motorsports wide ratio kits, they are 2.72:1 / 1.54:1 / 1.00:1 ratio. I don’t have the actual transmission weight on hand, but yes, the C4 will be considerably lighter. The main thing for making the swap to a C4 for a FE is you need to buy the adapter bellhousing, and they’re not cheap. I think you have three choices for adapter bellhousings, Performance Automatic makes one, Quick Time makes one, they are both SFI certified, which is good if you’re racing at a quick enough ET that you need the SFI certification. JPT used to make an adapter bellhousing too, but I think he may have retired. Used JPT bellhousings turn up for sale occasionally. I think JPT might have been the first to make a commercially available FE to C4 bellhousing. And of course the C4 is shorter, so you will need a new driveshaft too if you are changing from a C6. The C4 uses a smaller input & output shaft. They make stronger C4 input shafts, they are probably a good idea for a healthy FE. I have a friend who snapped a stock C4 input shaft last summer with a 700hp Windsor in his race car, I would think by at least 600hp a person should be looking at the stronger aftermarket C4 input shaft.
Title: Re: Who is the "authority" on C6s?
Post by: winr1 on January 19, 2020, 02:09:42 AM
Weighed a C4 an C6 .. no fluid, no convertor .. C6 was 30 lbs heavier

12" C6 convertor would add a bit of weight

JPT C4 to FE bell is for pan fill C4 only.... Jim sold the last bunch to Jessie Holmes IIRC

I have one I bought through the forum but not directly, it has been welded an machined to accept an FE 184 tooth auto flywheel



Ricky.
Title: Not a fan of the C6
Post by: Dr Mabuse on January 19, 2020, 11:01:38 PM
For what it's worth (of course, your results may vary), over the years, I have had six C6's fail on me.

The 4R70W  in my 2003 Marauder has lasted well over 100K miles, and the 4R75W in my 2009 Crown Victoria also has (probably - bought it used) 100K+ miles on it. The 4R75W in my 2000 Crown Vic PI was rebuilt just before I bought it, has 165K on the chassis, but the prior owner had supercharged it with 17 lbs of boost and over 600 rwhp (before the 4R70W trans failed).

I like Jay's recommendation of using a C4. Broader says their C4 can handle ~800 hp, and Performance Automatic claim 1,000 hp capacity, with a lifetime warranty and rebuilding program.
Title: C4 to FE bellhousing
Post by: Val406 on January 19, 2020, 11:10:22 PM
Over on the other forum (fordfe.com), there is currently one listed for sale. Looks new and a great price. Not mine.

https://www.fordfe.com/pa-fe-bellhousing-t163917.html
Title: Re: C4 to FE bellhousing
Post by: thatdarncat on January 20, 2020, 01:15:04 AM
Over on the other forum (fordfe.com), there is currently one listed for sale. Looks new and a great price. Not mine.

https://www.fordfe.com/pa-fe-bellhousing-t163917.html

Here are a couple pictures of what the current Performance Automatic PA26390 FE to C4 bellhousing looks like, which fits the case fill C4. It’s obviously different, so anyone interested should probably double check with Performance Automatic on what transmission the one on the other forum fits. It is a good price, but I’d hate to see someone surprised.

(https://i.postimg.cc/d32vRQm8/2-AE88893-0-CAD-412-E-B36-C-9-D873-B15-A069.jpg) (https://postimg.cc/MfphqSLT)

(https://i.postimg.cc/2jhzNTRV/D8-C38242-1-B8-D-4-EF5-A603-3217-E3-EE126-D.jpg) (https://postimg.cc/Z0Ykr8qS)
Title: Re: Who is the "authority" on C6s?
Post by: winr1 on January 20, 2020, 06:22:16 PM
The other bell may be for an AOD ..



Ricky.