Convertor swap and c6 build

Well I am retired now and started my first project .I am swapping out my 10" tci convertor for a 8" ati and going through my trans .To all that dont know my car is a 67 comet with 460 power .7.40 on a warm day in the 1/8 is my normal times .It has been 11.36 @118 in the 1/4 .On teardown just the normal clutch dust in the pan I freshened this trans. about 3-4 years ago .The high gear clutchs look good the plates show some spots though not really blue but probably some slippage .These were raybestos clutchs .My forward clutchs are the alto red and clutchs and steels are fine .My band is the old rigid wide band it hasnt been replaced in 5-6 years .The lining is getting thin so I will have it relined Probably with the red alto material .And the clutchs steels in the back for low gear look good also .My valvebody is one I built uo with a transgo kit 67-3 .It is forward pattern manual valve body .My plans are swap convertors and upgrade my third gear clutch drum .This trans. doesnt have a hard third gear shift .It shifts firm not hard .I have had two valve bodies on it and still no hard shift into third .So I purchased a drilled clutch drum from broader to see what effect this will have .I have swaped these before and it really tighened up my shift .I do have the r servo from sonnax and will be installing an ati input shaft .I will post up dates as I progress .Sorry for such a long post Doug

have you rollerized the c6 yet or planning on it?

Yes I am .I already have the#9 roller in there .I bought a reverse planetary gear it has two sets of rollers .I put the sun shell on it and it spun so much easier with the rollers no comparison .For now this is the only rollerizing my budget will allow .I also had time to compare my ati convertor to my reliable tci .Everything on the ati looks much better .The welding the studs for the flexplate The tci loks like it was built on an assembly line .Tha ati looks like one guy did all the work and he was proud of his craft .I did purchase an ati input shaft as well After breaking the input on my 427 street car I am "gun shy" so I bought one for my dragcar .I had to massage the splines where the shaft goes into the forward clutch drum .It is just a little tight and doesnt want to fully engage the drum .Some emery cloth and stroking it in and out and it goes in all the way now .I went to my local trans parts store TPU in conley Ga.They convinced me to use a flex band instead of having my hard band relined .I believe it is a sonnax .It has the red lining and is wider than my old hard band .I am going to try this but Somehow I have more confidence i n my hard band .What i dont like is the clips for the servo.Kinda puny compared to my old band .But I will see Thanks all more up dates coming Doug

Hey Doug,
When will you be going to Silver Dollar Raceway next? I have a goodie box of assorted C6 small parts in my stash that I would like to present to you...as a retirement gift. Various gaskets and stuff that I may never use again since swapping to a non-Ford 2-speed.
Keith

The divison finals are sept 30 and oct 1 .I might go to watch on the sept 30 date.But I plan on going thereto race on the 5-6 november for the finals .Thanks for the offer on the c6 parts very kind of you .Maybe I can buy you a death dog from the concession stand at reynolds .That race in nov is a good one maybe you can come down and thanks again sir Doug 678 603 8400

So I had to go to my machinist in mcdonough Steve at Dixie performance .He had to cut down my low reverse pressure plate so my clearances would be in the 050. neighborhood .After setting up my p.p. in his lathe with a dial indicator no cut the required amount off (.007) And I have .047 clearance snapring to p.p. .He has always been real good to me and did the machining on my 460 While there I got to see hear a stroker 427 ford engine run on their dyno 496 cubes 567 hp with more tuning to come .Being retired is nice Doug

Today I setup my clutch drums .My high gear drum or direct as some call it is one that I bought from Broader perf.It has the holes drilled in it for the fluid to disperse when you shift into high gear .After changing my steel plates and a different snap ring I had .052 clearace .I also filled all the holes with springs .Cleaned everything again put my seals on and assembled everything so I could air check it .The clutchs applied and come off but I heard an air leak .I did this again and found the source of my air leak .At the front part of the clutch drum there was a tiny hole drilled .If the trans. was assembled it would be facing the pump .I called jay at broader and he told me it was a .030 hole drilled to be an air bleed .He said no need for concern it shouldnt be a problem .I wonder if this is to help whenever you come out of third gear .And possibly to lube the front bushing .As long as he says it is ok it is ok with me .My next source of frustration was the pump gears .I had my new convertor on my bench so before installing the pump gears in my pump housing I decided to test fit them to my convertor .Well the inner pump gear that has the flats to engage the conv.wouldnt go over the flats on the conv..I had a small file and filed the gear on both flats and tryed it again still no go .My old pump gears fit fine .I miced both parts and they were the same dimension .My old gear that fit was .010 bigger than the conv.Monday I will take the new pump gears and my conv.To the trans part store to see whats up .Luckily I checked this before assembling everything .I would be blaming the conv .and trying to make something fit that wouldnt .More to come next week Doug

That bleed hole is to stop centrifugal apply as the drum spins in 1st gear

Before I forget thanks greg for explaining the bleed hole to me and others .I took my conv. and the new pump gears and my old one back to the trans. parts store .Well after opening two other packs of new pump gears none of them fit my ati conv. or one of there remans.My old pump gear fit their conv.and mine as well .They wouldnt say but after a bit they come back with a set of gears that fit perfectly .The quality on this set of gears was much nicer than either gear I had with me .The counter man wouldnt admit it but my gears were probably made in china .Well i figured that .It doesnt say it on the package but that is probably the case .The parts man said they have a have a hard time getting parts for older trans.Funny to me an aod takes the same gearset .Go figure.With the pump ready I could now check the endplay .Mine was tight at .008 I believe the spec is .008-.041 .I used apiece of glass as my flat plate and some 240 grit sandpaper with trans. fluid as lube to sand the copper side of my #1 bushing .This is the one at the pump to high gear drum .It took a couple of trys sanding the bushing and installing the pump in the trans.to check it .I expected this after I replaced my old reverse planetarys with its two bushings with the new one with rollers bearings from Broader perf..Got the flex band installed and the trans. is assembled .I forgot to mention my forward clutch drum I set the clearance to .031 It is a factory 5 plate without the lip seal .I am glad for this as I normally tear up at least one of those lip seals upon installation .Tell me what is the trick to this I am happy that the pump gear situation is over for me .I believe the trans. store is sending all those gears back .I wonder if they are going to china ??Thanks all more info later

This is what i use on those lip seals

Greg where did you get that tool from ? Did you get it at your trans parts supplier ? And can you explain the bleed hole a little more.I am an old dog but i want to learn more tricks.And do you think it is worthwhile to use a forward clutch drum with the lip seal ?Most of my c6s are older but several friends have newer versions with lip seals that is where i have had this situation come up .Thanks for your information and help Doug

manofmerc wrote:Greg where did you get that tool from ? Did you get it at your trans parts supplier ? And can you explain the bleed hole a little more.I am an old dog but i want to learn more tricks.And do you think it is worthwhile to use a forward clutch drum with the lip seal ?Most of my c6s are older but several friends have newer versions with lip seals that is where i have had this situation come up .Thanks for your information and help Doug

Doug i see those tool online for sale from some of the parts places . That is a pic i found online i posted for reference .
You can make one easy enough . I used a piece of 1/4" steel tube with mig welding wire loops each end and then squash the tube flat holds it in.. Works good can help feed the lip seal around without cutting it ..

I've used both types drum , the pistons are different for each seal so you need to use the correct seal for that piston. The lip seal pistons have an undercut on the lower land and the square cut seal type pistons have both lands the same .. The lip seal is the later type and possibly better but the square cut seals work ok too. Each type works ok IMO.

The bleed hole in the high/reverse drum is for if you are turning in excess off say 6000 RPM in first gear regularly. What happens in a stock drum is , in 1st gear the drum is spinning hard and any oil trapped within can be forced outwards and actually start to apply the piston and drags that high clutch pack when it shouldn't be and starts to toast the frictions .. The bleed is enough to stop that occuring. The hole is usually .030- .040 and drilled outwards in the lower corner of the drum. The small bleed is usually not enough of a leak to cause any issues with the pack applying . I like to only drill the drums when using manual valvebodies that run a higher line pressure .. Just to clarify the bleed hole i'm talking is right in the bottom of the drum underr where the piston sits .. AS OPPOSED to the holes that are normally drilled around the circumference of the drum where the band runs to release trapped oil from between each clutch plate

Greg thank you so much for taking the time to respond to my questions .It is sometimes difficult to find info on performance upgrades to older trans..Like i said I am an old dog still wanting to learn new tricks .One reason I am doing this upgrade to my trans. is my not being satisfied with my 2-3 shift .It shifts kinda firm but this is a drag car and I want a much firmer shift .One of the reasons I changed to the Broader drum .My valve body is one I built up with the transgo 67-3 shiftkit .This is their forward pattern full manual valvebody kit.I am pleased with this v.b. but still not to happy with the 2-3 shift .I had a tci street v.b. in this trans. for a long time and really it was about the same as the transgo .Talking with Jay at Broader he has been telling me to remove my 2-3 shift checkball from my v.b. .well I did this and everything in my v.b. looks clean and in good working order reassembled myv.b. installed it and the pan and got ready to install .This is the first time for me to use an ati convertor .I filled it with 1qt.of type f it took a minute but I got it splined up put on my trans. jack and went to work under the comet .The studs on my new conv.have spacers on them .Once i got my trans. bolted to the engine there was about a 3/16 gap flexplate to stud spacers .All I have ever heard of is dont tighten the conv.studs to much you will pull it out of the trans. pump .So I called ati.They said that was perfect .I guess that is how their conv. is made to fit .Well I tightened away and all is good .I still have some more work to do and I am going to makeup some header mufflers so I can get my car going without making my neighbors mad. And again thank you Gregaust fo rtaking the time to respond to my post .I am doing this posting to help other backyard transmisson builders .More updates later Doug

bleed holes on the direct or high /reverse drum is a carry over from the THM 400 with a poorly designed VB a C6 with proper clearances it is impossible for the direct clutch to apply dew to centrifugal apply of the 10 cc of fluid left in the drum behind the piston!!!!!as the drum would have to exceed 100,000 rpm to get close to clutch apply. a .030" bleed hole in the is good for burn clutches in high gear as it will reduce high gear apply with 180 line pressure to 120 at the clutch pack , and I have the fully gauged trans as do all the trans that leave my shop to prove it!!!
Frank

You're welcome Doug, i just try to help where i can.. I've never drilled a C6 drum.. I have done on C4's though that are going to see 7000+

Today I got the comet going I believe it takes 9 1/2 qts. of fluid to fill my trans. now with my smaller conv.I probably overfilled it by 1/2 qt. I had a small leak at my coolerline I tighten that up and all is good .I made me some header mufflers so my neighbors wont be mad with me .I had some collectors and two old dynomax mufflers a little cutting and welding and two collector mufflers for the price of two collector rings$24.95 at Barnett performance .My car is so quiet now I really should have done this before . My car is on jackstands with the jacks still under it front and rearI ran it through the gears all shift and reverse works as well .No more leaks so far .My complaint with this trans has been my 2-3 shift .So far on the jackstands only my 2-3 seems harder it might be different on the road but it really snaps into third .My 1-2 shift isnt the same as before it is firm but before it shifted hard in second .A little research is to be done there .I have the sonnax r servo I have had problems with the small o rings that go on the stem of the servo I put new ones on maybe one is torn .Or maybe it is my imagination I will see probably next week .After I got the comet going I looked under it for leaks i looked behind the mufflers and all this debris was under my car .Nuts twigs straw some creature was living in my old mufflers .I hope he got out alive idont need to be smelling any dead animal .Greg thanks again for your information and help .And the c6 guru mr.Frank.Thank you for taking the time to explain that bleed hole some more.Between Greg and mr.Frank you both taught me something .And really isnt that what all this is about Doug

Bit hard to tell how the shifts are on stands , be good to see on the road ,with the 2-3 checkball out that 2-3 should be pretty solid

As i stated in my previous posts i wasnt satisfied with my 2-3 shift .Well it is fine now .But i now am having a problem with my 1-2 shift .Before this refresh my 1-2 shift was hard and quick .It shifts but just firm not hard as before .I have had problems with the orings on the sonnax servos before .It is the two small ones on the stem of the servo .This same thing happened with this same trans before .And a buddy of mine had been doing a second gear burnout and his orings were torn .The band wouldnt fully apply he burnt his band and drum up .I was able to pull my servo out the small oring had a tear and I even found the small piece of oring .Now this is my fault not sonnax .But I have never had a problem with 1-2 shift with a stock ford servo .I dont think I would use the r servo on a stock rebuild for anyone other than myself .I have previously just used whatever oring would fit the servo .Sonnax uses a squared off oring with a cut in it .It is supposed to be easier to install .And by the way the sq cut oring is the first to go on it will be the first one to in the trans .After re installing this my 1-2 shift still isnt like before.So a little more research is in order .And to those that may not be familar most if not all these aftermarket r servos are made by sonnax .Will be back later .

Well i have been blaming my servo for my not so hard 1-2 shift .I dont believe that is my problem .I put my dragcar on the road today .My 1-2 shift isnt hard neither is my 2-3 shift .It shifts fine but not like it should .I drove around my neighborhood this am most people are at work and I had mufflers on so I brought my comet back in the shop .After letting it cool off I hooked a pressure gauge to the port on the drivers side .These are the readings from this same trans. about three years ago .P 140 R150 N140 D130 2 130 1 150 These are my current readings P150 R150 N150 D75 2 75 3 75 1 150 .With pressure low in my forward gears it must be a cut or pinched seal in either my forward or direct clutch drum .My trans .gotta come out :I screwed up something .The reason my shifts arent hard is there isnt enough pressure to make them that way .I should have put the gauge on it from the begining .Well Off to work on this bugger.Doug

WOW that's low , be interesting to see why ???

I pulled my c6 out and disasembled it I really dont see anything wrong .I put my forward clutch drum onto the pump so I can air check it and found nothing .I did the same with my direct or high gear clutch pack and no leaks either .But I noticed air leaking from where the stator bolts to the front pump .It was bubbling inthe trans.fluid .I poured more fluid around this area.1/3-1/2 around this pump to stator it is leaking .Two of the holes are for the forward and direct clutch packs the other is for the convertor I believe .It was leaking badly .I found another stator cleaned it replaced the sealing rings and with a flat piece of steel and 240 sand paper I sanded the backside of this stator .I put it together with some grade eight bolts then I pressure checked it like my old one .No leaks anywhere .My other stator must have some warpage to it .This has to be my problem I had 75 lbs.so it had some pressure but not enough to give a hard shift .It will be a few days before I can post again but I will be back and thanks again Greg for following my kinda long thread Doug

Well guys it hasnt been easy but I found my pressure problem .My pressures before replacing the stator .P140 R150 N140 D75 2 75 1 150 my pressures now P140 R250 N 140 D150 2 160 1 175 .I am beginning to wonder if my stator hasnt been leaking all along .My shifts are nice and firm with my2-3 being really hard .I may replace that 2-3 shift ball before it is over with .I just didnt think it was necessary to check the pump to stator for leakage .I know better now .My ati convertor makes this car feel like it has 50 lbs. more torque it is lose .I just hope my track will have a test and tune in oct.Thanks to you all Doug .I will report back with the convertor test whenever I can

That's great news .. I have seen some C4's with a little leakage there but never enough to lose that much presure .. Good find indeed to get it sorted ..

Finally made it to reynolds this is the lowdown on my c6s shifting .I really like the drilled broader clutch drum .My 2-3 shift is nice and hard snappy is a better word for it .I regret putting the flex band in it shifts ok but I liked my rigid band better .In the general discussion is the story on my 8" convertor .To much torque now my comet refuses to hook up .I left the line and it was like I was in the water box .I did get it to hook up once I had a 2' wheelie and 1.53 60 ft.My other 60ft. was 2.00 .Normally with my 10 conv.I would have a 1.61 60 ft.I will call ati this week to see what they say .Thanks to all that read my posting and that had suggestions when ever I had some problems .If i can get my traction issues solved maybe I can have a low 7 or high 6 second car .Doug

I have cured my traction problems from my convertor swap.And now I love my ati convertor .Over the winter I bought a set of cal tracs,mono leaf springs,and rancho shocks .I bought them off this forum from 9 sec comet sight un seen .With a new set of slicks a change to 4.10 gears and my cal tracs and a freshed up 460 .I am in the 10s .Just barely lol! 10.99 .I have consistent 1.52 60 fts .This is without any tuning so far .I didnt have to much convertor .Just not enough rear suspension !Trans still ok .My 8" convertor is like a sledge hammer at the line .I might change out my rpm airgap to a victor to see what will happen .Time will tell Doug