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C-6 Transmission I.D. and rebuild questions.(maybe sticky?)

167K views 208 replies 45 participants last post by  Jetman 
#1 · (Edited)
this top post will get added to as the more info i come across, with internal mods, part numbers and so on. Enjoy.

long tail , short tail...

where too look up years and what not?

I wanna lay down some base idea's on this transmission and its parts and what we have done too make them work!

I have two different C-6 tranmissions sitting here. One seem to have a longer extension housing, and the odd side mount setup.

Ill post some pics of both tranmission's

transmissions


tails


tail one


tail 2


i just too make sure i can swap internal's and output shaft's and housings

heres a good readup on rollerizing a C-6
http://www.460ford.com/forum/showthread.php?t=105057

and a build up on a Big C-6 with trans brake or manual valve body. (fixxed)
http://www.460ford.com/forum/showthread.php?t=105603

5 clutch drum setup with pics and info (thanks greg)
http://www.460ford.com/forum/showthread.php?t=121505&highlight=clutch+drum+setup

TCI trans brake fix pre frank!
If it's a TCI I have a fix for it as the problem is the 2 checkball slots in the lower half of the valvebody are too large and too long and the checkball cannot find there seats in the spacer plate. there should be 2- 1/4" steel checkball ,one in each slot . you need to fill these slots with JB WEld or another good 2 part epoxy , then using the spacer plate as a pattern mark the 4 checkball seats in the epoxy - using a 9/32" drill bit drill 4 holes in the epoxy approximately 9/32" deep at the 4 marked spots, then using the drillbit router a new checkball slot in the epoxy , make sure the checkballs will roll free from one end to the other in both slots - install the spacerplate and check to make sure the checkballs will roll from one end of the slot to the other and not over shoot there intended seat, the holes in the spacerplate should be 7/32" for the High checkball and 5/32" for the low checkball . In between the lower half of the valvebody and the spacerplate there should be a gasket ,if there is not make one out of .005" gasket material, Torque all Valvebody bolts to 55 inch/lb's
Frank
manual and trans brake for tci info!
Okay now , Who Manual as if it's a Tci for the Manual you need to modify the 2nd gear servo and plug the servo vent and for the TCI brake VB your have to run the servo unmodified and the vent hole open


im putting this here, just incase someone dont click the link and all the info is in one thread!
C6 trans build for transbrake or manual valvebody
This is what I do aC-6 build and it seems to give good durability

- Low /reverse Clutch
- piston use the old style with the 24 return springs and the check ball , locate check ball at 12 o'clock (these springs have a free length of 1.070" as opposed to the high/reverse free length of 1.400"
- fibre's & steels , I prefer red alto's and kolenes but the stock clutches hold up well, If your trans has a waveplate discard it . I like to have a min of 5 fibres and steels set at .060 clearance ( .012 per fibre and steel) . the pressure plate may need a step machined in the out edge twice as thick as the snapring to aid in installation of the snapring, use a magnet base dail indicator mounted to the rear sprag race to check clearance- air check
- rear planetary hub use the one with the 1" long splines Part# for the hub F81Z-7D164-AA
- rear planetary- preferred is a 4 pinion
- Forward clutch - prefer red alto's and kolenes,and use the new style drum (new style has a wave plate, 5 & 5 here plus the wave plate .040-.050 clearance, the pressure may need a step machined in it for the snapring or you can use a second internal pressure plate as the outer , make sure you have the right forward ringgear assemble . the new style drum has a .400 deep torrington pocket were as the old style only had a .330 deep pocket and the ringgear asembles are different the new style has longer splines on the outside and the hub is different also. a missmatch of parts here will raise havoc with end play , the planetary's are the same 3 pinion, the reason for using the wave in the forward is that with racing line pressures and no waveplate it tends to snap the end of the drum off at the snapring groove after a period of time .In my max effort trannies I leave out the wave and contend with the drum breaking if and when it happens , ussally I just put an new drum in each year

2nd gear - "R" servo and an "E" lever and the toughest spring I have , Band I been getting good service out of the 2 1/2 " flex band kevlar lined

- High/reverse drum , 5 clutch drum preferred, but the stock 3 clutch drum can give good service if modified by cutting a new snap ring groove . there is 2 alternatives here depending on which drum you have as some drums have a longer spline than others the ones with the long spline an new 1/8" groove is to be machined in the drum at .565 from the bottom of the original to the top of the new groove this will allow you to use one of the stock selective snap rings to achieve a clearance of of .012 - .013 per fibre & steel and using alto pt# 026757HP kit you can install 6 fibre's and 6 steels witha clearance of .072-.078 (note Alto's recommended clearance with this kit is way to tight) with the shorter splined drum you machine a new snap ring 11/8" groove in at .400 up from 5the bottom of the original groove to the top of the new groove and then step cut the pressure plate approx .165 " to allow snap ring installation and removal. With this mod the drum will hold 5 x 5 standard red alto's and kolene steels . another drum mod to do is drill a series of 1/8" holes into the perimeter of the drum in a zig-zag pattern were the steels engage in the drum , this ads in letting the oil out of the drum a cools the clutches by letting more oil flow through between the clutches , also fill all spring pockets in the piston with springs.
-pump sealing rings , get and use teflon sealing rings as they last a lot longer than the cast rings and they do not wear the drum
- set trans end play at .020-.045"
- and adjust the band , tighten to 120 inlbs and back of 1 1/2 turns and tighten lock nut


any Questions email me at fmerkl@eidnet.org or call 403-793-5412




so how do we id them? so i can clean them off and check?

are there any case mods? I plan on doing this over winter. so i can be ready come next year! i do have a c-4 sitting here and the input adapter. but its seems it take a lot more money to build the c-4 too take the abuse i wanna put thru it. and the internals seem to be smaller and light, but just dont look as strong!IMO.

reading will best serve you here. clicking the links and reading this thread can help on tons of stuff.
 
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#57 ·
newbie questiom-found the thread very informative

ok so i just bought 1970 long wheel-base ranger w a DIVE 460 w c-6, not sure what from im thinking a later 70s truck. ok so i have two questions.

one, ive never really used a ratchet shifter before (this truck has a b&m mega shifter) and im unsure of exactly how it works? and it seems to be somewhat difficult to shift from p to n to r to d. just takes more force than i think it should. and whats the deal w the reverse lockout?.

two, what can i do to this tranny and or rear set to increase the max speed per gear thus increasing the overall top speed of the truck...to say the 140 -160mph+ area
 
#58 ·
same shifter i have in my car.! only the car model. the cable could be pinched or melted causing it to be stiff! but i slam mine all the time. when i pull it back to 1 and it rachets from there. pulling up on the t handle should help with the reverse lockout and shifting to park and whatnot! just sit in it one night and play with it till you get it down pat! thats what i did.

only way to incease top speed would be to put taller tires on. lower # rear gears or a gear vendors over drive unit on the back of the trans.
 
#60 ·
wesperkins said:
What is the length of the short tail housing? I just got a c6 out of a f150 ranger and am unsure of which tail housing it has. Does the long one have the side mount and the short one doesn't?

Thanks,
Wes
yes that is it. long has the funny mount. and the short one has a normal mount. hope this helps
 
#61 ·
Yes that certainly does. I thought that was the case but just wanted to make sure that was what i had, and it is. Just another question... and i am sure that i know the answer is yes, but will C6 will be plenty strong enough in my fox mustang without changing anything? I only plan on doing a full manual valve body and 35-3800 stall converter. I already have examined the fluid and the contents of the pan and everything looks good. It already has a hardened input shaft and we reckon that it was rebuilt not long ago because the input shaft looks perfect and there isn't any sign of bearing wear, plus the original torque converter looked fresh. front and rear seals also are good with no deterioration to speak of. this is going behind a mild engine build (street/strip being about 98% strip)

.030 over D1 block
15cc dcup KB hypers
new CJ/Truck rods
stock crank
Lunati 61605 cam (241/249@.050 dur., .582/.600 lift, 110sep/106 center)
Miller 1.8 roller rockers
home ported D0VE heads with 2.19/1.76 valves and comp 930-16 dual springs
probably stealth intake and 850dp Holley

Is there anything you guys would recommend that i should do? Right now i am waiting to build back up funds for the Block and Head machine work and am trying to figure if i need to do anything to the tranny while i am at it. The rear (for now) is going to be a bone stock 8.8 with Limited slip and 3.73 gear set, and girdle.
 
#62 ·
as you my have read, frank has went 8.00 on a stock input shaft. and it would be penlty strong in stock form for what your tryying to do.depending on how many clutchs are in each pack. but make sure you put a nice big cooler on it that can get penlty of air across it.overheating is the number one cause of trans failure. and stall converters just build more heat.
 
#63 ·
Hi, just took my new front engine dragster out for its first outing and i have a bit of a problem with 1st gear and 3rd gear, im hoping you can help. Its a (supposedly) rebuilt C6 with a reverse manual valve body and a transbrake (transbrake isnt connected at all yet), The Convertor is a 4600 stall, and the motor is a 528 stroker with Edelbrock RPM CJ heads, a holley 950 and a pretty mild solid flat cam (245/255, 590/615, 110 Lsa if i remember correct). Rear axle ratio is 3.89 and the rear slicks are 31" tall.

1st gear:

ok from standing i have to put on a fair few revs before the car wants to move in first gear - feels like the brake's are on when it is moving too... If i shift into 2nd gear the car moves nicely with virtually no revs. Over the weekend the car ground to a holt in first and i couldnt get it to move, so i shifted to 2nd and ran it in 2nd. We adjusted the brake band and it seemed better but not correct... we dont really know much about this sort of thing.

3rd gear: With the car up on stands i can go through 1st, 2nd and 3rd no problem.... but when im going down the track i cant seem to shift to 3rd. I make the shift but not a lot seems to happen... in eliminations i stuck with it in 2nd, running a 12.68 @ 109.67mph. I kept the RPMs real high (and since have been pee'd off with myself about it as i cant afford to blow it up!).

Any help / advice would be appreciated
 
#65 ·
Yeah, im 99% sure it is a TCI transbrake... as with most of my stuff i managed to get it used and it was a "bargain" for me in the uk, as bringing stuff over (even with the great exchange rate) is expensive. Seems like you have heard these symptoms before... any advice would be gratefully recieved... i have another valve body that we could maybe drop in but ideally id like to keep the transbrake
 
#66 ·
If it's a TCI I have a fix for it as the problem is the 2 checkball slots in the lower half of the valvebody are too large and too long and the checkball cannot find there seats in the spacer plate. there should be 2- 1/4" steel checkball ,one in each slot . you need to fill these slots with JB WEld or another good 2 part epoxy , then using the spacer plate as a pattern mark the 4 checkball seats in the epoxy - using a 9/32" drill bit drill 4 holes in the epoxy approximately 9/32" deep at the 4 marked spots, then using the drillbit router a new checkball slot in the epoxy , make sure the checkballs will roll free from one end to the other in both slots - install the spacerplate and check to make sure the checkballs will roll from one end of the slot to the other and not over shoot there intended seat, the holes in the spacerplate should be 7/32" for the High checkball and 5/32" for the low checkball . In between the lower half of the valvebody and the spacerplate there should be a gasket ,if there is not make one out of .005" gasket material, Torque all Valvebody bolts to 55 inch/lb's
Frank
 
#69 ·
thanks frank

heres some pics



ill be doing a step by step build on this trans for everyone to see with franks mods and whatnot. color pics and all. i just need to get a few more parts and due to moneys issue, lord knows how long that will take. for now ill be doing it none roller other then the #9 thrust washer will have the roller bearing.
 
#73 ·
Teflon sealing rings

I have a question on the teflon sealing rings. We switched from the cast iron rings to the teflon. We coated the teflon sealing rings with assembly grease to install. We tried filling the port with trans fluid several times and air checking with no luck. So we pulled it back apart and checked to make sure we didn't pinch a seal putting it together and everything looks fine. We air checked the drum while it was out and it checked out fine. So we put it back together and tried air checking with the fluid first with the same results. We talked it over and thought it was just the grease holding the seals and once the trans was up to temp it would wash the grease out and seal up fine, so we put the car back together. We tried it the first time last night and everything works except high gear. We ran it long enough to get the pan warm enough that you cant leave your hand lay on it and still no high gear. Any ideas?

Thanks in advance

Mark
 
#75 ·
Frank

Thanks for the speedy reply. Yes we do have reverse. The FWD drum is the one that wouldn't air test. I think the problem is in the governor. We just freshened a race only trans that had the governor removed, the support turned down and the distributor sleeve machined off down to the pin for the park lever. It had a TCI transbrake valve body. We are running a transgo stage 3/full manual forward shift valve body. The separator plate in the TCI V\B had the governor holes covered (if my memory is correct). Ours used a modified stock separator plate. We are planning to go to the brake V/B in the future so we went with the teflon seals, rollerized it, and lightened up the governor parts. Do you sell a kit to convert a valve body over to the transbrake that we can install? Sounds like TCI has some problems with theirs. We are going to pull the tail housing and distributer sleeve and plug the passages in the sleeve tonight and see if that fixes our problems for now.

Thanks again

Mark

That mustang of your's is awesome, are you running a power adder to go 8.00's?
 
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