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C6 trans build for transbrake or manual valvebody

106K views 73 replies 33 participants last post by  gregaust 
#1 ·
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
- 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

Link to rollerizing a c6 http://460ford.com/viewtopic.php?t=8558&sid=393341777e7d9a6bd7958594ececc708
 
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#4 ·
Hi frank, when i was in the business"trans" we used the forward bottom apply plate for the top plate in the directs and machine down the apply plate in the directs.Using the laith carefully machine the top part of the direct piston,and setting in back in the drum, checking to make sure the tabs on the steel rides on the groves in the drum.this allowed,6 direct clutch& 6 koene steels.this was achieved in the stock 4 clutch drums.I also want to point out that the "A" servo arm is the highest ratio arm for the inter-band.This summer if you are up in edmonton give me a call,Maybe i will load up my car too.
 
#5 ·
Re: Fluild

Frank Merkl said:
Fluild : to be dead honest I've had good luck with castrol Type "F" and Synthetic dex III , syn runns about 10 -15 degrees cooler and doesn't get stinky as soon as type "F" , but then I abuse the hell out of my tran's

Frank
i run castrol type f also.i was curious if you were using the 5w20 mobil 1 synthetic i've heard of other people using.
 
#7 ·
Hp

Horse power through a C6 , No special parts needed
I put 1300-1400 hp through mine , I've got 4 - 10.0's- 11.50's cars running season after season , bullet proof ( one has over 500runs and ne wants to see how many you can get before it slows down and he run's 10.10's)
and a couple of big hp mud boggers ( 800- 1700hp) running a c6 and just bring them back in the winter for a freshen
Over 600 hp I recomend putting on an aluminum pan , at 800 ftlbs torque an aftermarket imputshaft . I ran a stock imput shaft to 8.00's
Frank
 
#8 ·
C6 2nd gear apply levers Ratio's
A- 1.65 to 1
B- 1.73 to 1
D- 1.97 to 1
E- 1.85 to 1
H- 2.18 to 1
F- 2.30 to 1

and this was copyed Direct from my FoMoCo Training school manual that I got in 1973
Frank

If you want to know why I like an "R" servo with an "E" lever , It's all a matter of shift timing , If you have the wrong lever with the wrong servo and the wrong servo return spring you'll end up with a bunch of burnt clutches flares or locks on shifts
Frank
 
#9 ·
Thanks frank for the info.I was allways under the assumption that the" a" servo lever was the highest ratio.Cause when you look at the lever,the contact area where the piston sets on and where the strut meets up to the lever they are very close together.When you go to a higher ratio rocker arm on a motor the push rod moves farther from the fulcrum.Under this understanding from motor rockers this would explain my misunderstanding.Does this mean that the "a" ratio arm would react quicker, but not hold better?I installed a "A" lever on my c6 with a "p" servo and spring assembly.
 
#10 ·
levers

yes an "A" reacts faster but give less applyed pressure , and applying too fast causes a locks on shifts (shift overlap) and also the wrong servo with the wrong lever for a give line pressure will cause a flare on shifts , there is so many combinations it would drive a person nut to try to figure them all out . so I stick with a "R"servo an "E" lever in my valvebodies because it took days on the dyno to get the shift overlap right ,IE just enough that the is no flare on the shifts and not so much take there is a tug on the shifts
Frank
 
#11 ·
apply lever

Frank, I am using a Coan billet high ratio (they don't give a number) apply lever with a "R" servo and I feel a tug when I'm driving in the pits and shift into second. From your description it sounds like the problem is the apply ratio is too high, based on the tug felt, and I should swap the apply lever to a lower ratio.
 
#12 ·
Rebuild?

OK. Since I know enough about transmissions to know to keep my big hands out of them, what does it normally run to get one rebuilt? Anyone here willing to do it for a fair price? I am wanting to run a single turbo 460 in an 89 Mustang with a C6. I would like to obtain 600 RWHP and pull the 1/8th in 6 or less seconds. It will be 99% 1/8th drag strip run with an occasional trip through town to scare them Shoveatoilet boys about half outta their pants.
 
#13 ·
Tug

VR3 , who's valvebody are you running ? it could be as simple as a hole in the spacerplate .030 to big , Alot of people building valvebody's don't have a clue about hydraulic's , you could send the valvebody up to me and I could Dyno it in a trans and see what the problem is .
Frank
email me at fmerkl@eidnet.org or call me at 403-793-5412
 
#69 ·
VR3 , who's valvebody are you running ? it could be as simple as a hole in the spacerplate .030 to big , Alot of people building valvebody's don't have a clue about hydraulic's , you could send the valvebody up to me and I could Dyno it in a trans and see what the problem is .
Frank
email me at fmerkl@eidnet.org or call me at 403-793-5412
Frank,
I have a 91 F250 300cid c6 that wont go into reverse. 1st and 2nd gear shift fine, to get 3rd, I have to allow the trans. to warm up and shift into Neutral then drop into 3rd. It goes into 3rd with no slippage and will run all day. I disassembled the valve body and noticed the gasket was brittle and a few small pieces missing( like someone had tried to reuse the gasket, also fluid looked good) could this cause the line pressure to be to low to engage the high/reverse clutch, or do you think something else is the problem? The valve body and all the valves and springs look new with no noticable wear. I am new to automatics and any help would be greatly appreciated. Read your posts and can tell you are the man to talk to!
Thanks,
Matt
 
#21 ·
Frank got a another ? for you can i take out the downshift rod out of the shifter rod and fill it with rvt i'm asking because i cut off the threds to the downshift shaft so i cant put back in the o ring and nut.I'm going to look at my c-4 in my cobra two i think thats how performance automatic does it.
 
#24 ·
What i did lastnite before i read your post is i moved the downshift lever all the way to the inside untill it hit the drum and cleaned the rod and inside the shifter shaft with brakeclean and put rvt on the rod and inside the shift shaft and then slid the rod back into the shaft and let it dry over nite my ? is does that rod need to move around in there ? i didnt think so because you have the nut and o ring on there usally i just want to make sure its not going to screw up the trans tomorrow, if it leaks a little no big deal i'll fix it right this week with a cup plug like you said is this a ok temp fix?
 
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