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1966 C6 Build & Rollerization, Part 2-Modification

24K views 21 replies 8 participants last post by  gregaust 
#1 · (Edited)
Hello,

This is part two, modification of the C6. Please see "1966 C6 Build & Rollerization, Part 1-Tear Down" for disassembly.

I'd like to talk about what I did and most importantly why I did it. Anytime you modify anything you need to have a clear goal in mind otherwise you could end up wasting time and money on one aspect and not enough on the part(s) that need it.

The application is a 1966 LTD, 4 dr hdtp with a 390 (currently being built) estimated in the range of 450-500 hp @~5400 RPM. Nothing else has changed on the car, the weight is ~3700 lbs. with a 3:0 rear end and factory size tyres. Since the transmission is from the car, the factory calibration of shift points and line pressures should be satisfactory but we can fine tune them on the shakedown drives.

I feel it is important to touch on "shift kits". I've had my fair share of them. While it appears "shift kits" are under the guise of a "must have", a overly harsh shift is just as damaging as a extra soft slipping shift. For my application, there will be no shift kit.

Let me explain why, first this is a nice cruising car with a beautiful interior, the exhaust will be quiet but allow the necessary flow. I don't want to feel the shifts under normal driving conditions. Now it's true a soft shift will wear away the frictions more quickly than a firm shift. But you should replace trans fluid every 30K miles anyway, and so what, maybe the frictions will only last 200K miles versus 250K. This is Fords top of the line LTD not a gutted out race track warrior. But the choice is yours. I already have a car with a firm shift kit, and I can say it is not obnoxious but it does get old to the point I do not wish to drive it every day. But that's just me. OK, I've said my peace :) on this.

The modifications needed to live behind the higher power of the 390 will be adding an extra set of friction and steels in the forward and direct clutch, a wider band, and we're going to use Red Eagle frictions with Kolene steels.

What I elected to do also is "rollerize" the transmission to reduce energy wasted internally. You can look at this as wasted power not reaching the rear wheels under full throttle conditions or conversely under normal driving conditions wasted fuel turned into heat and lower MPG.

The following are two books that were paramount for tackling this as well as some web resources I'll also post.



The shop manual is the absolute must, the "How to Rebuild and Modify Ford C4 and C6" book is really an addendum or supplement if you will to the shop manual. The reason I say this is while I've never opened a Ford C6 before but have several GM transmission rebuilds successful under my belt, the book was a little confusing to me. I had to read it several times and unfortunately by the time you get to the C6 section the author assumes you are intimately familiar with the C4 and makes many mentions comparing the C6 to the C4 upon disassembly and modifications. I found it kind of confusing trying to learn just about the C6 while not having empirical knowledge of a C4. As a result I found myself constantly flipping around the book.

But I did learn a few tips and tricks from the book, which is why I consider it a valuable supplement. I think it's nearly a forgone conclusion that the big C6, while very robust is also an energy vampire.

Here's a snippet I found on the 460 forums concerning this.



The link to this is Roughly how much power will a C6 rob? [Archive] - 460 Ford Forum if you wish to research it further.

While I could not find any direct evidence of power savings by rollerizing as it were I did come across a singular post stating after rollerization his particular C6, it absorbed only 30 hp.

As with anything not backed up with evidence take it with a grain of salt. I figured it couldn't hurt only help. The process of rollerizing is replacing key flat thrust washers with Torrington bearings. This requires machining of the rotating parts as the Torrington bearings are thicker than the stock flat thrust washers.

While I took my lead from the book on rollerizing the C6, as with anything you can just buy everything already machined as a kit, but it is $$$. Eventually I plan to change out this C6 for a built up 4R70W trans for the overdrive and lock up ability so I do not wish to invest several hundred to a couple thousand into this. This C6 was just a chance to stretch my skills some.

Since I have a little cheesy lathe and mill and the Torringtons are inexpensive I elected to do the machining myself. I then found this posting on the 460 forums:



This is the direct link to this: Rollerizing a C6 [Archive] - 460 Ford Forum

So a big shout out of thanks to Frank Merkl as this saved me some time researching part numbers on the Torringtons I would need.

I did take his modifications one step further with the addition of the rear thrust washer also replaced with a Torrington. He mentions it shouldn't be under load and therefor doesn't need replacing, but from the below picture it is quite worn (far left one).



You can see the new thrust washer and the Torrington in the middle meant to replace it. This is a Ford Torrington used in the E4OD, which if you're unfamiliar is a modern 4 speed overdrive trans based on the C6.

For the following pictures and remainder of this section I am concerned with tolerances and not with seals or unnecessary cleanliness or complete assembly. This is dry fitting the rotating internals and the machining on the parts. The next section/thread will deal with cleanliness and proper assembly techniques.

Enough of my boring banter, more pics....



The original thrust washer and it is worn. This transmission has approximately 100K miles on it.



The E4OD Torrington fits nicely in place.



Because the Torrington is thicker some material will have to come off the parking gear, but as I could not find a manufacturer thickness of the Torrington. Therefore I had to measure the height differential between the thrust and the roller bearing.



With the heavy tailshaft in place I carefully zero'd out the dial indicator, then slipped the Torrington or roller bearing in place and measured the height difference.



Then I chucked up the parking gear and removed the difference in height.



That one is done.



Next is the #9 thrust washer, this sits between the rear race and rear planetary ring gear/hub.



This is the Torrington to replace the thrust. Again the difference in height has to be removed from the race face. Ha race face, I'm a poet and I don't know it.... But seriously, they sell the race already machined with the Torringon. But heck I was on a roll with the lathe so I machined the face of this race down.



Fits nicely. As a side note the race looks to be inductioned hardened around the edge. I left it as it clears the bearing. A carbide bit will not cut this, to remove it, it would have to be ground down. But it is not necessary.



I temporarily assembled the tailshaft bits back together to check clearances with the new rollers. And wow, what a difference to spin even just this on rollers versus the flat thrusts.



Next up is the #8 thrust washer to be replaced with the roller bearing to the right.



For these bearings I followed Franks advice and cut the difference from both the back of the hub and the rear planetary.

To remove the back of the hub from the ring gear, remove the snap ring and lift up and twist.



like so



I machined that bit as he stated



Then the back of the reverse planetary



That one is done.



Next up is # 7 thrust washer to be replaced with a Torrington.



like so



Next up is the #5 thrust washer, this is between the forward planetary and forward clutch inner hub.



like so, the same machining pics as shown earlier apply to these parts.

That completes the rollerizing steps, next is regrooving the clutch drums to hold an addition set of friction and steels.



After carefully measuring the drum and determining the extra thickness of the new friction and steel, I then selected the middle size of the snap rings available to calculate my new ring groove. The reason I did this is because if I was off in either the + or - I can then use the thinner or thicker selectable snap ring to bring my overall clutch gap to tolerance.



I found to accurately measure the clutch gap or the pressure plate to snap ring gap is to exert pressure equally on two opposite sides and then take a reading with your feeler.



To turn a new groove in the clutch drums (forward and direct) I made a tool from a cheap of generic carbide set I bought at Harbor Freight.



It took a while to grind the profile on the bit but considering how much a proper ring grooving tool costs it was 15 minutes well spent.



To finish up the forward clutch I needed a newer ('68-up) forward planetary ring gear as the '66 to mid '67 has fewer teeth than its successors. The reason why this is necessary is Red Eagle frictions for the forward clutch ONLY come in the higher tooth count. But any transmission shop should be able to sell you a used ring gear.



Just install the newly machined hub onto the newer ring gear and replace the snap ring.



Test fit everything into place and make sure the teeth are all engaged. This takes care of the modifications to the forward clutch.



This is the old band, notice the width.



This is the Red Eagle width. Should have loads of extra holding power for the same pressure on the servo.



Next up is the direct clutch, the old frictions and steels versus the new ones.



Again, took measurements and regrooved the drum.



Again just like the forward drum double check the final clutch gap and adjust with the different thickness snap rings offered if needed.



Even though this picture is from the final assembly, I wanted to show what the final step in this should be. That is to check the total end play of the transmission and select the appropriate front thrust washer to bring that end play into tolerance.



So here after bolting the pump back, with the old gasket is fine. But all the frictions and steels are not in the clutches at this point and the transmission is standing up right to ensure no Torringtons or remaining flat thrust washers have dislodged. Taking this measurement is important because upon the real final assembly if this doesn't match your measurement then something is amiss and you can catch it before installation.

To check the total end play use the screwdriver to push up after pushing down on the input shaft and zeroing the dial gauge.

Right that concludes the modification portion, please see "1966 C6 Build & Rollerization, Part 3-Final Assembly"
 
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#2 ·
Excellent write up on the C6 build. It is pretty similar to the AOD and 4R70W on the inside. I guess it's a Ford thing.

I am very jealous of that lathe! You have your own machine shop in house!
 
#3 ·
Agh thanks fried_daddy for the kind words. The 3 in 1 mill-lathe-drill is nothing to boast about. It's a Smithy model I bought eons ago. I think all the extra fixtures and fittings I've bought along the way cost more than the Smithy originally did. I'd much rather have a Bridgeport and a proper gear driven machine lathe.

Cheers...
 
#4 · (Edited)
Yeah, not having the tools I purchased all these parts ready made to drop in.
To those following the thread, all of these parts can be bought from Jay at Broader Performance.

Desert, I think you should be using a shift kit just the same.
I run the TransGo SK6 in my truck, set at level two it is just a fuzz harsher than a stock valve body, but it ups the pressure for sure which as I'm sure you know helps in longevity. 55psi is cool, but with the engine you are looking at installing, a little more would be a little mo betta

The whole "how much HP does this trans consume" is retarded.... it's obviously a deal with folks that do not really understand how a transmission or an engine works. I mean, a transmission will require different hp at 1000rpms, 2500rpms, 7000 rpms, etc. Simply playing with line pressures will change what it takes to turn the trans. I remember Frank once mentioning he pressurized the drums and used a torque wrench to turn the trans. I forget what it was, but something like 40ft lbs non-roller, and 12ft lb full roller. A c6 isn't the most efficient racing transmission simply due to the rotating weight, and the fact that large parts need to stop/start at high speed. This can't really be measured in horsepower, this is best noticed as "engine recovery" and would be hard to see unless you are on a wheel dyno or the track. This measurement would be pretty useless to those of us with street cars.
 
#5 ·
Hi DeepRoots,

Thanks for the feedback. I know most folks probably do not have a lathe or feel like taking their parts to a machine shop. If I was planning on keeping the transmission in the car I probably would have bought the kit that comes with the rollers as well as change 1st and 2nd gear ratios to widen them a bit to help with acceleration.

But to do the roller conversion on this at home was only 40 dollars in parts, so what the heck :)

For me there's no reason to have a "shift kit", as long as the transmission is adjusted so that no slipping occurs at any time, especially under all load conditions. Granted some people like that firm feeling of shifts. I do not. To me it totally degrades the enjoyment a big cruising car.

I'm setting this C6 up similar to my even larger cruising car I did nearly 20 years ago and still going strong. It's a 1973 Chevrolet Caprice convertible fully loaded with the factory 454 option, Turbo 400, etc. It weighs in close to 5000 pounds :eek: with stock size diameter tyres and a 2.73 rear ratio. It's much heavier than these 60's galaxies and bigger too. I built up the engine and built up the transmission with no shift kit, just careful adjustments. As a result you do not feel any shifts under half throttle. Under detent conditions it firms up enough for quick shifts while not being a nuisance.

As a result, it's an absolute joy to drive. It's quiet, smooth, very roomy, and still packs one heck of a punch when you nail it. Every transmission oil/filter change the ATF is pink and a little gray matter at the bottom. Like I mentioned earlier if the frictions only last 200K miles versus 250K miles so what, to me it's worth the comfort factor, kind of like air conditioning robbing potential engine power or the extra weight of power windows and locks. I love all these creature features :)

I'm building the LTD to match these characteristics of the big Caprice. On the plus side the LTD is lighter ~3700 pounds verses ~5000 and with a 3:0 ratio axle. With a less powerful engine as the Caprice the C6 will see even less loading as the torque differential (input-output shaft) is lower than the TH400 and the C6 is comparable to the TH400 class wise. This will be a doddle for the C6.

But that's just me and I know I'm odd :). Besides I do not believe anyone makes a shift kit for the C6 with a dual range valve body (1966 only). The ones mentioned always say '67 on up.

Cheers..
 
#6 ·
Fantastic.
Yeah, I'd have liked to work with the local machine shop... but every time I explain something to them, they look at me like I grew an extra eyeball :)
Doesn't exactly inspire confidence....

On a slightly related note, my last two builds, I've been running this for fluid:

http://www.summitracing.com/parts/ati-100004/overview/

Just a fuzz more expensive than regular Type F, (really not that much). But I've been very impressed with how it runs. I have limited cooling ability with my 63, and it has really helped in that regard.

Drew
 
#8 ·
More great work I must say .

For me though and on the subject of shift kits , I won't put a stock valvebody back together . For me they are just too soft in the shifts . I've built a lot of C6 used in F trucks and find the SK-6 kit is just that nice little upgrade . Shifts are definitely not hard but just crisps them up that bit how I like .

Keep up the nice work , look forward to part 3 :)
 
#9 ·
Greg,
I agree with you and am a fan of the SK6. Can you use it on the early valve body (66 dual ranger that DesertXL has)?

I've run the second level on that for my daily driver truck and it's pretty smooth, third or fourth level for my car, which is a little more performance oriented.
 
#10 ·
I believe you can use in a 66 . They list in the instructions list the pressure reg part for 66-70. The mods made are the same as the later valvebodies at the servo regulator and 1-2 accumulator valves .
Pressure spring suits both early and late style regulator springs
I like the 3rd stage with the one large outer spring for the shortest 1-2 shift
 
#11 ·
Thanks for the great write up and pictures. This is the best yet and I've read many write ups on this. I'm rebuilding/rollerizing a C6 that is out of a 1971 Mercury Cyclone Spoiler, 429 CJ. I'm familiar with a C4, but I had never rebuilt a C6. I purchased all my rebuild parts/kits thru Broader Performance. He needs to copy your write up and send it with his kits. Yours, with photos, are much better. The kit I purchased is fully machined, so that is not an issue. So far, so good! Thanks again your documentary on the rollerized C6 trans! You should get paid for this.
 
#12 ·
VERY nice step by step instructions /photos.
I stumbled onto some "old stock" of Ford Motorsports rollerized C6 parts , both std and wide ratio , but not a ''complete" conversion for very little money. I spent right at $100 for the additional ( 4R70) parts to complete it. I also bought a Superior Servo ( R type) and shift kit, CJ governor , Kevlar (narrow) band Summit deep aluminum oil pan. In total the complete roller wide ratio trans build cost was under $500 bucks including a few "mistake" buys I ate.
I still have an NOS Motrosport boxed high drum , three four pinion standard ratio rear planetaries and one wide. All in Ford Motorsports boxes. $100 for all plus shipping from So Cal. PM if interested.
Randy
 
#14 · (Edited)
VERY nice step by step instructions /photos.

I still have an NOS Motrosport boxed high drum , three four pinion standard ratio rear planetaries and one wide. All in Ford Motorsports boxes. $100 for all plus shipping from So Cal. PM if interested.
Randy
That;s a bargain right there .. Does that drum have extra snap ring grooves of just the one for 5 clutches ..just curious
 
#15 ·
Greg, It has a single groove . I did hear Ford Motorsport was selling off 4 clutch drums at the end. I will check it and tell you how "far down" the groove is. I didn't use this one as my core was a CJ but came from the junk yard missing the R srevo. I used the standard width ( kevlar lined ) band so I didn't have to cut the 4R70W sun shell.
Randy
 
#16 ·
Greg, It has a single groove . I did hear Ford Motorsport was selling off 4 clutch drums at the end. I will check it and tell you how "far down" the groove is. I didn't use this one as my core was a CJ but came from the junk yard missing the R srevo. I used the standard width ( kevlar lined ) band so I didn't have to cut the 4R70W sun shell.
Randy
Just a minor point... but that would be the E4OD sun shell.

The 4R70W parts will not fit the C6.
 
#19 ·
Greg,
It is not "Motorsport specific" . "I" believe it is a left over production part "sold off" through Ford Motorsport. If you weren't SO darn far away $$$$ shipping wise , I'd send it to you. I'd like to see someone use this stuff. I only build for myself and extra parts I accumulate get sold off.
Randy
 
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