Ford C6 Governors

Hope you guys can bare with me and/or find this information helpful. I have 5 different C6 governors that I have disassembled, weighed each valve and found each valve's spring tension. All tension #'s are measured if spring is depressed into each valve's bore to edge of valve. I can tell you do not judge a governor by it's governor body part number alone, the internals can have some surprises.

1st Governor: C6AP-7A300, not sure of vehicle application.

Note primary valve design and spring design/location differs from all other governors.
Primary Valve: 64.5g or 2.27oz  Spring tension: 11oz @ .150"
Secondary Valve: 17.1g or .60oz  Spring tension: 38oz @ .264"

2nd & 3rd Governor: RF D4AP-7A300-AA, '76 T-bird, have 2 of these exactly the same valves and roughly same spring tensions.

Primary Valve: 66.8g or 2.35oz  Spring tension: 9.8oz @ .325"
Secondary Valve: 16.6g or .58oz  Spring tension: 38oz @ .264"

4th Governor: D4AP-7A300-AA, '80 F150 W/ 302(note governor body number and internals compared to both other D4AP units)

Primary Valve: 66.6g or 2.34oz  Spring tension: 13oz @ .202"
Secondary valve: 14.1g or .49oz  Spring tension: 32oz @ .264" Note 1/4" check ball found inside, again like the other D4AP governors.
**Cavity in Secondary valve measured from edge of valve: .800" L X .219" diameter**

Here are pics showing differences in this valve compared to the other D4AP Secondary valves:
Top valve with rings is from '76 T-bird, lightened valve has no rings


Shows center cavity of both, T-bird top and '80F150 on bottom:


Shows differences in overall depth of cavity measured from edge of valve:

Top valve has a depth of .264",  bottom lightened valve has a depth of .800" X .219" dia


5th Governor: RF E4TP-7A300-AA, NON-DIESEL APPLICATION

Primary valve: 67.7g or 2.38oz  Spring tension: 9oz @ .466"
Secondary valve: 16.7g or .58oz  Spring tension: 35oz @ .265"
Extra secondary valve weight:1.7g or .05oz, as reference a 1/4" steel check ball weighs 1.0g or .03oz

I apologize for the long posting, but hope this info is somehow helpful to the members here.

Nice Work. Must take note of some I have . Be interesting to test different ones .

No wonder some shift a bit different

Greg,
The Hi-Po C4 valve body/governor information you so graciously sent me, had me wanting to investigate my C6 governors further in an attempt to tweak my C6's shift characteristics. The biggest surprise was the lightened secondary valve in a truck governor, it looks like they tried to "temper" the shift rpm(lower the WOT shift rpm) somewhat by installing the 1/4" check ball to effectively making the valve heavier by 1.0 gram. The "truck's" secondary valve is 16% lighter as compared to the other D4AP secondary valves I have on hand as well as a lighter tensioned sec. valve spring. In all these governors(other than the 2 T-bird units) there were very few consistencies, either in valve weight, spring tension or spring bore depth within the valves. I have previously heard there was just a "car" and a "truck" C6 governor(plus a Hi-Po CJ version) with not many variations, FWIW this little investigations proves differently. No wonder there is just so few articles regarding C6 governor modifications(possibly due to so many variables involved). It will be interesting to see how my WOT shift and mid-throttle shift characteristics are effected when I re-install my governor with the lighter secondary and primary valves(drilled/lightened to 62.5 grams) along with the lighter tension secondary spring.

Update: Changes made to governor and valve body shift spring tension have given great initial results, part to mid throttle shifts are not only at a higher rpm but also feel more positive/quicker. The installation of the 15-16% lighter secondary governor valve seems to have really helped the shift characteristics to get them where I wanted. I have yet to do a WOT run due to making sure no adverse affects from all that was done(slipping or other shift issues). Part throttle shifts are roughly 800 rpm higher, 1-2 shift happens @ 22mph and 2-3 shift is roughly @ 40 mph, still looking to tweak/tune modulator, may have went too far with Mod. rod pre-load. More testing needed to verify changes helped downshift at stop issue(too low mph), modulator pre-load changes may/should have an impact on this. Once more road miles accrued I should, hopefully, have a more detailed reply with positive reults.

Great feedback Todd. Those shift speeds would be about right . This will stretch the shifts out a touch more with more throttle . Well done.
I have found with modulator , more spring tension by adjusting the screw in they actually become more sensitive/ responsive as in drop down gears a little earlier

After adjusting modulator valve to 12lbs with .040" pre-load when installing into trans case, I went for a drive(it has been raining for weeks here in central Florida). Still no WOT feedback(sorry for that), 1-2 and 2-3 shifts are again at a higher rpm during part throttle operation, roughly shifting @ 22 and 42 mph(of course depending on just how much "part throttle" pedal pressure there is). The biggest plus is the 3-1 downshift while coming to a stop, it now occurs consistently between 12 or 13 mph, allows the drivability to be a bit more enjoyable.

I had experimented with just using a lighter spring without removing any material from the valve and that turned out to be a fail. It did raise the shift points, but way to high of an rpm for
my liking. I have no way of measuring spring tension so it was just a simple experiment. If your Ranchero is shifting at 22 and 42 mph I'm curious what rear gear you have in it and at
what rpm it shifts at.

Great information BTW.

Randy

rmk57 wrote:I had experimented with just using a lighter spring without removing any material from the valve and that turned out to be a fail. It did raise the shift points, but way to high of an rpm for
my liking. I have no way of measuring spring tension so it was just a simple experiment.  If your Ranchero is shifting at 22 and 42 mph I'm curious what rear gear you have in it and at
what rpm it shifts at.

Great information BTW.

Randy

It has a 3.25 gear with 27.5" tires. I have it shifting near 3k at light pedal pressure just to see when it will shift, it results in the 22 and 42 mph numbers. Once I do a WOT run I may find the rpm's too high for my liking . I do know the downshift from 3 to1 at a stop or light traffic seems just about perfect with no harshness like I previously had when I had a 1/4" check ball located within the secondary valve's pocket. I used a jewelers scale to measure valve weight and valve spring tension, weighed them 5 different times to be sure(or as sure as I could) the numbers published were as accurate as I could measure.

Hello, great topic. I picked up a C7AZ-7C063-A being sold as a '70 Torino 429 CJ/SCJ governor, but C7 prefix has me skeptical. Does anyone have a reference for this p/n at all?

I have a '67 C6 PGA B tag out of a Fairlane, 390-v2 column shift going into a 63.5 Galaxie 500XL 390-4v>410/445. I am having #5,7,8,9 rollerized with a Broader Performance rebuild kit. I think I will do their truck calibration or stage-4 shift kit, if anyone has any experience, but I figured it would also be a good idea to try to delay WOT shifts a little via the governor while I'm in there.

It sounds like there's no telling which secondary valve I would have in either my stock gov. or w/e it is I just purchased. I suppose I can weigh and measure each or just run whichever has a deeper pocket, but would it be fair to say that if I find a secondary weight or a ball bearing in there, to remove it and move on with life? Is there also a spring that I should source? With all the work required to get to the gov., I want to try to avoid as much trial and error as possible. Thanks!

The one I used was a DOOZ part number and had a white paint mark , not yellow like the one that was in it originally.

C7AZ-7C063-A was just 3/8" deep with the check ball removed. Assuming I won't find a performance secondary valve piston, should I just remove the check ball from my stock unit from 1967 if it exists, or leave it as-is?

I am no transmission technician, but I found removing the check ball from the secondary valve, seemed to do more to change the downshift characteristics of my C6. I realize it takes a bit of elbow grease to "adjust" governor, but that will be the only way to tailor your shift points(well maybe not the ONLY way, but I found it is the correct way). I myself wouldn't "lighten" the secondary valve until I tried it as is with the check ball removed. Hope this is helpful

Thanks! ...so not a bad idea to just start with eliminating the check ball, or leave it as-is then remove check ball if need be?

This whole checkball thing is very interesting. I have never come across a governor with the ball in it

Gregaust wrote:This whole checkball thing is very interesting. I have never come across a governor with the ball in it

Hey Greg, I know we have conversed on the secondary valve's checkball before, I have seen a couple just not sure if they were a "rebuilders idea" or a well known "trick" by the rebuilder community to help with "something". I did notice a non-rebuilt C6 the governor had a small machined weight installed, you can see it above in pics I previously posted. I never knew my long tail shaft C6 I have in my current Ranchero had the checkball until I tried to tweak my governor's operation/shift points, once I installed the Transpak shift kit is when I noticed an earlier forceful downshift which caused me to investigate. When my C6 was basically stock or with the basic B & M shift improver kit I had installed years ago after it was rebuilt for the first time, it never had the downshift issue while coming to a stop. I am guessing the increased line pressures that the Transpak kit provides, along with the checkball were causing the situation, but again, I am no transmission technician

Part of the trouble of going off of casting numbers is the same aluminum casting can have different internals as you have seen. The earliest "CJ" governor was developed for the 428 Police cars and Shelby GT 500 and is why another poster found one with the C7AZ part number. That same governor was used in the Cobra Jets through '70. The DOOZ version was recalibrated for the 429 CJ Mustang and Torinos and did replace the C7AZ version When new , these had a white paint ID mark instead of the normal yellow paint mark of the standard governors.
Randy