Tranny goes bad because of missing kickdown tube?

[1968flareside]

That's the explanation I was given today as to why my trans is crapping the bed, supposedly. I maybe put 20-30 miles on it without the kickdown on it.

It still shifts through the gears before I reach 30 mph and it still slips going into 3rd. I cannot even feel it shift into 2nd. If I manually shift it into 3rd at about 40 mph, there is no slipping.

I did check the modulator. There was no fluid when I pulled the line off. Could it still be bad from just sitting? I know it hasn't been replaced in the near 10 years of sitting it has done. I was also looking at this guide I picked up a few years ago from the dark side I think. See below..

C3
Rectangular pan w/13-15 bolts.Can also have a slight buldge on front pass. side. Used on 4 cyl & V6s only. Strictly light duty applications. Not an overdrive tranny. Makes a good boat anchor. Shift pattern = P-R-N-D-2-1

C4
Built from 1964 - 1981? 17.18" long overall. C4 bell housing is removeable, C6 is not. Rectangular, almost square pan ( 10" X 9") with slight buldge on front pass. corner. Pan has 11 bolts. 5.0L engines tended to have C4s not C6s. Not an overdrive tranny. Fairly robust unit. Can take a fair amount of power. Eats about 60 less HP than a C6.

C5
Built from 1982 - 1986 Case length same as C4 but pan has a hump in it whereas the C4 has a flat pan. Not an overdrive tranny. Not even that widely used. Avoid.

C6
Built from 1966 - 1979 20" long overall including integral bellhousing. 1966 - 75 have rectangular pan with 17 bolts & long measurement on front and rear edges. Shorter on sides. Can have recess on rear pass.corner or slight buldge on pass side near rear edge & 15 bolts. P1966-75 pan = 1"-1.5" deep. 1975+ pan = 1.75" - 2.0" deep and 4X4 pan 3" deep in center. Small blocks and big blocks have different bellhousings. 3 different castings total. P-R-N-D-1-2 pattern. Good, heavy Duty 3 speed Auto, but without OD. Gets 3 thumbs up.

I'm pretty sure the author that shared this had a disclaimer of "not knowing every detail," or something. It says the bell housing on the C4 is removable??? My case is one piece. But, it does have the 11 bolts for the pan. I'm just anxious to figure this out.

I think I'll take to the local Aamco for a free eval. Anyone have any dealings, good or bad with Aamco?

[xxxtina63]

Have heard the same thing about the C4 w/removable bellhousing but have never seen one. Supposedly there were some C6's w/removable bellhousings but had iron cases. Maybe none is true but I have ran my C6 w/out kickdown for many miles w/no problems. Also, there wasn't any fluid leakage when I removed the modulator

[steveheer]

I've done some reading on the C6 power thing and I will say that there is no way that a C6 eats 60 horsepower MORE than a C4. Anyway, on most FORD transmissions the kickdown only causes a line pressure spike at full throttle--unlike Mopar transmissions which require the kickdown for throttle position all the way through since they have no vacuum modulator. I can't see how you would have hurt anything--it's just for passing gear. If it is slipping it was probably slipping before.

IMO

[MIX BREED 72]

I thought cast iron cases was the FMX and all the C4S had removable bellhousings. I also thought the C5 was basicly a C4 with a bigger flywheel and converter, this might be why I am not a tranny guy maybe someone here can let us know.

[1968flareside]

Do I need to drain the fluid to remove the modulator? I sure would like to replace it and the vacuum line to see if that remedies the slippage. It never slipped last time I had it running. Again, it has been sitting almost three years since I drove it last. I was shifting just fine then.

[fordman]

no you don't have to drain it. atleast i didn't have to when i did mine.

[1968flareside]

Ok, good to know, thanks!!!

[1968flareside]

I was also looking at this guide I picked up a few years ago from the dark side I think.

Yep, I was right. They're listing it as a tech article now! http://www.ford-trucks.com/article/idx/ ... Guide.html

[cdeal28078]

Too the best of my knowledge, meager as it is, all c4's and c5's had a removable bell housing. There were also large bells and small bells for easch tranny.
If it has a removable bellhousing and is behind an FE engine it's not a c4 but probably an MX or Fmx tranny.
These guys here are very good at any Ford tranny and can help with any problems you may have
clint
http://www.network54.com/Forum/260730/

[1968flareside]

Thanks everyone. I'm going to attempt to change the mod today, one handed!!!

[cdeal28078]

Have a catch can ready as some fluid might come out. It should'nt be more than a quart if it does.
Make sure to try and buy a mod. valve that is adjustable and make sure the pin behind the valve does'nt get lost as is put back in correctly
clint

[1968flareside]

Now you tell me... I just pulled it out and that quart you were talking about did come out. Oh well... Is this pin you are referring to on the mod. or inside the tranny?

My next question...

What do the band colors mean? Are they different so they will only fit certain applications? Just doing some searching on Napa, Autozone, and Checker sites show three different color stripes for the C4. I know I'll have to clean mine up to find the color, hopefully.

[1968flareside]

Well, I matched it to the green band modulator. I have installed it and added some of the Lucas Tranny Treatment. It is noticeable better. It does seem to shift too quick still and the slipping is still there, just not as bad. I did notice that the screw on the old mod was almost all the way out. The new one is pretty much all the way in. If I run the screw out, what kind of change should I expect?

Also, would a band adjustment make a difference? I have only read briefly about it. I have no clue on the how to part. Can someone break it down dummy style for me?

Thanks!

[fordman]

i know from adjusting the bands on a buick dynaflow from what i remember reading is loosen the lock nut and turn the screw in untill it gets tight back it out 1.5 turns and tighten the lock nut. but that is what i read for a buick tranny from the earlier 60's. ford would be about the same but i don't know if you go tight and then back it off or what but that is the general idea. jake gave instructions as to adjusting modulators a thread or two down the main page.

[bleedfordblue]

to adjust 2nd gear band, hold the stud still while backing off the jam nut, then tighten the stud to 120 in. lbs. and then back it off 1 3/4 turns. Now tighten the jam nut without letting the stud turn. By the way the stud I am talking about is on the driver side closest to the bellhousing. The only time this should have to be adjusted is if the trans is slipping going into 2nd from 1st or 3rd. Adjust the modulator by backing the screw off 1/2 turn at a time, no more. This will cause the trans to shift later. Do not go overboard, or you could cause internal damage.
Good luck,
Scott