C6 Downshifting issues
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C6 Downshifting issues
Hey guys new to the page!
So I am having issues with my 1979 ford f150 downshifting from 3rd to 2nd when I lift my foo off the throttle to apply the brakes. this is a heavy slam into a lower gear at higher rates of speed and does not feel or sound good. Everything I have read online says vacuum modulator for correcting upshift problems but nothing about my issues. Is this still a modulator issue? The previous owner replaced the modulator and I have no idea what it is.
So I am having issues with my 1979 ford f150 downshifting from 3rd to 2nd when I lift my foo off the throttle to apply the brakes. this is a heavy slam into a lower gear at higher rates of speed and does not feel or sound good. Everything I have read online says vacuum modulator for correcting upshift problems but nothing about my issues. Is this still a modulator issue? The previous owner replaced the modulator and I have no idea what it is.
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I think it shifts just fine. it revs out if I get on it and shifts at a good spot when driving normally. I have not messed with the kick down linkage or anything else. The previous owner had the carb tuned by a shop I think but that's all I know.
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I checked the fluid the other day it looked low. Thought maybe that was why it was doing this. Went and bought fluid and now I can't tell if it high or low. one side of the dipstick looks like its high and the other looks like its where it should be... I don't know what else to do. Does anyone know anything to help?
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I checked the trans fluid and it was looking low. Now it was on more level ground and it looks high. I can not tell if the trans is over full. Is it possible this issue could be caused by being over filled? and or using the wrong fluid? I have heard you need to use type F in the c6's. my next step I'm thinking of trying is dropping the pan and replacing the filter since the pan is leaking anyway. I have not been able to find anyone that is having the same issues online so im running out of ideas. any help is greatly appreciated!
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Ford Parts Specialist
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From: Simi Valley, CA
I checked the trans fluid and it was looking low. Now it was on more level ground and it looks high. I can not tell if the trans is over full.
Is it possible this issue could be caused by being over filled? and or using the wrong fluid?
I have heard you need to use Type F in the C6's.
Is it possible this issue could be caused by being over filled? and or using the wrong fluid?
I have heard you need to use Type F in the C6's.
Including the torque converter, the C6 takes (edit) 13 quarts of ATF
1979 F150, what size is the engine? If it's a 300 I-6 or 302, it could also have a C4.
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Fleet Mechanic
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Dunno bout that 17 quarts ND, my 4x4 deep pan per the 76' Ford shop manual is 13 3/4 quarts, most other C6 applications listed in the same book are around 12 quarts if I remember correctly...Only reason its fresh in my mind, I just filled mine over the weekend for its first rebuilt journey..
Ford Parts Specialist
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From: Simi Valley, CA
Dunno bout that 17 quarts ND, my 4x4 deep pan per the 76' Ford shop manual is 13 3/4 quarts, most other C6 applications listed in the same book are around 12 quarts if I remember correctly...Only reason its fresh in my mind, I just filled mine over the weekend for its first rebuilt journey..
Edited the post...
More Turbo
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OP, is you transmission hooked up to manifold vacuum or is it, for whatever reason, hooked up to the ported vacuum off your carb? I read on a forum (this one or FSB) that a user had done that as an experiment and experienced what you are.
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So it looks like the trans vacuum line is running to a t fitting that splits to the heated vacuum thingy (not sure what that is. I am new to this carb thing.) and then it also goes to the fitting that goes in to intake cover. It has a purple modulator and the line is connected to it. it looks like it is not hooked to the carb at all. I am pretty confident its the c6 due it having the notched square pan and a solid bell housing. Im curious if the previous owner replaced the modulator and put the wrong trans fluid in it? Its always fun trying to un-***** someones mess.