Tranny HELP
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Tranny HELP
First my column shifter in my C6 will not go to 1 st.???
A C6 is a 3 speed ???
Or 2 W/OD ???
Seams like my RPMs are high at 55 mph.
Any ideas???
72 F100 AT column
Says C6 tranny but might be a C4?
A C6 is a 3 speed ???
Or 2 W/OD ???
Seams like my RPMs are high at 55 mph.
Any ideas???
72 F100 AT column
Says C6 tranny but might be a C4?
Fleet Mechanic
Joined: Sep 2003
Posts: 1,716
Likes: 15
Lotta' questions!
C4 has a rectangular pan. C6 has a pan with a notched right rear corner, it is not straight across the back or the right side. The vacuum modulator fits on the notched area at the back.
C6 is a 3 speed, with 3rd gear 1:1 ratio.
There is no lock-up of any sort back then (nor was there ever in a C6), so even in 3rd gear, where the ratio is 1:1 the torque converter is still in play. That's good for staying up in 3rd under load. But there is loss in the torque converter, which will show up as the engine turning slightly faster than the C6 output shaft.
If you tell us what RPM you are running at 60 MPH or so, what rear end ratio you have, and what OUTSIDE tire diameter for rear tires, we can give you a guesstimate on what RPM is reasonable.
Not clear by what you mean by "will not go into 1st". Will the lever not move over there, or does is move, but something else happens?
C4 has a rectangular pan. C6 has a pan with a notched right rear corner, it is not straight across the back or the right side. The vacuum modulator fits on the notched area at the back.
C6 is a 3 speed, with 3rd gear 1:1 ratio.
There is no lock-up of any sort back then (nor was there ever in a C6), so even in 3rd gear, where the ratio is 1:1 the torque converter is still in play. That's good for staying up in 3rd under load. But there is loss in the torque converter, which will show up as the engine turning slightly faster than the C6 output shaft.
If you tell us what RPM you are running at 60 MPH or so, what rear end ratio you have, and what OUTSIDE tire diameter for rear tires, we can give you a guesstimate on what RPM is reasonable.
Not clear by what you mean by "will not go into 1st". Will the lever not move over there, or does is move, but something else happens?
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Thanks for the info......
Yes my shift leaver on the column will not move into the 1 st. gear position on the indicator.
My trans pan is square with 11 bolts. (C6?)
It shifts thru 3 gears , little hard but it does go 3 shifts.
I will put a tach in there and get the RPMS.
My rear is a 3.25 by the book. , so with stock 15 in. tires
I should be at about 2800 - 3000 rpm's at 60 MPH.
I will check it out with a tach later.
Thanks
Yes my shift leaver on the column will not move into the 1 st. gear position on the indicator.
My trans pan is square with 11 bolts. (C6?)
It shifts thru 3 gears , little hard but it does go 3 shifts.
I will put a tach in there and get the RPMS.
My rear is a 3.25 by the book. , so with stock 15 in. tires
I should be at about 2800 - 3000 rpm's at 60 MPH.
I will check it out with a tach later.
Thanks
Fleet Mechanic
Joined: Sep 2003
Posts: 1,716
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This is what a C6 would look like:
[IMG]
[/IMG]
Note the notch in the pan. Where I have the black hose with the red golf tee shoved in it, that is where the Vacuum Modulator normally attaches to the case.
If the column lever won't go over to manual first, you could try blocking the wheels and disconnecting the shift linkage from the lever down at the trans. Leave the lever on the trans. Grab the trans lever, and see if you can click it through all positions that should be there. If so, then check out the linkage, and maybe the detent in the column, if there is one.
Be careful after connecting it back up and starting it. In case you are off by one position, and it starts and takes off in reverse! In other words, keep left foot firmly planted on the brake!
[IMG]
[/IMG] Note the notch in the pan. Where I have the black hose with the red golf tee shoved in it, that is where the Vacuum Modulator normally attaches to the case.
If the column lever won't go over to manual first, you could try blocking the wheels and disconnecting the shift linkage from the lever down at the trans. Leave the lever on the trans. Grab the trans lever, and see if you can click it through all positions that should be there. If so, then check out the linkage, and maybe the detent in the column, if there is one.
Be careful after connecting it back up and starting it. In case you are off by one position, and it starts and takes off in reverse! In other words, keep left foot firmly planted on the brake!
Last edited by Torky2; Dec 4, 2003 at 12:12 AM.
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"Be careful after connecting it back up and starting it. In case you are off by one position, and it starts and takes off in reverse! In other words, keep left foot firmly planted on the brake!"
I know there is a good story behind this comment Torky2!
I know there is a good story behind this comment Torky2!
Senior User
Joined: Mar 2003
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From: NE TX
Yes, possibly shifter linkage problem because it won't shift to low on column and rpms are high in Drive. Could be that trans is actually only in 2nd when you think it is in Drive/3. Sometimes marker in dash pod can hang up or break but if this is the case you could still manually shift to low unless something in column linkage is binding. I would definitely check/adjust linkage at the transmission lever. And it could still possibly be inside the transmission. I've had problems before with shifters but mainly in a car w/2 speed shifter and converted to 3 speed trans or in an older F150 with manual 3 on column. BTW I had a lockup TC on my 81 F100 w/ C5. I went to C6 second time around though.
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Originally posted by wick246
I know there is a good story behind this comment Torky2!
I know there is a good story behind this comment Torky2!
The park/neutral switch was in the column, which was in park, which allowed the starter to operate. But the lever on the trans was one click over, in reverse. So when I started it, it immediately went in reverse.
This is an easy thing to do (messup, I mean) so I was prepared for it. Prepared, but surprised.
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