A904 Hard 1-2 Shift and Reverse

-
69 Barracuda vert

69 Barracuda vert

Active Member
Joined
Jan 22, 2021
Messages
43
Reaction score
20
Location
Sunny Atlanta
I recently acquired an "All Original" 1969 Barracuda Convertible 318 2bbl with only 68,000 miles on it. Rebuilding the entire front end (It's toast, everything rotted and loose) with a front disc brake conversion, manual brakes, steering and 3 speed A904. I am experiencing (cold or warm) hard shifting into reverse and from 1-2 especially accelerating slowly. However, going faster helps but is still hard shifting just not as much. I have never rebuilt a trans but I know it is in my near future. Could an off the shelf fluid additive prolong the trans life for now AND what is potentially causing the problem and what am I looking at replacing? Y'all are the experts, I am a newbie who is relying on your knowledge and experience to guide me to greatness. Thanks
 
I'm no trans expert, but an easy thing to check is the adjustment of the kickdown linkage. download your service manual at mymopar.com and follow the procedures. I would first check its operation before making any adjustments.

also post up a lot of photos! engine compartment, carb linkages outside car all angles, inside the car etc. that way we can all geekout with you on your new find.
 
Dana67Dart said:
kickdown linkage
Click to expand...
Is this what you are talking about? You crack me up with the photo suggestion, but I will post photos
upload_2021-1-30_12-48-18.png
 
Is reverse engagement also delayed; not just harsh? Did you check both sides of the dipstick and it shows full while running in neutral?
 
69 Barracuda vert said:
Is this what you are talking about?
Click to expand...
yes.

the harshness going into reverse might be looseness in the diff. with e brake on and engine off , put it into neutral and see how much rotation you can move the drive shaft. My 67 with 319,000 miles has a lot of wear in the diff so it sometimes sounds and feels like it is banging into gear in reverse.

as for 1-2 shift at light pedal i would still look at the linkage.
 
toolmanmike said:
What is the idle speed? Too fast of a idle and it will bang into gear. It could probably use a band and linkage adjustment.
Click to expand...
Hard to say without a tachometer. However, I turned the idle down quite a bit and reverse has settled down to normal now only 1-2 is hard shifting. I didn't realize how high the idle was, purrrrs like a kitten now. Thank you for that Mike
 
69 Barracuda vert said:
Hard to say without a tachometer. However, I turned the idle down quite a bit and reverse has settled down to normal now only 1-2 is hard shifting. I didn't realize how high the idle was, purrrrs like a kitten now. Thank you for that Mike
Click to expand...
Good to hear. If you look at the illustration above, the slotted rod should just slide over the pin setting in the idle position. If it is under spring pressure you can unscrew it until it is in the right position. The shift mph can be fine tuned from there. That is a good place to start. I myself like a firm shift but the transmissions don't last long if it's the opposite and slides into gear at a low mph.
 
Dana67Dart said:
yes.

the harshness going into reverse might be looseness in the diff. with e brake on and engine off , put it into neutral and see how much rotation you can move the drive shaft. My 67 with 319,000 miles has a lot of wear in the diff so it sometimes sounds and feels like it is banging into gear in reverse.

as for 1-2 shift at light pedal i would still look at the linkage.
Click to expand...

So, at the yoke of the transmission and the input shaft of the Ujoint (the small diameter) is about an 1/8"
 
toolmanmike said:
Good to hear. If you look at the illustration above, the slotted rod should just slide over the pin setting in the idle position. If it is under spring pressure you can unscrew it until it is in the right position. The shift mph can be fine tuned from there. That is a good place to start. I myself like a firm shift but the transmissions don't last long if it's the opposite and slides into gear at a low mph.
Click to expand...
trans linkage.jpg

The car is running and still choked. What do you mean by the "pin setting"
 
69 Barracuda vert said:
So, at the yoke of the transmission and the input shaft of the Ujoint (the small diameter) is about an 1/8"
Click to expand...
If I'm reading this correctly you are saying with trans in neutral, the drive shaft will rotate about 1/8 of an inch.

Mine will rotate about 1/2"

I don't think it's a worn diff!
 
Dana67Dart said:
If I'm reading this correctly you are saying with trans in neutral, the drive shaft will rotate about 1/8 of an inch.

Mine will rotate about 1/2"

I don't think it's a worn diff!
Click to expand...
The large diameter of the drive shaft, after the Ujoint at the trans, would move about a 1/4"
 
69 Barracuda vert said:
View attachment 1715680772
The car is running and still choked. What do you mean by the "pin setting"
Click to expand...
According to that photo, yes the choke is still on and it's still on fast idle. Run the engine until the choke butterfly is open and rev the engine a bit to get it off fast idle. It should be at curb idle and not on the step of the fast idle cam. (the short adjusting screw) The long screw is the curb idle screw.
 
toolmanmike said:
According to that photo, yes the choke is still on and it's still on fast idle. Run the engine until the choke butterfly is open and rev the engine a bit to get it off fast idle. It should be at curb idle and not on the step of the fast idle cam. (the short adjusting screw) The long screw is the curb idle screw.
Click to expand...
Yes it is on curb idle now. Where should the slotted rod be located when at curb idle?
 
69 Barracuda vert said:
Yes it is on curb idle now. Where should the slotted rod be located when at curb idle?
Click to expand...
The end of the slot should be at the pin to start with little or no drag. I would remove the return spring the clip and washer and try to slide the slotted arm off the pin. If it drags too much it's too tight and can cause firm or harsh upshifts. If it drags, slip it off and screw the end in and put it back on the pin. As I said, to start, the end of the slot should fit against the pin, no gap or tension. You can fine tune from there. Unscrewing the end will increase shift feel. Screwing it in will soften the shift. Only a turn or 2 at a time then test drive to see how it is.
 
I bet you can't open the carb all the way by hand, and you won't be able to push that slotted rod back any further. Take the slotted rod off the pin and turn it clockwise; shortening it; until you can open the carb all the way with the slotted rod installed.
 
toolmanmike said:
The end of the slot should be at the pin to start with little or no drag. I would remove the return spring the clip and washer and try to slide the slotted arm off the pin. If it drags too much it's too tight and can cause firm or harsh upshifts. If it drags, slip it off and screw the end in and put it back on the pin. As I said, to start, the end of the slot should fit against the pin, no gap or tension. You can fine tune from there. Unscrewing the end will increase shift feel. Screwing it in will soften the shift. Only a turn or 2 at a time then test drive to see how it is.
Click to expand...
This is without the return spring. So it is to loose and I need to get the right side (back) of the slotted arm just to the pin?

066.jpg
 
69 Barracuda vert said:
This is without the return spring. So it is to loose and I need to get the right side (back) of the slotted arm just to the pin?

View attachment 1715680848
Click to expand...
Try unscrewing it to close the gap. When the throttle is wide open, the linkage should be at it's furthest position. You would need to jack the car up with stands underneath and have a helper to test it that way.
 
toolmanmike said:
Try unscrewing it to close the gap. When the throttle is wide open, the linkage should be at it's furthest position. You would need to jack the car up with stands underneath and have a helper to test it that way.
Click to expand...
No drag at all! You are so awesome. Thank you for all your help. Out for a test drive.

067.jpg
 
toolmanmike said:
Try unscrewing it to close the gap. When the throttle is wide open, the linkage should be at it's furthest position. You would need to jack the car up with stands underneath and have a helper to test it that way.
Click to expand...
Took it for a test drive and I like it shifting at a higher speed however, it is still shifting hard into 2nd.
 
You must log in or register to reply here.
-

Back
Top