Transmission not shifting

[72ChargerHawkeye]

Okay so it seems like as soon as I fix one problem another arises on my 72 Charger with a 360 4bbl. Since getting my Charger I cleaned out the gas tank and lines, rebuilt the Edelbrock 600 cfm 4 barrel, changed the tires, changed the oil, and changed the plugs. After rebuilding the carb and swapping out fuel lines, I ran her around the block and she ran like new without a hitch. About a week after this I put her up on jacks and changed the oil and plugs. This is when Hurricane Irma hit our area. Right before the hurricane hit I drove her up the gas station down the road to top off with fuel. This is when I noticed something was off. It fires right up and about after a minute of running i can push all the choke off (Manual choke.) When driving down the road it was having issues shifting. When it went to shift the engine felt like it was bogging down and when it did shift it was like there was unused gas pumped into the carb and the car would lurch forward as if i had put the throttle to the floor. Today I whipped out the timing light because the engine is still coughing a little on a slow acceleration even in park. Timing was a little off and corrected the coughing but not the shifting. When my father and I installed this engine back in 2006 I put headers on it and had to go with a Lokar kickdown cable to clear the headers. Today I thought that maybe it was kickdown cable had gone slack on me over the past week (in my dreams). After downloading Lokar's manual for the cable I adjusted it as if it were a new install on the carb side (pulling carb to full throttle and pulling kickdown cable tight with no slack and tighting down the cable end stop flush with the kickdown throttle body fitting.) After doing this I took it out for another spin it seems as if this adjustment has now changed from a delayed shift to no shift. I am at a loss considering two weeks ago everything was working beautifully and after an oil change and plug change it is now not shifting right. Anybody have any suggestions?

 

[PP1RT]

Double check that adjustment. It doesn't sound right but I haven't used a lokar cable before.

 

[72ChargerHawkeye]

Vacuum line come off?

The vacuum lines from the carb to the distributor and the vacuum line from the carb to the pcv valve are both secure. I actually forgot that addition as well. Before the engine did not have the pcv valve and the 3/8" fitting on the carb just had a cap on it. I added a new hose and pcv valve. So I just went an removed the pcv valve and capped off the hose but still had the same result when I took it for a test run. Not wanting to shift.

 

[oldbee]

Double check that adjustment. It doesn't sound right but I haven't used a lokar cable before.

++1, plus maybe you got some water in the gas when you filled up?

 

[Yatzee]

Okay so it seems like as soon as I fix one problem another arises on my 72 Charger with a 360 4bbl. Since getting my Charger I cleaned out the gas tank and lines, rebuilt the Edelbrock 600 cfm 4 barrel, changed the tires, changed the oil, and changed the plugs. After rebuilding the carb and swapping out fuel lines, I ran her around the block and she ran like new without a hitch. About a week after this I put her up on jacks and changed the oil and plugs. This is when Hurricane Irma hit our area. Right before the hurricane hit I drove her up the gas station down the road to top off with fuel. This is when I noticed something was off. It fires right up and about after a minute of running i can push all the choke off (Manual choke.) When driving down the road it was having issues shifting. When it went to shift the engine felt like it was bogging down and when it did shift it was like there was unused gas pumped into the carb and the car would lurch forward as if i had put the throttle to the floor. Today I whipped out the timing light because the engine is still coughing a little on a slow acceleration even in park. Timing was a little off and corrected the coughing but not the shifting. When my father and I installed this engine back in 2006 I put headers on it and had to go with a Lokar kickdown cable to clear the headers. Today I thought that maybe it was kickdown cable had gone slack on me over the past week (in my dreams). After downloading Lokar's manual for the cable I adjusted it as if it were a new install on the carb side (pulling carb to full throttle and pulling kickdown cable tight with no slack and tighting down the cable end stop flush with the kickdown throttle body fitting.) After doing this I took it out for another spin it seems as if this adjustment has now changed from a delayed shift to no shift. I am at a loss considering two weeks ago everything was working beautifully and after an oil change and plug change it is now not shifting right. Anybody have any suggestions?

The transmission runs sort of independent of the engine except for the pull on the transmission pressure lever by the carb so one would suspect that the issue lies there.
As you probably understand, the pull on this lever increases fluid pressure in the tranny
creating shift points and keeping higher pressure on the bands and clutch plates to prevent slippage. The actual increase created by this pressure lever does not start from the "rest" position of the lever but rather about a quarter of the swing. This is the point where there is actual contact with the tip of the pressure slide valve inside the tranny. If you disconnect the cable from the lever and start swinging it by hand, you can actually feel this contact point, and that's where all adjustment begins. I can almost guarantee that there is too much play (slack) in the cable to the carb. When a shift rod was originally used, there was a long slot in it to ensure the throttle plates closed to idle, in a cable application you move the jacket of the cable forward or back to attain this slack. Worse case scenario with a cable is it is so far out of adjustment that you can't get WOT and idle at the same setting of the internal cable itself. Hold the tranny lever to it's max position and the throttle wide open and match the attaching ends at the carb. Then drive and notice your shift points. You can then adjust the cable sleeve or cable end a bit at a time (looser or tighter) to get the right shift points as well as kick-down. In your case I believe there's an end on the cable secured by a set screw - they have a tendancy to slip.

 

[drobertson]

I had the same problem in my 73 - had a 4 barrel on a 318 / 727 with the lokar kickdown. I had the kickdown set up like yours. Anyways my transmission I rebuilt didn't make enough fluid pressure, and it burnt up. I think yatzee is right. wish I knew about that 1/4 lever spin on the kickdown lever! Go ahead and try what he's suggesting before you lose your trans... It ain't fun

 

[oldbee]

I had the same problem in my 73 - had a 4 barrel on a 318 / 727 with the lokar kickdown. I had the kickdown set up like yours. Anyways my transmission I rebuilt didn't make enough fluid pressure, and it burnt up. I think yatzee is right. wish I knew about that 1/4 lever spin on the kickdown lever! Go ahead and try what he's suggesting before you lose your trans... It ain't fun

I know all about the intial slack in the throttle press and I believe it was setup like that on purpose. Not much of a real load on trans at low speed/throttle. I am lucky I guess that I still have original factory rods and don't have to resort to cable setup.

 

[drobertson]

I know all about the intial slack in the throttle press and I believe it was setup like that on purpose. Not much of a real load on trans at low speed/throttle. I am lucky I guess that I still have original factory rods and don't have to resort to cable setup.

I had the original rods (for the carter 2 bbl), but they would not work with the edelbrock manifold and carburetor. 4 barrel rods are getting hard to find, and re-pops are so damn expensive it's not worth it unless it's a 440 or hemi car.

I don't think there's a single problem with the cable system, minus the misleading instructions! It looks cool, too.

 

[72ChargerHawkeye]

The transmission runs sort of independent of the engine except for the pull on the transmission pressure lever by the carb so one would suspect that the issue lies there.
As you probably understand, the pull on this lever increases fluid pressure in the tranny
creating shift points and keeping higher pressure on the bands and clutch plates to prevent slippage. The actual increase created by this pressure lever does not start from the "rest" position of the lever but rather about a quarter of the swing. This is the point where there is actual contact with the tip of the pressure slide valve inside the tranny. If you disconnect the cable from the lever and start swinging it by hand, you can actually feel this contact point, and that's where all adjustment begins. I can almost guarantee that there is too much play (slack) in the cable to the carb. When a shift rod was originally used, there was a long slot in it to ensure the throttle plates closed to idle, in a cable application you move the jacket of the cable forward or back to attain this slack. Worse case scenario with a cable is it is so far out of adjustment that you can't get WOT and idle at the same setting of the internal cable itself. Hold the tranny lever to it's max position and the throttle wide open and match the attaching ends at the carb. Then drive and notice your shift points. You can then adjust the cable sleeve or cable end a bit at a time (looser or tighter) to get the right shift points as well as kick-down. In your case I believe there's an end on the cable secured by a set screw - they have a tendancy to slip.

Would this be the same for both the 727 and the 904? I still have a 904 in mine currently.

 

[oldbee]

Should be the same.

 

[furyus]

Also possible that you have the cable too tight. Try giving it a little more slack, and see if it shifts. Too much slack will let it shift too early. Too little slack will keep it from shifting.