SuperFlyTNT
Well-Known Member
Dear 727 aficionados,
I recently got my hands on a 72 Charger SE, original 400-2bbl. A previous owner replaced the factory induction with an Edelbrock Torker intake and Performer 4bbl carb.
The car has always had a 'late' upshift from 2nd to 3rd at part throttle, in the sense that you would have to get up to about 40-45mph with a cold engine before it would shift into 3rd. Even then, it would only shift I would lift my foot slightly off the throttle. It is a bit better (read: shift rpm is lower) when engine is warm at part throttle to WOT. The shift itself is not really noticeable. The car has the slap stik shifter, but I have not driven it yet with the slap stik to see how the shift feels from 2 to 3 when shifted manually.
Also with warm engine at part throttle and gradually speeding up I can feel the transmission acting similar to a shift overlap from 2nd to 3rd gear (as described by a Forum member in a different thread "like stepping on the brakes before shifting"). At least that tells me it is shifting to 3rd, but the overlap between the clutches has to be resolved for sure.
Now, would the shifting overlap and late upshift be related to one cause (as it happens both in 2-3 only)? For the late upshift my common sense tells me that there is insufficient hydraulic pressure buildup to have the transmission shift at a more common, lower engine speed. That could be caused by the throttle lever on the transmission to be in the 'incorrect' position at the time the engine rpm would normally cause the transmission to shift. Instead the pin on the carb needs to move the kickdown linkage and throttle lever further back.
If my assumption is correct, would adjusting the kickdown linkage also solve the shift overlap in this case?
Thanks in advance for any advice
I recently got my hands on a 72 Charger SE, original 400-2bbl. A previous owner replaced the factory induction with an Edelbrock Torker intake and Performer 4bbl carb.
The car has always had a 'late' upshift from 2nd to 3rd at part throttle, in the sense that you would have to get up to about 40-45mph with a cold engine before it would shift into 3rd. Even then, it would only shift I would lift my foot slightly off the throttle. It is a bit better (read: shift rpm is lower) when engine is warm at part throttle to WOT. The shift itself is not really noticeable. The car has the slap stik shifter, but I have not driven it yet with the slap stik to see how the shift feels from 2 to 3 when shifted manually.
Also with warm engine at part throttle and gradually speeding up I can feel the transmission acting similar to a shift overlap from 2nd to 3rd gear (as described by a Forum member in a different thread "like stepping on the brakes before shifting"). At least that tells me it is shifting to 3rd, but the overlap between the clutches has to be resolved for sure.
Now, would the shifting overlap and late upshift be related to one cause (as it happens both in 2-3 only)? For the late upshift my common sense tells me that there is insufficient hydraulic pressure buildup to have the transmission shift at a more common, lower engine speed. That could be caused by the throttle lever on the transmission to be in the 'incorrect' position at the time the engine rpm would normally cause the transmission to shift. Instead the pin on the carb needs to move the kickdown linkage and throttle lever further back.
If my assumption is correct, would adjusting the kickdown linkage also solve the shift overlap in this case?
Thanks in advance for any advice
