727 diagnosis help- wacky shifting

[dpstark2]

All,

I know this is going to be longer post and maybe vague- but I hope someone has some insight.

About two years ago, I put a B&M shift kit in my Charger's 727. I used the settings/instructions for "Street/strip." I air checked the trans, but did not disassemble the rotating assembly. It really firmed up the shifts, but the tranny wasn't doing exactly what I was hoping for. The 1-2 shift still came in a bit early, no shift came in very hard. I think, though, that the trans operated correctly at this point in time. I only drove it a few hundred miles this way.

Last year, while building a 440 to replace my 383, I also installed (from A&A trans) a 1-2 shift spring to raise the 1-2 shift point to match the 2-3 shift point, a 4.2 kickdown lever, and a 5800 rpm governor. I also put a 2400 rpm converter in the car, and had to swap over to a Lokar kickdown cable due to the TTI headers I installed.

At first, there were some issues with the kickdown cable. I had to redrill the throttle lever on the transmission to get the lever throw at the Edelbrock carb and trans to match. That is sorted now and I believe there are no issues with those settings.

Enough background- here are the issues I'm having and want to correct:

1. 1-2 shift occurs at about 22 mph under very light throttle, and 2-3 at 30 mph. These seem really high to me (even with 3.23 gears). Full automatic shifts at WOT do come in around 5500 rpm (close enough).
2. The trans will kickdown 3-2 only above about 45 mph. It will not do a 2-1 or 3-1 kickdown ever.
3. It rarely if ever automatically drops to 2nd after decelerating. If you get to 15 mph, it goes to first and first only.
4. Finally, if you manually shift 1-2 at, say, 30 mph under light throttle, the shift is delayed 2-3 seconds. A manual 2-3 shift occurs immediately.

I believe the automatic downshift and high 1-2 shift point are due to the 1-2 shift spring. I can kind of live with that or undo it at some point. The lack of automatic downshifting, manual 1-2 shift delay, and lack of 1st gear kickdown are my main issues.

I have checked fluid levels, governor pressure, kickdown adjustment, and every combination of speed, throttle, and gear selection I can think of and I am stumped. I understand the hydraulic diagrams well enough, and I keep thinking this has something to do with the 1-2 shift spring, something I did wrong in the shift kit, or a problem unrelated to the valve body.

Sorry for the length- if more info is needed, please let me know.

-Doug

 

[racedodge]

did you adjust the line pressure spring according to B&M spec's using their little paper ruler?

 

[dpstark2]

I did. And I've checked it since then too. I pulled the valve body, disassembled, and cleaned it, and double checked everything. Rick at A&A said to measure line pressure since that's the only way to really know, but I can't measure it because of the headers. Since the issue is so specific, I tend to think it's not such a general issue like line pressure.

in my research, I also came across the issue of check ball #6 in the B&M instructions. It says to remove it for HD and race applications, but not street-strip... Does anyone else thing that's weird? It controls flow to the accumulator and kickdown servo, which I think is the source of the issue. With the ball in and accumulator blocked off, there is a restriction in the oil line to the kickdown servo that could be causing the delay I'm experiencing.

I think I either have leaking rings on the kickdown servo or accumulator, or that check ball is supposed to come out. If I take this thing apart again, I'm going to remove that ball and replace the servo and accumulator rings.

Thanks for the reply!