727 B&M shift kit problem

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hawaiiandart

hawaiiandart

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Any transmissions experts out there?

Installed a B&M shift kit using the "Street" mode. The old B&M shift kits used to call this "Street/Strip". It revs, like a false neutral, on the 1st to 2nd gear shift if shifted manually. When left in drive it shifts good even at full trottle but does not break the tires loose like I've experienced on other cars. The 2nd to 3rd gear shifts are good whether shifted manually or left in drive at full trottle. I've been told to take out the cupped orfice plug. The B&M instruction's Trouble Shooting Guide" says to remove the cupped orfice plug if the engine revs on the 2nd to 3rd shift but my problems is the 1st to 2nd gear change and only when shifted manually. Any body had this happen to them? I've been told locally to remove the cupped orfice plug but thats not that easy.

Any ideas???:help:
 
The cupped plug is for the 2-3 shift. Won't have any affect at all on the 1-2 shift. If your 2-3 shift is good now don't mess with the plug. I gotta be honest though and say even though I've rebuilt numerous torqueflites and used several different shift kits I haven't ran into that problem. I have ran into the opposite where it overlaps when manually shifted but never had one flare up when manually shifted. What all did the shift kit contain? Did it have you do any mods on the rear band servo? Did the trans. work right before installing the shift kit? Did you adjust the front band and if so how many turns out?
 
fishy68 said:
The cupped plug is for the 2-3 shift. Won't have any affect at all on the 1-2 shift. If your 2-3 shift is good now don't mess with the plug. I gotta be honest though and say even though I've rebuilt numerous torqueflites and used several different shift kits I haven't ran into that problem. I have ran into the opposite where it overlaps when manually shifted but never had one flare up when manually shifted. What all did the shift kit contain? Did it have you do any mods on the rear band servo? Did the trans. work right before installing the shift kit? Did you adjust the front band and if so how many turns out?
Click to expand...
I've done this install at least 8 times before and had good results so I don't get it. But that was years ago when the "Street" mode was called "Street/Strip". The trans shifted OK before the install but I wanted the "bang" on the gear change so chose the "Street" set-up. The "Competition" mode requires full manual controls. This is a street car with occasional 1/4 mile visits.

I discarded the 1-2 accumulator spring then installed the natural servo spring that came with the kit in the front servo. Tightened the band 72-in. lbs, then backed off 1 1/2 turns.

On the rear servo I installed the shim from the kit. After re-installing the rear servo I used the new spring that came in the kit. I tightened the rear band to 72-in. lbs. and backed it off 3 turns. I then discarded the accumulator piston spring and reinstalled the piston. Next came the cupped orifice plug.

Do you think it has anything to do with the throttle pressure? I got tired of jacking the car up to get underneath to adjust the throttle pressure linkage because it was shifting early under light throttle during street driving so converted over to the early type linkage so I could do the adjustment from the engine compartment. This is the only variance that I did from my previous installs.
 
The throttle pressure adjustment can affect the shift alot so you might try cranking it down some more and see what happens. BTW: When you discarded the spring in the accumulator did you install a blocker rod to keep the piston from moving? If not that's a potential problem. I always block them with a rod (sometimes they come with the kit and sometimes you have to make one) mainly because I don't want the piston to bang hard when pressure is applied. Not positive it would cause the delay in front band engagement but it's possible.
 
Didn't put the blocker rod in since the instructions said it was for "COMPETITION". I'll try and do some ajustment with the throttle pressure. Thanks for the input.
 
Anytime you remove the spring in the accumulator you effectively disable it. Remember it's a cushion. When there is a spring present it works. When no spring is present it doesn't do any cushioning. And remember without a spring or blocker rod it's free to slam back and forth. By blocking it with a rod you prevent movement. That doesn't make it shift any harder than it would without a blocker rod. Just prevents the piston from slamming around causing a possible failure. My suggestion is to block it even if the throttle pressure adjustment fixes the problem but do as you please.

BTW: Did the instructions say to remove the spring or did you just do that on your own?
 
Did this problem ever get resolved? I have a 1968 plymouth satellite 383 727 combo that does exactly the same thing. When manually shifting the transmissin the trans feels like it flairs or maybe gets stuck between 1 and 2nd . If you lift out of the the throttle it shift into 2nd and you are fine to do a wide open 2 to 3 shift. If you just leave it in drive, It shifts 1st to 2nd just fine and actually breaks the tires loose during the shift.
The motor is a stock bottom end 383 with a mopar purple .509 lift cam, holley street dominater manifold, edelbrock 625 carberator, headers, and mallory dual point distributer. It has a 3000 rpm stall conveter with a 3.9 sure grip rear axle. shifter is in good adjustment , I am considering going to a Turbo Action Manual valve body. I have a more potent motor on the stand that I am getting ready to put into it in the next couple of weeks. I want to make sure the trans will hold it. The new motor is similar to the old one except the 906 heads are ported and the pistons are forged 11 to 1 pieces. It is another 1968 383. I am also considering giving it a shot of nitrous.
 
........That is precisely y I do not use the B+M kit very much............Adjust both bands to 2 turns.....did u install the ball u removed from the vb cavity into the [I cant remember 4 sure] along with the 2 shift valve assembly?,.......yes the blocker rod will make it shift harder, but it will also help out ur 1-2 shift....u need both springs in the front servo....what year is ur trans and does it have the controlled load servo, if so u need to modify it.......kim........
 
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