Hi I have a harsh 2-3 shifting issue with the 727 I just rebuilt for my 68 Charger 383. I installed a transgo tf-2 kit, 2400 stall converter, billet rear servo, sonnox accumulator, 3.8 lever and solid red lined kickdown band. All other parts are stock. The 1-2 shift is great. It's slightly firm under light throttle and gets firmer the more you keep your foot in in. However the 2-3 "bangs" every time. The shift seems quick and the rpms don't flare between gears... It's just the harshness of the shift is definitely excessive. It makes no difference if I'm accelerating very lightly or hard. I called transgo and they think I have a overlap issue. Thy said I need to install a additional spring in the kickdown servo. I have the one inner small spring in the servo. They said I should install an additional outer to release the band quicker. The manual shows the 440 and 383 HP cars only use one inner spring so I don't see why this should not work in my application as my car came with one spring from the factory. I'm thinking the band should be backed off but I already backed it off 2.5 turns from 72in lbs. Any suggestions?
727 harsh 2-3 shift
- Thread starter Bkl89
- Start date
I just rebuilt my 727, and put in a TF-1 kit. The kickdown servo small spring was replaced with the larger spring in the kit. Did you do that like they asked? Also, did you rebuild the entire transmission? If so, did you put the same amount of friction discs/steels in the clutch drums? Did you measure the spacing in the clutch drums to see if they were excessive?
Thanks for the reply. Yes I did rebuild the entire trans. Replaced all the bushings, seals and oil pump and checked every clerance possible. The front clutch has 5 thin red frictions and the clerance is .080. The tf-2 came with a spring for the low/reverse servo I installed. It didn't come with a spring for the 2nd gear/kickdown servo which doesn't make sense
lewtot184
Well-Known Member
i have a 727 with a tf2 kit in it and 2-3 is harsher/tighter than i like. pretty sure i'm getting a bunch of overlap with the 2-3 shift. you probably installed the welch plug in the trans body. i really think the problem is that heavy throttle pressure spring that the tf2 has. tf1 doesn't have that spring and i think they shift cleaner.
I think your right the line pressure may have a lot to do with the overlap. When I took my 727 apart for a rebuild I noticed someone had already installed a restriction plug for the 3rd gear feed and drilled the valve body the same as the transgo kit instructions said to but there was a stock line pressure spring. I instated the new spring that came with the tf-2 during the rebuild. I never had any overlap before the rebuild and now I do. I wonder if I should put the stock spring back in?
lewtot184
Well-Known Member
do the stock spring. a week ago i had the pan off mine and should've taken that heavy spring out; like a dummy i didn't! the tf1 is a much better kit if your going to drive. the best driving/performing valve body i ever had was the later part throttle kick down with a tf1. on the tranny with the tf2 i had to back the throttle pressure/kick down adjustment way down just to get the thing to upshift at WOT.
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