My 904 valvebody

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7dart0

7dart0

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I had an issue earlier with shifting but it was misadjusted bands.

So I was gonna move ahead with my transgo tf-3 install but my valve body doesn't look stock like everyone elses.

What do you guys think?

Along with the kit I was going to remove the accumulator spring for firmer shift and use the blocker rod pros/cons to that?

Thanks

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My turbo action VB has a part # etched in the separator plate and says
turbo action under the part #
 
Of course you realize the stage 3 means that if you follow the kit and do everything you're going to have to shift it manually into every gear every time correct? As in if you start in 3rd it will start in 3rd if you start in second it will start in second?
 
I have no problem with a manual VB but be prepared for it trying to break your neck on every shift regardless of RPM
 
Yes I know. I had a turbo action reverse manual in my challenger. I'm fine with shifting.

Is there any chance I can change the reverse servo while the trans is in the car?
 
7dart0 said:
Yes I know. I had a turbo action reverse manual in my challenger. I'm fine with shifting.

Is there any chance I can change the reverse servo while the trans is in the car?
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To disassemble the rear servo the tailshaft will have to be removed and the pin that holds the rear band linkage pulled out so it'll let the servo apply lever drop out of the way. Getting it back together is sometimes a real PITA
 
It's been posted before that the reverse servo adjustment can be backed all the way off so the band strut can be removed; allowing the arm to swing out of the way. Push on the band upper tang with a screwdriver to pop out the little square strut plate. If the servo shaft seal is leaking, just chisel off the nub that stops the shaft from coming out, push it back far enough to remove the oring, blast it off with carb cleaner, dry, replace the oring and silicone it back in. They didn't have silicone in 61 when this trans was invented but now there are a lot of modern applications where silicone is used in leiu of gaskets or orings.
 
CudaFactHackJob said:
It's been posted before that the reverse servo adjustment can be backed all the way off so the band strut can be removed; allowing the arm to swing out of the way. Push on the band upper tang with a screwdriver to pop out the little square strut plate. If the servo shaft seal is leaking, just chisel off the nub that stops the shaft from coming out, push it back far enough to remove the oring, blast it off with carb cleaner, dry, replace the oring and silicone it back in. They didn't have silicone in 61 when this trans was invented but now there are a lot of modern applications where silicone is used in leiu of gaskets or orings.
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That works on 727's but not on 904's cause 904's have a much larger servo apply arm. Due to it's size it will not drop down enough to allow the servo to be disassembled
 
You got me thinking cuz it had been about thirty years since l had done one so l flipped over a 904 l had laying out in the yard and checked it. The pan was already off so all l had to do was back off the 9/16" nut and unscrew the adjuster, pushed up the band lug and popped out the strut, and the arm swung out of the way with room to spare. Maybe you're thinking of the double wrap band. I don't have one handy to check.
 
I remember when I put my stage 3 in last year it shifted perfect when I followed the instructions using a stock valve body. I think maybe an idea would be to just get a stock valve body and rebuild it with the stage 3 kit? Maybe find one used for 40 bucks or something. again one shifted perfectly it didn't shift too hard or too soft it just shifted with a nice firm shift. Basically it would shift a little harder the more RPMs you gave it basically the way you want it. Again though everything is manual. I used a quicksilver shifter and it was easy to ratchet back and forth.
It may be worth mentioning to say when you put the valve body back into put a new seal around the shifter leaver.
 
CudaFactHackJob said:
You got me thinking cuz it had been about thirty years since l had done one so l flipped over a 904 l had laying out in the yard and checked it. The pan was already off so all l had to do was back off the 9/16" nut and unscrew the adjuster, pushed up the band lug and popped out the strut, and the arm swung out of the way with room to spare. Maybe you're thinking of the double wrap band. I don't have one handy to check.
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The one I tried to do it on was indeed a double wrap band model. I haven't had any that weren't. The arm on them is larger than even a 727 trans. Was your 904 off a slant 6 or a V8?
 
This one was slant six. It's been a while but l'm pretty sure the double wrap doesn't have a strut that can drop out to increase clearance enough for the arm to swing out of the way. I never liked the double wrap because the adjustment is very loose and l felt that encourages piston misalignment.
 
CudaFactHackJob said:
This one was slant six. It's been a while but l'm pretty sure the double wrap doesn't have a strut that can drop out to increase clearance enough for the arm to swing out of the way. I never liked the double wrap because the adjustment is very loose and l felt that encourages piston misalignment.
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Your correct about the DW band not having a strut to remove. I know it specifies a much looser adjustment than the single wrap band but there's not really more clearance between the lever and piston to let the piston. The band due to it's design is more "springy" so it has to be looser. At least that's what I gather from looking at it. BTW I rarely go by the factory specified settings. I generally adjust the band so that it's just barely contacting the drum (felt while spinning the drum by hand) then back off till it doesn't touch. When I did the 904 in my car I used all premium parts due to it being behind a healthy 408 and if I remember right the rear band adjustment ended up at approx 3 turns
 
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