904 wont up shift

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krabysniper

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Hey, I have a 904 that has been rebuilt (by myself and a friend) with a TCI Trans Scat performance kit, also made mods to the gearing (used an article from a mag about swapping parts from an A999 actually ended up getting the parts from a 78 newer lock up style 904, so now I have 5 clutch main hub, and lower gearing in first and second) am also using a converter from the slant six and 904 that were originaly in the dart, am using this set up behind a 360 thats got a single plain Streetmaster intake, Holley 600 vac secoondaries, headman 2 5/8ths headers, crane c cam.

My problem is that everything works excellent, shifts HARD from first to second, but won't shift into drive until what I think is about 40 45 mile per hour (speedo still aint quit right even after all the math and a new speedo pinion, grrrrrrr.) Shifts very very firmly into drive just dosn't do it till I am haulining. Fluid level is fine, pulled the valve bodie and double checked everything twice, I am almost 99.9% certain I have the kick-down linkage adjust correctly. Any body else ever have a simialar problem and what was your cure?
 
Kick down is still out of adjustment.
 
Sounds like the kickdown linkage isn't adjusted properly or the ratio is way off. It should be all the way back at wide open throttle and maybe just a tad before it. Otherwise things that could cause it would be govenor or valve body valves sticking. If you adjusted the screw on the side of the valve body that hold the throttle pressure valve from coming out then you have effectively raised the pressure, this will delay the upshift no matter what you do to the linkage.

As there are a lot of mismatch parts there and I'm not sure how you put it all together you could also be losing pressure around the reaction shaft seal rings.
 
Guitar Jones said:
Sounds like the kickdown linkage isn't adjusted properly or the ratio is way off. It should be all the way back at wide open throttle and maybe just a tad before it. Otherwise things that could cause it would be govenor or valve body valves sticking. If you adjusted the screw on the side of the valve body that hold the throttle pressure valve from coming out then you have effectively raised the pressure, this will delay the upshift no matter what you do to the linkage.

As there are a lot of mismatch parts there and I'm not sure how you put it all together you could also be losing pressure around the reaction shaft seal rings.
Click to expand...

Not mismatch, upgraded, modified, hot rodded, but definatly not mismatched.
Refrence an article in March 1998 High Performance Mopar called "Torque It Up" pages 14-15 and 78. Article talks about swapping in 2.74:1 low gear and 1.54:1 second gear in place of the stock 2.45:1 low and 1.45:1 second gear. Third gear remains 1:1. The parts are supposed to be found in an A999 transmission, but I discovered that some of the 78 and newer 904's with lock up also have the right gears AND had a 5 clutch high gear drum. SO now I have 5 clutches in my high gear drum, 4 in my second, and the gear ratio that in essence makes my 3:23's seem more like 3:55's in first and second gear but still give me highway milage of the 3:23's in drive.
As I have said though, drive comes in way late and I am worried that it may be doing it harm. I will try playing with the kick-down(thottle presure rod).
All I can say is when I get the bugs worked out, this is gonna be one hellaciously fun little 360 packed A body.

As to what you comment about the throttle pressure valve adjustment screw, I set it to what the Trans Scat performance kit instructions said to adjust it to, 1/8" between the valve and the throttle lever shaft piece that would other wise contact it. Does anybody else think that that might be wrong?
 
krabysniper said:
Not mismatch, upgraded, modified, hot rodded, but definatly not mismatched.
Refrence an article in March 1998 High Performance Mopar called "Torque It Up" pages 14-15 and 78. Article talks about swapping in 2.74:1 low gear and 1.54:1 second gear in place of the stock 2.45:1 low and 1.45:1 second gear. Third gear remains 1:1. The parts are supposed to be found in an A999 transmission, but I discovered that some of the 78 and newer 904's with lock up also have the right gears AND had a 5 clutch high gear drum. SO now I have 5 clutches in my high gear drum, 4 in my second, and the gear ratio that in essence makes my 3:23's seem more like 3:55's in first and second gear but still give me highway milage of the 3:23's in drive.
As I have said though, drive comes in way late and I am worried that it may be doing it harm. I will try playing with the kick-down(thottle presure rod).
All I can say is when I get the bugs worked out, this is gonna be one hellaciously fun little 360 packed A body.

As to what you comment about the throttle pressure valve adjustment screw, I set it to what the Trans Scat performance kit instructions said to adjust it to, 1/8" between the valve and the throttle lever shaft piece that would other wise contact it. Does anybody else think that that might be wrong?
Click to expand...

The problem is, is that the five disc clutch drum doesn't fit with the early non lockup reaction shaft. It bottoms out on the back side. In addition the drive lugs for the front clutch on the rear clutch drum may not be long enough to engage all five discs properly. If by chance you have the newer reaction shaft you also need the newer rear clutch drum as the small seal ring on the hub of the rear clutch drum is a different size, and this may be where you are losing pressure. Or you also need the newer two seal ring non lock up input shaft (difficult to find) as the single ring older design won't work either.

That is why I said mismatched as there is a lot of little things there to get right and some of those parts aren't very common.
 
Well I am not going to dispute that there are diffrences, I can atest that none of those concerns occured in the assembly of this trans, and now that you mention losing pressure, it got me to thinking and rereading some of my manuals and I think I have discovered the answer to my own question. I failed to make certain that the kickdown valve was pushed in all the way (it failed to mention it in the Trans Scat instruction sheet) when I set the distance from the throttle pressure cam to the kickdown valve. In other words, my kickdown is STILL not set right, GRRRRRRRR. Oh well, gonna go pull the pan and valve bodie for 4th time since gettin it in the car, and fix it, I am gettin good at doing this part :p Thanks for the help. Will update once I make this adjustment.
 
Well depending on the parts you used you may not have noticed the differences. Did you hand select each seal ring and test fit it to both assemblies before assembling it? If you didn't you could have mismatched parts and not even know it. I'm just trying to make you aware of the possibilities that could exist, not undermine your ability.
 
Well it wasn't anything to do with the valve bodie nor the kick down linkage, I am absolutly certain that both are right on, also removed restrictor plug from the front clutch feed hole, still no high gear till 50. Buddy of mine has talked to some transmission "guru's" and supposedly they believe that it's the gov. They say we should take out the gov thats in there and put the one in that came with the tranny that we got the low gear sets from. Something else I failed to mention was that as you decelerate it will shift down from high to second at around 35 or so and again from second to low at roughly 20, and it's a very firm jerk when it does. Any further opinions.

Not sure about what I am getting for stall as I don't have a tach in this car.
 
Hey all, just an update on my particular problem. Swapped in the govenor from the trany that I got the low gearset from AND installed ANOTHER speedo pinion (so's to have a better idea as to what speed I am actually traveling at and what speed things are happening at. Speedo pinion has me at 5 mph fast on the speedo meter, govenor has me shifting into drive at 35 mph, it still absolutely will not shift up into drive until I attain that speed but at least it's not 50 mph. Have done some reading and talking to some peeps and have come to the conclusion that the reason it wont shift untill 35 is due to a piece added to the tranny when I instaled the shift kit, was supposed to allow me to shift it into low gear at ANY speed (and it does!) I feel that this is probably the source of my problem but the govenor did at least make it shift sooner than it was and it basicly allows normal opertion the rest of the time, so I guess I will just live with it till something either breaks or I get a bug to take it apart agian for some dumb dam reason (NOT :eye: ) Anyway, if anyone else gets the urge to try this type of mod drop a PM my way with any questions and I would certainly try to help, it does make it a WICKED ride compared to what it woulda been. If any of you are from N.D. or Minnesota let me know and maybe we can get together and compare rides, drink beers, or maybe even run'em!
 
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