Hard Shift On 904

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805moparkid

805moparkid

Slant and AFX Guy
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ok so i have this swinger that i saved from a little old lady in 08. it had been sitting for at least 10 years in the same spot before that, and thats just as long as i can remember it. anyways it just ticked over 106K here a week ago, runs good, happy little car.

One thing its done since i got it is a hard 1-2 shift, like jaring. I can pull all the kickdown pressure out so it shifts a little better but my mpg falls like a brick. Something i noticed the other day was if you manual shift 1-2 after the D shift point its a perfect shift.

Only extra thing to add is it drains back really bad, after driving to work , 8am, till 5pm its got to fill again lol.

i was thinking of taking it to my tranny guy and have him do a shift kit so i could have him check and clean the vb, while adjusting bands. i can do the front bushing when i swap converters.

Any idea what would cause this?
 
The only thing I've seen cause a hard 1-2 shift is when the accumulator spring breaks or someone removes the spring under the accumulator and installs a blocker rod. This is an old school back yard type shift improver that mainly affects the 1-2 shift. I do this on cars with high stall converters in high HP apps because the converter softens the shift quite a bit but I never recommend doing it with a stock converter, or even one lower than 2200-2300 stall. Even then I warn the customer it may shift rough going into 2nd.

You have to pull the front pump to change the bushing, but that's not all that contributes to converter drain back. Worn reaction shaft sealing rings also lend to drain back. They can also be changed with the pump out. If you tighten the front band down good and snug it'll hold the clutch packs in place so you can pull the pump out to do the work on it. Just remember to re-adjust the front band after your done. A worn manual valve in the valve body would also cause drain back. Trans-go, as well as other mfg.'s has a manual valve kit that gives you a modified manual valve so it fills in park (although slowly). I use them in all the trans I do not just to make it fill in park but to replace the almost always worn out manual valve.
 
fishy68 said:
The only thing I've seen cause a hard 1-2 shift is when the accumulator spring breaks or someone removes the spring under the accumulator and installs a blocker rod. This is an old school back yard type shift improver that mainly affects the 1-2 shift. I do this on cars with high stall converters in high HP apps because the converter softens the shift quite a bit but I never recommend doing it with a stock converter, or even one lower than 2200-2300 stall. Even then I warn the customer it may shift rough going into 2nd.

You have to pull the front pump to change the bushing, but that's not all that contributes to converter drain back. Worn reaction shaft sealing rings also lend to drain back. They can also be changed with the pump out. If you tighten the front band down good and snug it'll hold the clutch packs in place so you can pull the pump out to do the work on it. Just remember to re-adjust the front band after your done. A worn manual valve in the valve body would also cause drain back. Trans-go, as well as other mfg.'s has a manual valve kit that gives you a modified manual valve so it fills in park (although slowly). I use them in all the trans I do not just to make it fill in park but to replace the almost always worn out manual valve.
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very cool thanks! does the manual valve kit come in the shift kit? and which one would you recommend (I/II)?
 
Valve Kit

[ame]http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=380801133636&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en[/ame]

Shift kits
(II)
[ame]http://www.ebay.com/itm/TransGo-TF-2-Shift-Kit-Automatic-Type-Chrysler-Torqueflite-Full-Race-Shifts-Each-/331092064281?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d169ff819&vxp=mtr[/ame]
 
It looks like the -2 comes with the valve, is that the correct valve? also i dont want it to drop into low at any speed so do i need a different spring? Lastly does this kit come with the accumulator spring i need to fix my 1-2 shift?
 
805moparkid said:
It looks like the -2 comes with the valve, is that the correct valve? also i dont want it to drop into low at any speed so do i need a different spring? Lastly does this kit come with the accumulator spring i need to fix my 1-2 shift?
Click to expand...

Yeah the tf-2 kit has the manual valve. It won't drop down into low at any speed unless you do the shift command mod. It's optional so you can skip it. Doesn't come with a spring for the accumulator. It tells you to use the stock one. If yours is missing or broken you'll have to acquire one. I have some for 727's but I'm not sure if their the same on 904's. If you can get me a diameter I can check what I've got and if I have one I'll send it to you.
 
I can post an older set of TF-2 instructions if you'd like to see what all they want you to do. There is a newer set of instructions but I don't have them but their very close to the same, just minor differences
 
fishy68 said:
Yeah the tf-2 kit has the manual valve. It won't drop down into low at any speed unless you do the shift command mod. It's optional so you can skip it. Doesn't come with a spring for the accumulator. It tells you to use the stock one. If yours is missing or broken you'll have to acquire one. I have some for 727's but I'm not sure if their the same on 904's. If you can get me a diameter I can check what I've got and if I have one I'll send it to you.
Click to expand...

well its my daily so I cant have it down for that long, i'll buy a new one and just have it ready to swap.

fishy68 said:
I can post an older set of TF-2 instructions if you'd like to see what all they want you to do. There is a newer set of instructions but I don't have them but their very close to the same, just minor differences
Click to expand...

yea that would be awesome! i guess its a little bit different that what i thought but hey, i can figure it out as long as i have all the parts!
 
805moparkid said:
well its my daily so I cant have it down for that long, i'll buy a new one and just have it ready to swap.

I hear ya.

yea that would be awesome! i guess its a little bit different that what i thought but hey, i can figure it out as long as i have all the parts!
Click to expand...

Dang! Files are too big to load here. PM me your e-mail address and I'll send it via e-mail
 
fishy68 said:
Dang! Files are too big to load here. PM me your e-mail address and I'll send it via e-mail
Click to expand...

done

any idea where to find a stock or upgraded accumulator spring? nothing on the transgo site or SMR, maybe transstar?
 
805moparkid said:
nothing

Bummer. I don't know anywhere else to look. Kim do you know if a 727 accumulator spring is the same diameter as a 904 spring?
Click to expand...

been to long since ive been in a trans, shuttle valve is the same as the main valve that controls manual shifts correct?
Click to expand...

No. It's a separate valve located on the top of the valve body
 
It's always a good idea to completely disassemble and clean and lube everything and make sure all valves move free in the valve body. If you do that you'll be fine. If you run into any galded valves time for a new VB. That doesn't happen very often.
 
..............Tracy, I've never had both together to compare, but I think they are not the same........I do know that the servo's are different sizes........I may have a 904 spring kicking around.....u could also contact Pat Blais aka torqueflitepatty.....I think he is in Tacoma or Seattle..........kim.....
 
I was thinking their a different size also but wasn't positive. I have a couple 904's in the garage I've been meaning to tear down and compare parts sizes but been too busy with family stuff. Hopefully get to it soon.
 
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