904 transmission issues

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HR5058

HR5058

FABO Gold Member
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I have a built 904 transmission behind a GEN three hemi. The shifter linkage bracket on the transmission is very hard to move. When I unhook the shifter linkage from the bracket, the shifter and cable moves just fine, but when I put it on the bracket it binds and won’t move with a lot of effort. I checked for clearance on the bracket to the case and there is no interference. I even moved the bracket up a little and it did the same thing. I have the adjustment dead on. I’m stumped on what it could be. This is a fresh transmission rebuilt. Any ideas? Thanks Chuck
 
What shifter are you using?
 
There should be two pins protruding from the transmission case. On the outer one is the shift lever. On the inner one is the combination throttle pressure/Kickdown lever.
I'm assuming the inner one, commonly called the K/D lever is working fine.
If the outer one, the shift lever, is binding even with the shift cable removed, and the lever is not mechanically rubbing on the case; then, I think the NSS needs to be backed off a lil and see if it smartens up. If it does, just put a fatter gasket on it or whatever it takes. If you take it out, expect fluid to come out. But if this fails to solve your problem, and the NSS ball moves in and out smoothly by your thumb,
then, IMO, the ValveBody needs to come down, and the manual valve and/or the "roostercomb" , inspected.

If the shift lever only has trouble coming out of park; that's a different problem. If the vehicle is parked on an incline, the park rod can jam in it's track by virtue of the weight of the vehicle transferring to the driveshaft and from there to the parking pawl. This is normal.
If the shift lever only has trouble going into park, this too is a different problem. The cogs on the parking pawl are fairly far apart and don't always line up. Sometimes the vehicle just needs to roll an inch or two in either direction, and then it jumps in. This too is normal.
But in either case, the shifter should not be seeming to bind or move with difficulty, as that would be ........ a different problem.
 
Last edited:
AJ/FormS said:
There should be two pins protruding from the transmission case. On the outer one is the shift lever. On the inner one is the combination throttle pressure/Kickdown lever.
I'm assuming the inner one, commonly called the K/D lever is working fine.
If the outer one, the shift lever, is binding even with the shift cable removed, and the lever is not mechanically rubbing on the case; then, I think the NSS needs to be backed off a lil and see if it smartens up. If it does, just put a fatter gasket on it or whatever it takes. If you take it out, expect fluid to come out. But if this fails to solve your problem, and the NSS ball moves in and out smoothly by your thumb,
then, IMO, the ValveBody needs to come down, and the manual valve and/or the "roostercomb" , inspected.

If the shift lever only has trouble coming out of park; that's a different problem. If the vehicle is parked on an incline, the park rod can jam in it's track by virtue of the weight of the vehicle transferring to the driveshaft and from there to the parking pawl. This is normal.
If the shift lever only has trouble going into park, this too is a different problem. The cogs on the parking pawl are fairly far apart and don't always line up. Sometimes the vehicle just needs to roll an inch or two in either direction, and then it jumps in. This too is normal.
But in either case, the shifter should not be seeming to bind or move with difficulty, as that would be ........ a different problem.
Click to expand...
I did take the neutral safety switch out and it didn’t make a difference. I should’ve said this is a reverse valve body with pro brake. I’m with you, I think I need to pull the valve body out as I think there must be something internally screwed up. I virtually have to take a hammer to tap on the bracket in order for it to move.
 
HR5058 said:
I did take the neutral safety switch out and it didn’t make a difference. I should’ve said this is a reverse valve body with pro brake. I’m with you, I think I need to pull the valve body out as I think there must be something internally screwed up. I virtually have to take a hammer to tap on the bracket in order for it to move.
Click to expand...
Ok!, Keep us posted.
 
Are there any sharp bends? like 180 degree type. Some shifter cables will bind when they have those tight radius bends.
I am using a SCS Cheetah by Turbo Action on my 904 reverse valve body, for some reason their cable is able to handle tight bends.
Another option is precision shifters, PPP shifters they are available from https://www.coperacingtrans.com/

Good luck with your project
 
Just to be clear...

With linkage removed the lever on the trans moves freely. As does the shifter and it's linkage.


Only when the two are connected does it bind?
 
dana, the way i read it, is when the shifter cable is unhooked from trans, shifter and cable move easily. and when he hooks cable to valve body arm, it binds. but that is the way i take it. i might be wrong.
 
I am now really confused. Are you calling the arm that bolts to the valve body portion that sticks thru the case, a bracket. Pics would help.
 
rbkt65 said:
I am now really confused. Are you calling the arm that bolts to the valve body portion that sticks thru the case, a bracket. Pics would help.
Click to expand...
Correct

image.jpg
 
Valve body is off and shifts fine so somewhere it’s binding. Must be the piece, sorry I don’t the correct term, that the shifter bracket attaches to is binding in the case hole
 
When the cable is installed on this arm/lever, it is hard to shift, correct? When you try to move the arm/lever without the cable hooked up, is it still hard to move, as I think you stated above? If so it is in the valve body. Another thing that is possible, a 904 parking lever is different than a 727. If those are mixed up, problems occur.
 
After taking the valve body off, it looked like it was binding going through the case. I cleaned up the piece that goes through the case oiled it up and it moves freely now. At least so far. Thanks everybody for what to look for, we’ll find out tomorrow after I get a new pan gasket to see if it actually worked. Chuck
 
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