I've had it with this 904, about to give up!

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CultClassik

CultClassik

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Some of you have seen and helped me out before. After my last tinkering with the valve body, I thought I had this thing nailed. Problem was, sometimes it wouldn't go into gear. So you start it, wait or not for the converter to fill, put it in reverse, drive, low, whatever, nothing. Sometimes it worked no problem (but did have a strange shift flare, seems more pronounced under higher throttle). After I thought it was fixed, I was driving and turning at an intersection and it lost gear. You can rev, it doesn't move, acts like it's in neutral. I don't think it's slipping, when it does this is really doesn't know it's supposed to be in gear, the engine isn't loading.

Anyway, last night I cleaned up another valve body, put the TF-2 in it, checked everything, manual valve position etc, swapped it for the original (new is 73, original is 66). Felt really good at this, everything on it looked good, thought that I was going to pop it in and drive all over.

Nope. Fired it up, let it warm, filled back up with fluid, put it in reverse, nothing. Same problems. Won't go into drive, anything.

PLEASE, somebody tell me what is causing this crap. I'm really at my wits end. I thought it was surely the valve body, what else could it be??
 
What have you done for checks? Get "into" the shop manual and run some pressure checks. Might be a bad pump, etc.
 
The transmission, yes. Now, at the expense of being overly optimistic and also at the expense of my own pride, I let it warm up good and re-checked, the fluid was about 3 quarts low. So...maybe I'm just dumb. I drove it a bit since I posted this and it seems ok, but the shift flaring is really nuts. Now what I'm wondering is if the spring I put in the accumulator was the right one. It's got yellow paint, it's big, between the VB and piston..I was pretty good about labeling everything when I tore it down but it's possible I screwed up. The 1-2 shift flares up pretty nasty. 2-3 will also. I may pull the spring out all together and see what happens. I've been hesitant to do this but I figure it's worth a try and I won't have to disconnect the linkage etc, just drop the VB down a bit to get it out.

I thought it might have been something wrong in the VB, but since I did another, and it acts and drives exactly the same, I'm starting to think the VB is fine. Since the accum is supposed to cushion (just the 1-2 shift, right?) I'm wondering if that spring is just too stiff or something.
 
Try the pressure port test first. Hate to say it, trans will not live long behind flaring shifts. Ask me how I know. Stuff happens some times, worst case scenario tear it down again and see what's up. If anything screams a do over, it's a trans rebuild. A come along strap across the torsion bars works nicely to get it in and out.
 
I think with the TF-2 you don't use the accumulator spring, I believe you have to make it stationary with a piece of 3/8" rod.

Still have your directions??

Did you adjust your bands while you were in there?
 
I'll look up how to do the pressure test.

Bad Sport - the instructions say to put them back how they came out, but I've seen online lots of people say toss them out. A lot of people also say to put a rod but I don't understand how it would be placed in there.
 
and no I didn't adjust the bands since I rebuilt it, but I will do that when I drop the pan again!
 
mplex2000 said:
Bad Sport - the instructions say to put them back how they came out, but I've seen online lots of people say toss them out. A lot of people also say to put a rod but I don't understand how it would be placed in there.
Click to expand...

Fishy68 is online maybe he will chime in here.
 
Maybe I can shed some light on this.
Sounds like a low pressure problem to me. (Soft or no engage and flaring shifts)

Did you go through the pump?
Did you chk the pump stator ring surfaces inside the forward drum?
New rings on the stator? What kind? (Steel, Teflon)
Did you chk the ring lands and inner surface of the governor ring bore?

The accumulator is not going to cause it to act like that unless it was outright missing. :)

A REALLY good tell tale would be a mainline pressure test.
 
I did re-do the pump. I'll be honest I'm not sure how to check them, other than looking at the parts for excessive wear. The trans was in great shape when I rebuilt it with 79k miles, all original I believe but had been sitting out of the car so long and not driven since '79 that I went ahead and re-did the whole thing with red clutches and all the goodies. The rings in the kit I used were steel.

I will look at the FSM and see if I can manage a pressure test. I guess re-doing the pump isn't so bad. Aside from pulling the damn transmission :/
 
mplex2000 said:
I will look at the FSM and see if I can manage a pressure test. I guess re-doing the pump isn't so bad. Aside from pulling the damn transmission :/
Click to expand...


[ame="http://www.youtube.com/watch?v=jvzSpMuCvgM"]904 Torqueflite Air Check - YouTube[/ame]
 
Just the air check? I did that several times when I built it and it worked great. I thought we were talking about line pressure :p
 
Hey...so if they bands were way out...maybe? It seems to be ok going in to gear now, but you can never tell. ASSUMING that problem doesn't return, it could be the bands slipping, or am I wrong? Doesn't each band hold the drum while shifting (in it's respective gear)? I'm just trying to be smart and figure out possibilities.
 
Is the throttle pressure rod adjusted right? The rod must move as soon as the throttle moves. Did you set the pressure adjustment on the valve body per Trans Go's instructions. What are the clearances on the clutch drums? Were the drum seals replaced correctly? Did you adjust the bands correctly?

The accumulator spring holds the piston in the right place. The shifts are cushioned by hydraulic's. Removing the spring and putting in a rod won't fix the flairs. Check the pressure's and keep us filled in. Someone here will figure it out.
 
mplex2000 said:
Just the air check? I did that several times when I built it and it worked great. I thought we were talking about line pressure :p
Click to expand...

No, a mainline pressure test is done with the trans all together and the car running.
It tests the pressure that is being put out by the pump and pressure regulator valve.
One of the ports on the side of the trans is where you put a pressure gauge, and you can move the TP linkage and should see the pressure rise and fall.
I think it's the middle plug on the passengers side that is mainline pressure.

I know the TF2 kit tells you to adjust the pressure regulator valve on the valvebody by adjusting the allen screw.
Clockwise lowers the pressure, counter clockwise raises it.
Could it be that it was adjusted the wrong way?

Also as mentioned above, are you sure your TP linkage went back on the valve correctly?
Can you move the TP rod forward and backwards?
Try tying it all the way back for a quick test drive and see what it does.
It should go into gear real solid and not want to shift out of first.
 
mplex2000 said:
Hey...so if they bands were way out...maybe? It seems to be ok going in to gear now, but you can never tell. ASSUMING that problem doesn't return, it could be the bands slipping, or am I wrong? Doesn't each band hold the drum while shifting (in it's respective gear)? I'm just trying to be smart and figure out possibilities.
Click to expand...

If the second gear band was that far out it would skip second and shift from first to third.
It takes about 10 seconds of slipping to fry a band, so I doubt that it is actually slipping (You would smell it in the fluid)

The second gear band applies and stops the forward drum causing the powerflow to change paths and that changes gear ratio's and makes second gear.
The rear band does kind of the same thing as in redirects the powerflow through a planetary gear set reversing the powerflow giving reverse.
The rear drum not being held by the band gives first gear.

This shows how it all flows
http://www.carkipedia.com/automatic...saxles/chrysler_torqueflite_transmissions.php
 
Whoa hold on a second. The kit doesn't come with a new accumulator spring. It comes with two low/reverse springs. You need to reuse the accumulator spring and it goes between the vb and the accumulator piston. If you put the stiff heavy wound spring in the low side then maybe the rear band can't overcome spring and grip the drum. Could this be why?

Craig
 
Yes I checked the TP on both valve bodies, I don't think that's it. TF2 kit says to make the little deal flush. So PoisonDart, were you talking about the air check or the mainline check? I have the BPE kickdown cable kit, I'll try setting the lever fully engaged and see what happens.

my5thmopar - no the TF2 kit didn't come with a new accum spring and I had to go back thru the directions to make sure but it didn't come with a yellow spring. I was just making sure I put the right one in there, because when I saw the yellow spring last time I worked on it I was like huh...seems weird that spring is colored like the TF2 springs but came out of the original trans.
 
Would the piston seal in the front drum do this? I put one in one time and it felt funny so I pulled the piston back out and the seal had kinda rolled up the other way. Just a thought. If I read this right, you are on your 2nd VB so I wouldn't think it would be in that.
 
Im guessing hydo pump pressure. I had low fluid in a TH350 and it did that (actually it was a super clogged filter but starved the pump none the less) It would sort of drop into gear at a few revs then pop out. That or the pump seal rings,but the pressure test will tell.
 
gremlin said:
Would the piston seal in the front drum do this? I put one in one time and it felt funny so I pulled the piston back out and the seal had kinda rolled up the other way. Just a thought. If I read this right, you are on your 2nd VB so I wouldn't think it would be in that.
Click to expand...

Well,,, he said he air tested it and that would def show in an air chk.
(Assuming a person knew what they were hearing) No offence meant.

And a heavier spring in the accumulator wouldn't cause it, as it would just shift a little firmer as if you blocked it.

It almost has to be a mainline pressure issue in the pump or downstream from it. (shift flares and sometimes no engage)

And Pishta might be on to something.
There wan't any issues with the filter was there?
 
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