Ok, I'll start off by apologizing for not searching past threads more thoroughly on this, I'm sure it is covered somewhere!

This is actually in an 89 c1500, but is the same as an f-body, so I'm sure someone can help me out!

Well, I had the transmisison all put together, ready to install, (I had gotten a core trans to rebuild while the vehicle was still being driven, the core just had the l/r clutches burnt, and the checkball for the l/r piston was stuck, which is what I figure the problem was. Other then that, the core trans was near perfect condition.) Got the truck to the shop, found out it had electronic speedo, therefore I had to pull the rebuilt trans apart and change the shaft. I had 100% confidence in the trans before the shaft change! Well, I got the thing back together a day or so later, and found out that I had no 2nd gear. Well, I remembered the servo going back in a little rough, so I figured I must've ruined a seal. Well, I was hoping that somehow this was also keeping the thing from working in OD. If I out it in D, everything is fine, and after being in D, I could go to OD with no problems.

Well, I got the servo problem fixed, and everything was good except the OD issue. In OD however, if I rev it, it seem to be trying! I took the truck down the road, and the engine died on me. Battery was too weak to restart it, I had to walk about a mile in about 30* windy weather. Now I'm slightly angered....Get a ride back up the road, jump it, put in gear, ran it a little hard, now I have nothing but 1st gear. No second, no skip into 3rd, just first. If I put it into 1, I get the L/R clutch providing engine braking, but that's the only change. Also, reverse is fine.

Am I gonna have to pull it again? I've done several 4L60E's without the first problem, and some of them were BAD...This is the first 700 I think I've done (Can't remember doing a complete rebuild on one before!) I've only been doing tranny's at the shop for aboput 2 years, therefore I don't have a large amnount of experience. I remember reading somewhere that inout sprag could cause this, is this possibly my problem, or could I have just missed a checkball in the valve body? It is a newer aux valve body trans..

Please help me! This is a job I'm doing to help a buddy out, and I'm losing my a$$ (Not to mention my mind!)

 

Oh boy, where to start. I guess we'll start from the beginning:

The "stuck" checkball wouldn't cause the clutches to burn out. It sits in a double orificed capsule. The point is to force fluid through orifices on both sides of the checkball seat, yet allow exhausting fluid to free flow. I see alot of checkballs get stuck between the two tangs. It will just cause a faster apply of the lo-reverse piston, which can cause a "double bump" on apply as the reverse input clutches are still orificed.

As far as the not starting in OD issue, it does sound like a foward sprag issue. I would say that it may have been installed backwards, but you would have some major internal binding occuring when you finally got it into 4th. Since you said you eventually got it into 4th and didn't notice anything unusual, I'd say thats not the problem (being backwards). Other than that, perhaps the sprag is slipping (since you said it feels like its trying). By putting it in "D" or manual third, you are applying the overrun clutches which will override the sprag allowing you to pull foward.

It sounds like you fixed the no 2nd gear concern by replacing a possible torn servo seal. Did you see anything wrong with it when you took it out?

So now your down to just having 1st and reverse. How far have you tried winding this thing out? I have seen the Throttle Valve stick on "fresh rebuilds" way to many times. Its nothing you did wrong, its just one of the common problems w/ the 700R-4. Thats why I harp on the TransGo kit so much. Try yanking on the TV cable a few times and re-adjust it. Its not really a fix, but I have been able to restore normal operation after a stuck valve by doing this. You don't even have to buy the expensive TransGo kit, TransGo makes a smaller kit that contains the TV fix. I hope thats all it is.
Another thing that it could be, is that when you replaced the output shaft, you may have stretched out the snap-ring and it may have popped off. When the output shaft is allowed to slide rearward, it looses engagement of the governer and will cause a no-upshift, and usually damages the governer gear in the process. Yank the governer out and see what you can see.

And its not going to be a checkball. The purpose of the checkballs is to force fluid through an orifice during apply and allow free flowing exhaust fluid. Leaving one out will cause harsh engagement/shifts.

 

I did tear a seal on the servo. When I put it in after changing the shaft, it went in a bit hard, and I may have even forced it more than normal, I shoulda stopped and checked it out before doing damage, but I was in a hurry, as I only have time to work on it after hours at the shop, and I'm NOT gonna do it in the driveway at home. I have the transgo shift kit (I think it's the Jr.) to put in it, but once I had the thing together is when I remembered the kit! LOL Again, got in a hurry!

So, it boils down to: I need to pull it back out and put in a new sprag, and get the transgo kit in it. This sound about right? That's a good excuse to not go work on it tonight, I have to get parts (servo cover seal, sprag) anyway!

BTW....Should I be able to tell if the sprag is ok bu hand, or is it possible that it is bad and takes the torque of a running engine to make it noticealbe?

Thanks so much for you assistance! I hope to get to know more about these things one day! I have a good grasp on Chrysler transmissions, (they ARE all bad) I just haven't had as many of the GM tranny's apart!

Now, I just hope the 4L60E I have sitting in my garage that I put together for my V8 S10 project is ok! I know about the PWM problem (I have one to fix at the shop sometime next week) and some of the other stuff, I just didn't replace the sprags.

 

The condition of the overrun inner race should be smooth and in near perfect shape, the outer race should be roughed up, the sprag itself should be replaced in almost all cases to be on the safe side. The low/reverse roller sprag should be replaced also. Unless the unit has very low miles on it and you know its history, its not worth taking a chance. This should help you some, if you have any questions call me at 800 7763288.

 

I know it's been said many times around here, but thanks Dana from ProBuilt! Your experience was very helpful to me, and I thank you for sharing the wealth of knowledge with me! After speaking on the phone, I went back to the transmission, scrutinized the things you said, double-checked everything else, Put it all back together, then called it a day (at 10 PM). Put the thing in this morning, and Voila! Perfecto! My buddy isn't walking to work anymore, and I have one less headache!

Juts a note to everyone that doesn't already know....This guy knows his stuff, if he says something, I'd listen! I know I'll be looking to www.pro-built.net when I get ready to but the parts for the transmission in my Camaro!

 

M'Kay, so what fixed it?

 

Uhhhh, yeah....

 

Nevermind...