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Discussion Starter #1
Hello,


Recently we rebuilt the engine in this truck (83 6.2l 4wd 1/2ton Suburban with an automatic 700 Tranny). After starting up the engine for the firest time after rebuilding it, we discovered that the Transmission will not go in to any gear. The shift linkage is working and shifting the transmission lever, but it doesn't even attempt to go into gear. The detent cable and neutral safty switch are both hooked up, & there are no other hookups that go to the transmission.We had no problems with the transmission not going in to gear before this. Does anyone have any suggestions as to what the problem may be????


Thank you for your help,


jade
 

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I have a couple Ideas, first did you rebolt the torque convertor up? Had to ask.


I have bolted them together without the torque convertor slid all the way on. I think the last step is the pump, and without the pump, you'll get no movement. You can test it by pulling a cooler line and starting the truck. If it sprays all over, the pump is good.


The TV cable will do funny things, but it should still move. I have had the nut come off the back of the linkage inside the transmission case, but the shifter will feel very free.


There are broken input shafts, and bad torque convertors, but you should not be seeing that if it was okay before. Seen crankshafts break, they usually clank and know and make all kinds of noise.
 

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Discussion Starter #3
Hello,


Thank you for your help. I did get the tranny to start engaging. However now I have a new problem with the transmission. When driving it doesn't want to go over 35-40 miles an hour once it shifts into 3rd gear, it doesn't want to shift into over drive. No matter how much fuel i give her she just sits there at 35-40 miles an hour. Could this be an improperly adjusted detent rod or something worse? Any thoughts?


Thank you,


Jade
 

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The govenor in the transmission will overide the detent, or TV cable. So if you stand on the pedal hard enough it should shift up anyway.


Shifts go 1st, 2nd, 3rd, torque convertor lockup, 4th. If you are only getting 35mph you are in 1st or second. I can run 70 in 3rd.


You should be able to pull on the cable and get it to move with your fingers up where it connects to the linkage, or to the pump. You should be able to pull it, and it should have spring pressure pulling it back.


To properly set the cable, push down on the brass colored D shaped tab, slide the center piece all the way back as far as it will go towards the firewall, wish I had a picture again.


Get in a step on the pedal, push it all the way to the floor as hard as you can. You should hear the cable click a couple times. Then it is properly adjusted.


If the cable is too lose the trans will shift very early, at very low rpm's. If the cable is too tight it the engine will almost be reved against the govenor before it shifts.


When you disconnected the cable to pull the engine, did you take it off the tranny, or off the intake manifold? If you took it off at the tranny, it can be very difficult to reinstall properly without pulling the pan.


Try to readjust the cable first, see what that changes.
 

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Discussion Starter #5
Hello


I disconnected the TV cable from both the tranny and the mannifold. The reason I think the tranny is in 3rd when going 35 is because when i manualy shift to 2nd it obviously downshifts... so maybe that is another problem yet. I will go out now and try to adjust the tv cable and see if that helps. If not I will come back and let you know :)


Thanks for your help :)


Jade
 

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Is it possible you might be feeling the torque convertor unlocking when you downshift?


There is a pulse switch in the tranny that when you manually change the gear selector it unlocks the convertor. Kinda stupid I know.
 

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Discussion Starter #7
hi again,


Ok, I drove it again and kept a close watch on what was happening. The tranny will shift up to 3rd gear while driving normaly. If you lay on the fuel, it will downshift from 3rd to 2nd. But it just keeps reving in 2nd (and does not actually raise the mph once you reach 30-35), instead of shifting up to 3rd when you are at full throttle. If I let of the throttle, it will shift up to 3rd, but it wont actually accelerate any more, and it never reaches the overdrive gear. So, 35 is top end right now.


Thank you,


Jackie
 

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If it is the cable, it is too tight then. Did you find it and try to pull it to see if it moves at all? Make sure the metal section the connects the pump to the end of the detent cable isn't bent and binding up.


I can't remeber all the specifics, but it seems like where the cable goes into the transmission it is on a little bracket inside the pan, I can't remeber if you yank the cable too hard, or if there was some other condition that would bend that little bracket. When that bracket got bent It held the TV valve open in the tranny, which it is suppose to be closed until you step all the way down on the pedal.


If you are really adventureous take the cable off at the transmission, that should default the valve to closed, and it should start shifting way too early without kicking down. That would tell us may the cable is kinked or damaged. You would have to find a way to plug the hole it came out of though.


That is the only thing it can be besides something internal. Atleast that I can think of. It will be monday now, but call a tranny shop. Most of them will give it a free test drive, if you can get to them.
 

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Discussion Starter #9
Hi again,


The cable seems to move freely back and forth. The detent rod doesn't seem to be binding up, however it is slightly bent. I am really hoping that it is not something internal. I will try disconnecting the cable tomorrow in hopes that a stuck vavle is the cause. Thanks again for all your help and information



Thanks,


Jade
 

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I hope you find it, sorry I couldn't be more help.


I'm with you though, makes no sense it worked before, and now it won't.
 
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