[Regular6d]

Hey guys I'm working with a 700 R4 in an 83 K10, it was rebuilt a few months ago the original converter was reused. When you shift into reverse it moves pretty normal but when you shift into Drive it doesn't wanna move at all and if you put it down into 1,2,3 it will go forward when you get to about 2000 rpms... I need to finish this truck soon and I don't know any one that has the knowledge and time to come help me out, any input would be greatly appreciated. I don't know if its the converter but I hope it is, aside from getting a pressure guage and checking things out I'm stuck. Please help?!?!?!?
Thank you in advance.

[rick 427]

It's not the converter,as it backs up ok. It would also take 2000 rpm's to back up if the converter was bad.And it is also not a pressure or low fluid problem,again,as reverse is not affected. I don't know exactly what it could be,but if someone else rebuilt the trans, and it came to me,I would take it apart,and look for the cause.

[cobalt327]

Originally Posted by Regular6d

Hey guys I'm working with a 700 R4 in an 83 K10, it was rebuilt a few months ago the original converter was reused. When you shift into reverse it moves pretty normal but when you shift into Drive it doesn't wanna move at all and if you put it down into 1,2,3 it will go forward when you get to about 2000 rpms... I need to finish this truck soon and I don't know any one that has the knowledge and time to come help me out, any input would be greatly appreciated. I don't know if its the converter but I hope it is, aside from getting a pressure guage and checking things out I'm stuck. Please help?!?!?!?
Thank you in advance.

Start by setting up the TV cable linkage correctly- it has to be set right or the tranny will fail!

[Regular6d]

Well we have set up the tv cable properly now, and pulled the trans apart again, there were two bent friction plates in the 3-4 set and other than that everything else seemed normal. I was told the front pump was replaced during the rebuild, and we now have a known good torque converter, problem still persists tho. Would the front pump make a difference? By that I mean if my trans has no aux valve body and the pump came off of one that did could the hole where the crossover tube goes be causing the problem? I was reading the Haynes trans book and it mentions plugging the hole if it wasn't could that cause the issue like theres not enough pressure being built up?

[cobalt327]

Originally Posted by Regular6d

Well we have set up the tv cable properly now, and pulled the trans apart again, there were two bent friction plates in the 3-4 set and other than that everything else seemed normal. I was told the front pump was replaced during the rebuild, and we now have a known good torque converter, problem still persists tho. Would the front pump make a difference? By that I mean if my trans has no aux valve body and the pump came off of one that did could the hole where the crossover tube goes be causing the problem? I was reading the Haynes trans book and it mentions plugging the hole if it wasn't could that cause the issue like theres not enough pressure being built up?

First, I am not a TH700R4 transmission expert. But there seems to me to be a mismatch between your pumps, just as you suspect. Besides the obvious problem of a potential pressure loss due to an unplugged port, there is also a difference in the later pumps as to being pulse with modulated or not. How that might affect the tranny lock up function of the TC I cannot say, just something you might want to look into.

But either way, I would want to know what the pressures are. A gauge can be made fairly cheaply- 700r4 slipping

[Regular6d]

Originally Posted by cobalt327

First, I am not a TH700R4 transmission expert. But there seems to me to be a mismatch between your pumps, just as you suspect. Besides the obvious problem of a potential pressure loss due to an unplugged port, there is also a difference in the later pumps as to being pulse with modulated or not. How that might affect the tranny lock up function of the TC I cannot say, just something you might want to look into.

But either way, I would want to know what the pressures are. A gauge can be made fairly cheaply- 700r4 slipping

Thanks Cobalt I am going to get a pressure gauge today I'm sure I can make one. I will probably not get to working on the truck till tomorrow but I will post my results thanks again for all the responses.

[Regular6d]

So I finally got the transmission figured out and I'm still having the same issue. Only thing I an figuee now is that the timing is incorrect. I have it set at 8 btdc and it idles fine but it has to be at around 26 btdc to get into gear without dying, I havw no clue what cam is in the motor so I am not sure what the baseline timing should be, I do know its not a stock cam but I didn't install it so don't have any info about it. Any thoughts about course of action would be great. Thanks all