transmission 1st & 2nd no 3rd or O/D

[grandprix2+2]

Okay, so I'm pretty scared right now. Just coming home from work, I'm on the highway and go to pass a car that is merging, put it to the floor maybe halfway - 3/4. transmission shifts down, revs up, and wont go back into O/D when i let off, Then shifts down to second. (slipping like crazy now) My exit wasnt far so I let her slow down a little and got off. 2 mins from the exit to my house and it shifts into second fine then thats it.
86 Grand Prix w/ 350 290hp 325tq
700R4
Kickdown cable was set up professionally by a local speed shop.
Am I screwed or do I have a chance that somehow a line broke or a vacuum came off? Fluid seems to be where it should be and does not smell burnt. Reverse still works as well.

 

[TURNA]

check the cable b4 anything

 

[79GP6.6L]

I had a 700R4 with a shift kit and billet servos in one of my cars. It shifted HARD. One night it did something similar to what you described. The next day it was fine. I took down the pan and discovered that one of the valve body bolts had worked its way loose, perhaps because it always shifted so hard. I'm not saying thats what your problem is, but thats what your story reminded me of.

700R4's don't use a vacuum modulator, just the TV cable and the converter lockup harness on the side.

Are you sure then shifter was in gear, and not out of position (like in between gears)?

 

[grandprix2+2]

The transmission doesn't have a shift kit in it but I do let'er have all shes got on a regular basis. The TV cable was set back in april and the car has been a blast since, up untill yesterday. Nothings been monkey'd with since. Is it common for a TV cable to have to be re-callibrated when it has been working consistantly? It just seems strange to me but I'm liking the idea of that being it. A friend and I had tried to set the cable ourselves in the past with little success. (hence the speed shop doing it) But that was before I found this forum. I have been searching and I feel bad for asking, but where can I find a link for a detailed set of instructions of how to set that darned thing(mabe even pics?). Is their any way to tell if its set properly Before I try messing with it? I'm going to take her for a quick spin to see if mabe lady luck finds me after reading your post 79GP. Thanks for the info and yes the shifter was in gear I tried it in every position and still couldn't get it past 2nd.

 

[megaladon6]

check your fluid

 

[grandprix2+2]

Fluid is where it should be and smells alright. I'm tempted to goto a transmission shop and see if they can figure it out.....but I don't want a large bill. I have a 200R4 that was in the car before the 700R4, it was just going through fluid.(uncle blew the original transmission years ago, he got this one out of a totaled car with very low miles. im thinking it must have a crack in the case, he put alot of money in it but it always went through fluid.) I got this 700R cheap and was convinced it was far superior to the 200R and thats why its in the car.(also before I found this forum) I'm thinking probably my easiest/cheapest bet might be to put the 200R in until I can find the funds to rebuild onw. (the 200R had 4 gears when i pulled it out anyway :lol: )
Slap me fore being stupid, but I think the 200R uses a different kickdown cable than the 700R, correct? Just curious cause I thought I left the old cable with the old transmission but I didn't see it tonight, I'll check again tommorow.

 

[3rdgentug]

this could be many things
1st off are you sure its 1st and 2nd you have and not 1st and 3rd?
or 2nd and 4th?

have you let it cool all the way down and tried to drive it since?

 

[79GP6.6L]

TV cable adjustment: http://www.thirdgen.org/detent

A transmission shop might not be able to tell you much if they can't duplicate the problem. Have you had any more problems with it, or is it working fine now?

Here's a better one: http://www.tciauto.com/Products/Instructions/instructions/gm_tv_cable_adjust.htm

 

[grandprix2+2]

Thanks a million 79GP! That second one actually makes it seem quite simple.
I let the car sit for a day before trying it again and the problem persists. It is definitely 1st and 2nd that I have because it will start to rev before it would even get to 50 cruising. I know exactly when it usually shifts since its my daily driver and it won't come out of second no matter what i do to it. Someone suggested to have a look at the linkage and see if that has become loose.... :?: I'm lucky that there is currently an extra car in the driveway so I've been using it these last 2 days.

 

[grandprix2+2]

Re-adjusted the tv cable with no success in solving my problem. I even disconnected it all together, still same behavior. It will rev till about 3000rpm in second gear, (around 60kmph) then stops pulling and starts slipping like theirs no tomorrow. Could the modulator possibly have a roll in this? If so how can I test it? :?: