I read on the lock up switch in the tech section of this board and it said that using the switch is hard on your trans?? I wanted to use the overdrive as it was intended at speeds above 45mph will this hurt the trans??? I have a 87 gta that I bought as a rolling chassie and I have a carbed 350/700r4 combo now I know that with out the computer the trans wont shift into overdrive but will that switch mod work in my car??? also the tv cable hooks to the carb do they adjust the same way???

 

I had to buy a throttle cable mount from Mr Gasket I believe. I thin had to modify it to use the exsisting throttle and tranny cables. Works fine.

As for the lock up swith check out this thread.

https://www.thirdgen.org/techbb2/sho...hreadid=230910


You want to have the lock up for mileage reasons and I read once in HR or CC, that it is possible that you can overheat your tranny in OD with no lock up. It never happened to me but, I like having the lock up feature and don't want to take any chances.

 

the Question that i have is if I dont use the lock up will that fry the trans????? I found some info on this much but not alot HELP almost ready to drop in motor and trans

 

The computer doesn't control the shifting of the transmission. It will shift into overdrive, and all the other gears, just fine.

Without the TCC locking, you'll lose a little mileage on the highway, and your transmission will run hotter. How much hotter depends partly on how your cruising speed relates to the stall speed of your converter.

 

This is the point that the magazine artical was trying to make. They stated that if you had a 3:73 gear or lower, that it shouldn't be an issue. But if you had a 3:23 or a 2:73 your TC would be at stall speed during most of your cruising because of the slower tranny RPM vs. higher engine speed.

But that was all based on a stock TC in a 700R4.

They made it sound like you'd burn up your tranny in one day. But I didn't read the article till after I had run my Caprice all summer long with the lockup dissabled. I then hooked it back up and never had a problem. The car was an 84, it weighed 3900+ pounds, I installed a shift kit, it had a 2:73 gear, and I put around 5,000 miles on it that summer with no lock up.

 

Cruising in O/D below the converter's stall speed with the TCC unlocked produces the most heat due to the shearing in the fluid in the converter, at the same time as the pump is turning at its slowest causing minimal flow through the cooler. If you have a transmission temperature gauge, you can plainly see the increase in temperature.

 

If he was to install a shift kit that raises the line PSI the pump puts out, would this help out in the movement of fluid to the cooler?

I dunno,... I would just hook up the TC and be done with it. Its not that complicated, and it will be easier on the wallet both in fuel costs, and possible damage from over heated fluid.

 

I have found out alot of info on this subject now I guess I was looking in the wrong places before as I understand I need to drop the pan and re-wire the 4th gear N/O pressure switch with the ground from the lock up solenoid (just like the kit you can buy from painless) then 12v power is supplied when the car is on so basicly the way I understand this when the trans shifts into 4th the switch closes and completes the ground to the solenoid and the converter will lock. Now I klnow with the painless kit they give you a new brake switch and a vaccume switch I am not sure why they are using that in their kit the instruction can be found on the summit site the painless part #60109 I have the instructions but they are in a pdf file wont let me up load if you want I can send them to you

 

The vacuum switch is to unlock the TCC at WOT and when coasting. The brake switch, as I understand it, is to prevent stalling the engine in a panic stop.

 

well I have I feel all the info that I need to do this swap! I all so have the Gm part number for the stock vacuum cancle switch and the number for the N/o forth gear pressure switch I might post all of my findings in a tech article so that eveyone can have this infomation in one spot instead of going all over the web like I did to find it

 

please post were all the information is I am going through the same procedure and this would help alot.

 

https://www.thirdgen.org/techbb2/sho...hreadid=230910

I started doing a tech article on it quite a while ago, just haven't got around to tearing a transmission apart to take pictures.

 

I have the pictures maybe we can work on it together????

 

Sure, works for me.