DanielRicany

Hey guys, I have a 1985 Corvette with a 4+3. I was wondering how I would go about disabling the kickdown function of the overdrive? I have 3.75s in the rear so if I stomp on it in overdrive I don't want it kicking down and blowing the motor because it thought I still had 3.08s.

I know I'm not supposed to go WOT in overdrive but I need to to get down the track. Have later plans for a ZF6 swap anyway.

Thanks!

hooked073

just picking I saw you a few nights ago holding at 4000 with no load and you said you did not care if it blew now your worried about it

Rohn

I dont quite understand. If not in OD it wont kickdown. I am never in OD cept when I need to use the 5th gear. anAyway I depress chutch and hit button and go to OD/5th. When I go back to 4th I do same. Then I floor it or shift to 3rd and floor it. 3.07 gears.

DanielRicany

I am talking about when I am driving in overdrive and I floor the gas, then it drops out of overdrive. I don't want it to do that I want it to stay in overdrive.

Rohn

Understood. It is just that that practice will take it toll on the OD unit. I believe that is widely believed.

vetteoz

Try adjusting (or disconnecting ) the TV cable at the TB

http://forums.corvetteforum.com/c4-t...-4-3-84-a.html

http://forums.corvetteforum.com/1582048095-post7.html

DanielRicany

That's strange because I let my dad drive my car and I put it in overdrive for him, when we came to a low speed he was in second gear and overdrive and punched it and overdrive kicked down to second gear direct.

This all happened with the TV cable disconnected. I talked to my dad's friend about this when he noticed my tv cable was hanging off to the side. He said I'm going to blow the overdrive unit with that disconnected, said it was for throttle valve pressure, to adjust the pressure depending on throttle or something.

So I'm not convinced that that cable is a kickdown cable.

hooked073

read this Dan the whole thing http://forums.corvetteforum.com/c4-t...djustment.html

vetteoz

On a T700 it does



Other opinions differ

DanielRicany

Its basically saying the same thing that the thread vetteoz posted was saying.

But if that is truly the kick down cable, how come with my kick down cable disconnected, it kicked down when it went WOT?

hooked073

I do not have a 85 service manual look thru yours and read up on it. Like what was in my post is was a 1 year deal with the vettes I have no expericance with them. But the service manual should have a lot

DanielRicany

I don't have one but I think the kickdown may be in the computer?

hooked073

Im going going back to the post I lead you to but if I recall in that post it says 85 is a standlone yr for the 4+3 and after 85 they move the function to the comp. That is why I said read it all

vetteoz

84/85 had the cable.
The shift to the far superior '165 ECM in '86 also bought about ECM controlled kickdown

hooked073

Thanks for clearing that up I spent about a half hr diging up the info for him last night I do not mind trying to help. I said read it all the way thru cause I knew the information he needed was there. I dont have a lot of interest in 85 4+3 and read thru it real fast but say what he was looking for. I felt at this point it was up to him to read in and research more. Dan as you know people on here will help. I did spend a half hr looking for something I had no interrest in. It kinda po me after doing this it did not appear that you read it hard to get the jiff of it.

DanielRicany

I did read it. It was basically saying that the cable is in control of going in and out of overdrive at different throttle positions. But if that's the case, then how could mine shift out of overdrive when I had the cable disconnected when the gas was floored?

vetteoz

Ditto

I spend a lot of time doing research for people with questions because I am as interested in the answers as well as help ;
but when you present the facts you get the " you can lead a horse to water" response
In any case , for the OP's requirements I would run the O/d off a manual switch and delete any ECM / kickdown control

Jojovett

Just bought my first c4 don't nkow much about it yet, you mention that you didn't put you're OD on till your in fifth, mine is a four speed.

Jojovett

My speedo meter not working where is the sender at?

DanielRicany

If your speedometer isn't working, it's possible that your odometer isn't working either and your mileage is inaccurate. The Vehicle Speed Sensor is in the drivers side of the overdrive unit.