Recently picked up a 68 Belvedere with a 318 and it runs great except one thing, every time I hit 25 - 30 mph in D it kicks down into passing gear. I have tried adjusting the kickdown linkage using the open throttle method and there was no real change. After I made the adjustment, it did shift into third but only at 50 mph and with the throttle wide open. As soon as I let off of it, she kicked back down into passing gear. The shift linkage in the column is a little loose, but D2, D1, and R work just fine. It shifts smoothly from first to second, but as soon as I hit what should be third it slips into passing gear. At this point I am open to any advice. I thought that maybe investing in a Lokar cable may fix it, but I don't know at this point.

 

Did the return spring fall off the linkage????Bill

 

I Agree... ???

 

The spring was originally on completely backwards and I thought that was the issue, but after fixing and adjusting the linkage, I am still having the issue. I just did a test with the linkage tied all the way forward so that the kickdown couldn't trigger and it still just shifted right back to first at about 25 mph.

 

Has it ever been right? Maybe the last guy put a crazy shift kit in it?

 

No not since I got it. The guy I got it from said it would be an easy adjustment on the kickdown linkage and from what I first experienced when I test drove it, I thought he was right. After I adjusted the linkage, there was no real change. Maybe I still haven't adjusted it properly? There is supposed to be a special tool you use when doing it, but no one I know has it, so I used the alternate open throttle method.

 

Next step is the Valve Body needs to come out and be cleaned...It sounds like the kick down valve is stuck...You could just get a new valve body and eliminate the problem all together...Bill

 

Well that's actually good news if that's really what it the issue is. Do you think a transmission flush would take care of it? I've never been inside a transmission and I'm not exactly excited to give it a try right now.

 

There is an adjustment inside for the throttle valve. Maybe previous owner was in there.

 

Something is wrong With it tied all the way forward ? You would not have any throttle post Picture see if we can figure it out

 

For the kickdown linkage at the tranny, should there be any resistance when it is pushed back? Mine has no resistance and I was told that it should.

 

Very little like pushing against a spring

 

It sounds like it might be unhooked inside the transmission or it is broken....Bill

 

Ok thanks, we are going to check the valve body this saturday. The weather is suppose to be crap until then.