Found Disconnected Linkage, What is it?? Transmission, 67 Newport w/ 383

[OneEyed]

I was looking through the engine compartment and saw something like a tube or metal rod just hanging around, going nowhere. I laid down under the driver side door and reached up in there and found that its some sort of linkage from or to the transmission. I found where it was supposed to attach and after some messing around, it snapped back into place. I'm not sure how long this has been detached or what it even does. I cannot physically get underneath the car at all to really get a good look, so I took a pic. The X is where it was disconnected.

 

[-stew-]

That's the kickdown rod. Pretty important.

 

[OneEyed]

So what does it do? I've been driving it recently...so is it possible to drive with it detached or did it just happen to do it as I pulled it into the garage tonight?

 

[Wollfen]

The kickdown operates when you are driving along and you accelerate moderately to hard, it then switches you down a gear for faster acceleration. Without it connected you would simply accelerate slower in the gear you are in.

 

[OneEyed]

Oh okay, thanks for the info! I've only been driving it to and from work recently about 30 mph tops, so I probably wouldn't have noticed I guess.

 

[tallhair]

It would run just fine w/o it and you can manually shift down to second. But that's not as intended nor ideal for full enjoyment.

However whats going on is: A slotted rod connected to the carb throttle lever, which is then connected to another hinged/elbow rod that goes down behind the head on the drivers side down to that piece which is connected the trans kick down lever. When you are cruising along and kick the throttle back enough the kickdown linkage downshifts the trans to second gear.

Here's a diagram for a small block but same idea

 

[polara71]

Aka....passing gear

 

[commando1]

Anybody else want to chime in about the Transmission Kick Down And Passing Gear Linkage?

 

[polara71]

Nope.........

 

[bulldogchesty]

Anybody else want to chime in about the Transmission Kick Down And Passing Gear Linkage?

Wow, someone has a case of the Mondays. Luv ya man.

 

[MrMoparCHP]

I'm no mechanic but there is far more to this than a passing gear.
Running without it is a bad thing, it takes throttle feedback mixed with pressure to hold the shifts.
Again I do not know the details but I have been told multiple times that it is very important to have hooked up and adjusted.

Hard shift one way late shift the other.


Alan

 

[-stew-]

I'm no mechanic but there is far more to this than a passing gear.
Running without it is a bad thing, it takes throttle feedback mixed with pressure to hold the shifts.
Again I do not know the details but I have been told multiple times that it is very important to have hooked up and adjusted.

Hard shift one way late shift the other.


Alan

Without it my 79 PowerWagon would be in third gear before you made it through the crosswalk.

 

[commando1]

Wow, someone has a case of the Mondays. Luv ya man.

Not really. I thought it was kinda funny...

 

[Catfish]

I'm no mechanic but there is far more to this than a passing gear.
Running without it is a bad thing, it takes throttle feedback mixed with pressure to hold the shifts.
Again I do not know the details but I have been told multiple times that it is very important to have hooked up and adjusted.

Hard shift one way late shift the other.


Alan

Ive heard it's important too. When I had transmissions built for a specialty application that didn't use the kick down, nor were they built with a manual valve body, the builder did some internal mods and removed the kick down lever.

 

[bulldogchesty]

Not really. I thought it was kinda funny...

I hear ya. Remember my post with just an i?

 

[Big_John]

I'm no mechanic but there is far more to this than a passing gear.
Running without it is a bad thing, it takes throttle feedback mixed with pressure to hold the shifts.
Again I do not know the details but I have been told multiple times that it is very important to have hooked up and adjusted.

Hard shift one way late shift the other.


Alan

This is correct. It really isn't a "kickdown" linkage. Simplified, it modulates the line pressure that applies the bands and clutches. It works against the governor pressure and when the governor pressure exceeds the throttle pressure, the valves in the valve body shift and apply pressure to the bands and clutches to apply/release as needed and the trans shifts. More throttle... more pressure....

Without it, the line pressure needed to apply the bands and clutches is low and there isn't enough pressure to properly apply them. It'll shift early, but that isn't the real issue. Without the proper line pressure, figure on the band and clutch life taking a nose dive.

So, yes... It's very important and it's a lot more than making the car downshift. Let unhooked, expect cooked bands and clutches in a very short time.

 

[OneEyed]

Thanks for all the great responces!! Now I'm wondering how it ever came disconnected, I guess I'll have to keep an eye on it.

 

[polara71]

I learned the hard way. Going from a 318 to a 340 i didnt have the correct linkage. I blew through a few transmissions before someone pointed out why.

 

[66SportFury]

Thanks for all the great responces!! Now I'm wondering how it ever came disconnected, I guess I'll have to keep an eye on it.

There's usually a clip that holds it to the end where it came off. Make sure the adjustment is correct also and lubricate all the connecting points. To adjust it,.. At WOT, adjust the linkage at the carb to push the kickdown lever as far back as it would go. There should be an adjustment near the firewall and at the carb to do this, but make sure you get WOT. If you go to far, it will not let the the carb open all the way.

 

[70bigblockdodge]

Connect it now or a toasted trans you will be eating.