Transmission cable issue

[InVision]

I have a 305 in a 1985 K-10 truck. I have a TH700R4 automatic transmission that has what I call a "Kick down" cable attached to the Quadajet carb. When I put the cable on the carb it is too short to allow full throttle. When I push the button and extend the cable until it allows full throttle, then does not down shift when anymore even with WOT. Kick down cable is slack at idle.

Any ideas???

Thank You,

M

 

[CSFJ]

It's called a throttle valve (TV) cable on the 700r4. There's a couple of threads on here, and plenty of videos on you tube that walk you through it. Extremely important to get that adjusted. Incorrect adjustment will burn the trans out in short order

 

[InVision]

Well I pushed the button and released it, then went to WOT and the cable clicked. That seems to be how to adjust by watch videos. Thanks for telling me what it is called. Learning is good

M

 

[CSFJ]

No problem. Watching a few minutes of video can explain it far better than I could with a couple paragraphs.

 

[InVision]

But it does not downshift set like most videos said to set. Also most vids are Holley carbs with optional linkage...

M

 

[74 Shortbed]

Got a pic??.

 

[InVision]

here a a few. took cruise control off to see linage better.

Thanks,

M

 

[CSFJ]

Is the cable original? When I first brought my '88 home, the hacks who had worked on it previously didn't inspire much confidence so I readjusted it. couldn't get it to really adjust properly , so I made a trip to the dealer, and picked up a new cable for it. That one adjusted as it was supposed to, and I haven't had an issue with it since.

 

[InVision]

Wow I guess I am lost. The cable is loose at idle and can't go any tighter at WOT. How would a different cable change that? I was thinking it was the linkage on carb that could be wrong. The TV cable being further away from pivot point would change indexing.

Thanks for the reply...

M

 

[CSFJ]

if the cable is stretched or damaged it can affect that. Or if it somehow came unhooked from the catch in the trans.

 

[InVision]

Thank you I will check cable connection on trans tomorrow.

Could the valve itself be bad?

M

 

[1987 GMC Jimmy]

I know this is purely anecdotal, but it took me several months to realize that my TV cable was frayed away from the throttle body after it hadn't been doing right so I had to get a new Delco cable.

 

[74 Shortbed]

Don't look like the cable is in the right spot on the carb????..

Never mind, guess it is in the right spot.

 

[1987 GMC Jimmy]

The cable looks tired to me, like @CSFJ said. I wouldn't suspect valve body problems unless you had more major problems with it shifting, which could then be a number of potential problems. I would just get another cable and try it out. Even if something happens to the transmission soon after, the cable is almost certainly reusable. Make sure you get the TV cable grommet to seal between the plastic cable sheath where the bolt goes through and the transmission housing. I forgot and had to that job twice after the murderous amount of trans fluid that leaked. What a bitch. I learned the hard way that you gotta lop the whole assembly over the transmission so both ends of it are down there with you and pull tension on the cable part so the two fishhooks don't fall apart while you bolt the sheath down back down. After you get that done, you're home free.

 

[InVision]

So I read the service manual I found on this site. Great Job BTW!!

The TV cable operates very smoothly and does not bind or stick. So I adjusted the cable so that idle position is where the TV cable starts and pulls back to on its own and at WOT is the max position it extends. At WOT it is tight like a string instrument.

Will test this evening if I can.

Learning a bunch working on this ol' truck !!

Thanks