TV cable adjustment.

[SS_Sean]

I'm thinking now that I've done spring cleaning, and have replaced a worn rocker shaft assembly that finally broke, and have replaced all the vacuum lines, my turbo is spooling like crazy fast! In fact, I believe I'm hitting the rev limiter before the car can make a 1-2 shift.

Question is, how do I adjust the tv cable so that the tranny shifts 1-2 sooner, prior to 6000 rpms?

 

[RUQWKNF]

Here is a quick link that I found with basic information.

GM TV Cable Adjustment Instructions

It could be that your cable is set too tight and the pressure is so high that it won't allow the trans to shift. I have seen this happen before on cars that have the original TV cable or one that had been stretched. It's best to replace this cable with a new GM piece if the car has high mileage. I'm sure there are past posts about properly setting it on a Buick on here as well. I've always had the best luck with having the plastic slider indicator sticking out about 1/4" from the adjustment button assembly. Make sure that the throttle can go WOT after you set it.
HTH

Patrick

 

[scottyb]

FWIW, I've always had to manually adjust mine after the "procedure", especially after installing the shift kit. I had to move the cable "cover" forward quite a bit because it waited FAR too long to shift.

 

[SS_Sean]

Thanks, guys. I have the shift kit installed, and obviously my shift points aren't the same anymore. I'll adjust manually and play with it until I get it right.

 

[Blazer406]

IMHO, there is only one "correct" way to set it. Any other way compromises the pressures intended for the clutches....

Depress the tab... push slider all the way in toward the firewall....then release tab.... then by hand... rotate throttle until wide open (engine off of course) This will rachet the adjuster mechanism out making WOT... full extension of the TV cable..... any adjustment to manually move the slider any further out.... will result in WOT not being a full extension of the TV valve... therefore compromising (to some extent) the hydraulic pressures holding the clutches.

The shift points ....... if they don't suit you.... should be altered elsewhere in the tranny (governer weights.. etc.).

 

[scottyb]

IMHO, there is only one "correct" way to set it. Any other way compromises the pressures intended for the clutches....

Depress the tab... push slider all the way in toward the firewall....then release tab.... then by hand... rotate throttle until wide open (engine off of course) This will rachet the adjuster mechanism out making WOT... full extension of the TV cable..... any adjustment to manually move the slider any further out.... will result in WOT not being a full extension of the TV valve... therefore compromising (to some extent) the hydraulic pressures holding the clutches.

The shift points ....... if they don't suit you.... should be altered elsewhere in the tranny (governer weights.. etc.).

I may be wrong, but when I had the same issue (and posted the same question here) replies stated that TV cable adjustment had nothing to do with WOT shifting and pressures. TV adjustment is for part throttle shifting.

I don't know the true age of my transmission (bought the car with 150k miles). I now have 225k miles, and 50k of those are with the shift kit and the TV cable manually adjusted as I mentioned.

 

[BlackBandit]

I may be wrong, but when I had the same issue (and posted the same question here) replies stated that TV cable adjustment had nothing to do with WOT shifting and pressures. TV adjustment is for part throttle shifting.

I don't know if that's true or not and I'm definitely not a tranny expert. It seems to me though that the tv adjusts shift firmness and shift points via hydraulic pressure changes, and the tv cable is the only way the tranny would know if you were at WOT. I think the governor sets WOT shift points but if the tv cable is too loose I think you'll end up with a bunch of smoked clutches. Could be wrong though. Maybe one of the tranny guys will let us know.

 

[SS_Sean]

Well, at this point I can't get a 1-2 shift without bouncing off the rev limiter, so any help is appreciated!

 

[Lee Thompson]

cable adj.

Set per instructions--if shifting to late--move slider toward front of car 2-3 notches--if this makes no difference--you will have to go inside trans. Any thing over 2 clicks worries me about dropping line pressure TOO much. A pressure gage would be of great benefit. With a gage on mine and while driving--any throttle angle over 1/2 throttle raises line pressure to MAX. Best of luck.

 

[brian]

Well, at this point I can't get a 1-2 shift without bouncing off the rev limiter, so any help is appreciated!

Kind of sounds that withy your new found power, you are driving over the band/clutches. Is is a situation where if you lightly lift off the accelerator it will shift?
What was/is the condition of the trans? Did you install a Transgo kit?
OR, you may have a mismatched governor and v-b.

Brian

 

[SS_Sean]

Unfortunately the tranny is a mystery tranny. Well, actually, the car has been a mystery car. I bought it about a year ago, and I've spent the last year fixing all the okie sh!t done to it. I'll try moving forward 2-3 clicks and see what happens. Lifting slightly isn't an option. I do run the car at the track occasionally. :wink: :biggrin:

 

[Blazer406]

Brian... or Lee.....

Can you tranny guys enhance/confirm/deny what I posted..... seems there is a fair amount of mis-information... that you can just move that slider wherever... to make the shifts do whatever you want them to.....

IMHO... this is a bad idea.... however I don't think 1-2 clicks is way out of adjustment either.

I also agree with Brian... about overpowering the clutches... and the trans not wanting to shift.... been there and done that with a 700R4 behind a built small block Chevy.

 

[BlackBandit]

Lifting slightly isn't an option. I do run the car at the track occasionally. :wink: :biggrin:

I think Brian was asking this to help diagnose your problem, not to suggest that's how you should drive your car.

 

[Lee Thompson]

With my limited experience

Brian... or Lee.....

Can you tranny guys enhance/confirm/deny what I posted..... seems there is a fair amount of mis-information... that you can just move that slider wherever... to make the shifts do whatever you want them to.....

IMHO... this is a bad idea.... however I don't think 1-2 clicks is way out of adjustment either.

I also agree with Brian... about overpowering the clutches... and the trans not wanting to shift.... been there and done that with a 700R4 behind a built small block Chevy.

More power (torque) will raise the shift points (boost increase or just more horesepower @ the same boost).
I believe in a gage. Try turning the boost WAY down.

 

[SS_Sean]

The boost is set at 15 psi. Why would I turn the boost down. The combination is in the signature, is very mild, and surely people of been through this before??

 

[Blazer406]

The boost is set at 15 psi. Why would I turn the boost down. The combination is in the signature, is very mild, and surely people of been through this before??

More than likely... you are staring at a tranny rebuild. Like Brian said... it is probably overpowering the clutches... that is why it won't shift. He suggested trying to see if you lifted the throttle just slightly... if it would shift.... If you lower the boost a little... and it shifts at WOT.... then the power level you are at is likely exceeding the holding capacity of your clutches for one reason or another.

 

[SS_Sean]

Ah, I see....isn't that special.

 

[brian]

Brian... or Lee.....

Can you tranny guys enhance/confirm/deny what I posted..... seems there is a fair amount of mis-information... that you can just move that slider wherever... to make the shifts do whatever you want them to.....

IMHO... this is a bad idea.... however I don't think 1-2 clicks is way out of adjustment either.

I also agree with Brian... about overpowering the clutches... and the trans not wanting to shift.... been there and done that with a 700R4 behind a built small block Chevy.

Blazer,
There is definatly a limit to every adjustment you do.
More than 1 click under the necessary minimum (factory preset in my eyes), the trans MAY never shift, and you will have a flair. In a healthy trans you can manipulate the cable to taylor the shift you want, to a point. (I say 1 click either way) If you have a billet 65-70mm T-B, you get into a whole other issue.
Back in the early days, guys would go to the dragstrip and raise their TV settings 1-2 clicks to try and get more rpm out of the trans, and they would be "hangy" at part throttle cruise.
As Lee pointed out, a gauge is the best tool for diagnosis. And overall torque can raise the shift points afew hundred anyways. In a Chevy, a trans that shifts at 5000 can shift at 55-5600 in a TR.

Sounds like our thread starter here has possibly more of an issue now that his car is in a proper state of tune.

 

[SS_Sean]

Proper state of tune just went out the window. I had to put the tv cable back to original setting as I may have a problem with the motor going on now...big problem. Will post in another thread and try to come back to this issue when the car will actually run under boost!!