Transmissions and DrivetrainNeed help with your trans? Problems with your axle?
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
is there a way to make my tranny shift sooner?
with my tpi on a 350, it get up to about 4800 rpms, then takes forever to get the last 500 or so rpms before it shifts and takes off again in the next gear.
its kinda against what everyone normally wants to do for a "performance" modification, but i think that if i could get it to shift at around 4800 at WOT then i would actually be quicker than dragging it out to redline
anybody got any ideas?
i know that if i got a constant pressure valvebody then the TV cable could be loosened up to lower the shift points, but is there another way to do it?
i would rather not have to have someone tear apart the transmission again unless it needs it.
It's easy, you just adjust the detent cable. I did it on mine. Only problem is that it will shift sooner all the time, not just when you are at WOT. The cable goes from the trans to the throttle body. Then you depress the throttle it pulls the cable and tells the trans how to shift based on how hard the throttle is being pressed. To adjust it you press the button on the end of the cable and hold the throttle wide open. In your case you won't go to quite WOT before you let the button go. It may take a few times of doing it to get it where you want but it has worked great for me. It shifts right before it falls on it's face and pulls through every gear.
the problem with that is that, especially if you have a beefed up motor, the trans will not apply full line pressure and burn itself up.
thanks, but that seems like a bad idea to me
the governor springs need to be changed. Buy B&M governor kit that comes with different springs and weights. Retail is about $35. Or you could weld a little weight on your original weights and grind it off a little at a time until you get it correct.
the problem with that is that, especially if you have a beefed up motor, the trans will not apply full line pressure and burn itself up.
thanks, but that seems like a bad idea to me
Did not know that. I did not realize the cable directly effected the line pressure.
Did not know that. I did not realize the cable directly effected the line pressure.
Phil
PROPER TV CABLE ADJUSTMENT IS ESSENTIAL TO THE LIFE OF A 700r4 or even 200r4 for that matter. Adjust it properly or you will smoke the clutches. A TBI Truck governor will give you 4,500 rpm WOT upshifts.
is this something you can easily swap out or do you need to completely disassemble and re assemble the trans
If the detent cable was not meant to be adjusted, they would have made it non-adjustable from the factory. Just depress the button behind the bracket and bring the detent cable's housing down one click toward the throttle body. This will allow you to shift a tad sooner....
If the detent cable was not meant to be adjusted, they would have made it non-adjustable from the factory. Just depress the button behind the bracket and bring the detent cable's housing down one click toward the throttle body. This will allow you to shift a tad sooner....
This is exactly what I said to do in my post and I got slaped on the hand for saying it. I currently have mine so it shifts in the 4300-4400 range and it shifts good and stiff like it should. Not sure what to think now.
the reason it is adjustable is to make up for any slack in the cable or differences in cable lengths or stretch over time.
its general good practice to make wearing components adjustable.
i still wouldnt feel safe having it looser than it is supposed to be.
what that is essentially telling the transmission is that the throttle is not pressed down as far as it really is.
there may be some room for error, but i wouldnt do it that way.
the reason it is adjustable is to make up for any slack in the cable or differences in cable lengths or stretch over time....
No. The adjuster is there to tailor the shift points, not to make up for any slack. The only way you'll burn up the transmission is if you delay the shifts for an extended period of time, as that is the only way to cause wear and tear. Shifting early allows for the tranny to live longer. All the cable does is control line pressure, that's it. When the housing is further out, shifts occur too early. When the housing is further in, shifting occurs much later. Nobody runs the detent cable all the way out, or all the way in, it's design is to find a happy medium in between....
I would think that by pulling the cable sooner it would add more line pressure and if that's correct I have never heard of a transmission going bad because of too much line pressure.
I would think that by pulling the cable sooner it would add more line pressure and if that's correct I have never heard of a transmission going bad because of too much line pressure....
Pulling the cable sooner would mean to set the cable's housing (sliding mechanism) closer toward the firewall. The volume of the fluid is designed to increase as torque increases in a linear fashion, not all at once. Too much pressure allows for unnecessary stress on a transmission that is not designed to take it from the factory. Shifting obviously allows for the decrease in RPM, and the stress that is associated with it. This is why a happy medium is needed. Nobody is saying you can't add line pressure for firmer and extended shifts, just understand that your obviously abusing the transmission more than if you weren't....
but if you have less pressure, there is less force on the clutches.
you wouldnt drive down the road with your foot on the clutch pressing it down half an inch would you?
the clutches in an automatic are just like a manual clutch.
it only wears when its in between on or off.
if its on, its on, if its off its off.
when its slipping is when you have problems.
true there is more "shock" when it shifts later, but even if you had it pulled all the way tight and it had to rev up to redline to shift in daily traffic, it still wouldnt come close to when you floor it in first gear and hook for real.
all i am saying is that the TV cable is supposed to be adjusted a certain way.
you can go tighter without any real consequences as long as it is in good shape, but i wouldnt dare loosen it up.
think about it for a second.
you are telling the trans that you arent giving it as much gas as you really are.
this cant be good
personally, id love a 6L80E and be able to tune each shift point electronically, but since i am stuck with a 700r4, ill just do the governer thing
but if you have less pressure, there is less force on the clutches. you wouldnt drive down the road with your foot on the clutch pressing it down half an inch would you?
But that is completely irrelevant though. You initially asked how to lower your shift point, and I told you to lower your line pressure by bringing the adjuster one click toward the throttle body. That will in no way hurt your transmission. Doing this lessens but a fraction of the applied force that is entering the feed orifice. Trying to associate what I'm saying with a half applied manual clutch pedal has absolutely nothing to do with what I'm talking about, because I'm not telling you to lower pressure to it's most least point. Again, it's about finding a happy medium....
Quote:
Originally Posted by RED_DRAGON_85
the clutches in an automatic are just like a manual clutch. it only wears when its in between on or off. if its on, its on, if its off its off. when its slipping is when you have problems. true there is more "shock" when it shifts later, but even if you had it pulled all the way tight and it had to rev up to redline to shift in daily traffic, it still wouldnt come close to when you floor it in first gear and hook for real.
Again, this has nothing to do with what I'm saying. There are two ways to damage a transmission, excessive heat, and excessive force; too little line pressure, and too much line pressure. That being said, what you wrote above has nothing to do with finding a happy medium with the detent cable, because a happy medium will avoid both instances. Lowering your line pressure one click is not a cause for panic, it will simply do what you initially asked....
Quote:
Originally Posted by RED_DRAGON_85
all i am saying is that the TV cable is supposed to be adjusted a certain way....
You are not thinking too clearly. If you try and adjust a worn TV cable the "GM" way, it will not ratchet into place. This is why the detent cable is adjustable in the first place, it allows you to set it where it needs to be if it does not do it on its own. You honestly think I couldn't set my detent cable free handedly in the same exact place that the "GM" way would have ratcheted into on it's own lol? It's not magic my friend, it's the simple placement of a setting....
Quote:
Originally Posted by RED_DRAGON_85
you can go tighter without any real consequences as long as it is in good shape, but i wouldnt dare loosen it up. think about it for a second. you are telling the trans that you arent giving it as much gas as you really are. this cant be good
.... you wouldn't dare loosen it up one click lol? Oh my goodness, your giving the simple and primitive method of the tv detent cable way too much credit here lol.
Quote:
Originally Posted by RED_DRAGON_85
personally, id love a 6L80E and be able to tune each shift point electronically, but since i am stuck with a 700r4, ill just do the governer thing....
You'll just do the governor "thing" lol? Okay, you just do that, but you'll have to reset your detent cable all over again anyway, and it's going to be a complete waste of time if the cable doesn't self-align for you because you'll be in the exact same boat all over again from which you started, albeit with a new governor....
Good luck....
Last edited by Street Lethal; 05-07-2009 at 11:52 PM.
I will probabaly just leave it the way I have it set. If it really does cause a problem having it adjusted "incorrectly" I will buy anothe $200 700R4 and replace it.
Phil
__________________ 1989 Pontiac Trans Am GTA
Almost Stock.
Last edited by Samdweezel05; 05-08-2009 at 06:37 PM.
well see when i had mine rebuilt, the idiot that did it (literally the dumbest guy on the face of the planet) thought it would be a good idea to make the trans such that it wont shift out of first gear until 2500 rpms... ive taken it other places and apparently he "modified" the valvebody...
whatever.
but he also made it so that it needs to go to over 5500 before it will shift at WOT, (i just checked a few times today and it definitely goes up to about 5600 or so, waits, then shifts, and i get to accelerate again.
street lethal
wow, you had to break out the multiquote on that one...
good job.
basically you seem to be pissed that im not going to disregard everything that everyone has ever told me before and listen to you...
its ok.
im not trying to insult you or anything, but to ME, it seems like a stupid idea to trick the transmission into shifting earlier, especially with a well built 350 TPI that can break the tires going into second...
if it works for you, great, im happy for you... im just not going to do it myself.
No. The adjuster is there to tailor the shift points, not to make up for any slack. The only way you'll burn up the transmission is if you delay the shifts for an extended period of time, as that is the only way to cause wear and tear. Shifting early allows for the tranny to live longer. All the cable does is control line pressure, that's it. When the housing is further out, shifts occur too early. When the housing is further in, shifting occurs much later. Nobody runs the detent cable all the way out, or all the way in, it's design is to find a happy medium in between....
Its NOT THERE TO ADJUST SHIFT POINTS, PERIOD, END OF STORY!!!! YOU WILL FRY THE CLUTCH PACKS IF THE TV CABLE IS NOT SET CORRECTLY!!!!!!! I CANNOT STRESS THIS ENOUGH. I BUILD THESE TRANSMISSIONS ALL THE TIME AND KNOW HOW THEY WORK.
I am not the only one stressing this as it is the TRUTH.
