Jon89le Posted September 21, 2004 Report Share Posted September 21, 2004 Is there any way to force shift a vacuum shifted transmission like the 4T60? At the track i trap the entire 1/4mi stuck in second gear. It isnt until right past the finish line that it shifts into 3rd. For the last 1/3 of the track she stays pegged right around 6000rpm and ive tryed letting off the gas, getting back on it, to help it shift into 3rd but no luck. Any help? Quote Link to comment Share on other sites More sharing options...
manitcor Posted September 21, 2004 Report Share Posted September 21, 2004 I normally start in 2 and let watch the tach, once it gets to about 5600-5700 I push the shifter into D to give me that last bit in 3rd gear. What are your trap speeds? Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 21, 2004 Author Report Share Posted September 21, 2004 Ive tryed that and it still stays up there like its trying to rev just a bit higher. Im trapping at 79-80mph with a 16.6 ET. Past the 1000ft mark its like the car dies. Quote Link to comment Share on other sites More sharing options...
Smoke1991 Posted September 21, 2004 Report Share Posted September 21, 2004 i actually fool the tranny into shifting into the next gear by letting off the gas and then nailing it again (not wot) because then it would just downshift again. when i start i put it in to 2ed( from a dead stop it starts out in first), and use my foot to fool the tranny into shifting into the next gear by the time i got it in 2ed gear, its about 35 mph and the car wont go back into first again, so i floor it, then right after 4800-5000 rpm, i let off the gas again and nail it again. i got it down to a science, its different with every car, seriously though if your driving next to me from a stop to a go, the way my car changes gear when applying my science it seems like a got a stick in there but yah one day when i get a good vid camera, ill record my foot motions so u get a better idea. also if you dont do it right, example, you let off the gas and right in the middle of the shift you nail it, the car shifts so hard your affraid your w-body car is gona fall apart, or your tranny is going to brake. this doesent apply to me because i got a warranty on my rebuilt tranny, so if i f**k it up, i get it fixed for free. Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 21, 2004 Author Report Share Posted September 21, 2004 WOT situations are different though. I do know what your talking about though. Quote Link to comment Share on other sites More sharing options...
Smoke1991 Posted September 21, 2004 Report Share Posted September 21, 2004 hrmm, then i dont know lol... all im getting is that u want ti to shift and it likes to stay in a gear. im not a tranny smart so i really cant help you in that department. Quote Link to comment Share on other sites More sharing options...
manitcor Posted September 21, 2004 Report Share Posted September 21, 2004 it sounds like your computer might be getting a bad input or something. The PCM checks the Mph first and uses the RPM as a secondary variable when making a shift. But im really not sure. Based on your name you have a 89 LE, I know the t60 farily well but I deal mostly with 1.5 and newer stuff. Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 21, 2004 Report Share Posted September 21, 2004 Whelp, on the 89's there's the manual throtle cable that operates the transmission, you could either adjust that to force the shift at a lower RPM, or disconnect it at the throtle body and attempt to drive it manually, I've heard mixed results from doing that. --Dave. Quote Link to comment Share on other sites More sharing options...
manitcor Posted September 21, 2004 Report Share Posted September 21, 2004 ahh so its not PCM controlled, I zee well in that case shifting manually will work, just keep an eye on the tach and be sure to shift about 200-300rpm BEFORE you want the gear to change as the lag between you moving the shifter and the fluid pressures changing to move the gear will cover that 200-300. Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 21, 2004 Author Report Share Posted September 21, 2004 Whoa, hold on a sec, by cable...do you mean the little TV cable the goes into the top of the tranny pretty much right below the exhaust crossover pipe? And IF that is the cable, you guys mentioned that i could disconnect it and shift manually, is that ok to do? Wont give me any issues with the clutches or valve body? Quote Link to comment Share on other sites More sharing options...
manitcor Posted September 21, 2004 Report Share Posted September 21, 2004 technically no, however I am not familiar with the setup on the older cars the trans should be fine. One reccomendation though, if you are doing hard WOT runs and pushing the RPM as far as you can you really should have a tranny cooler (if you dont have one already) the t60 doesnt like heat. Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 21, 2004 Report Share Posted September 21, 2004 yes, the TV cable, Detent cable, whatever nomanclature you can come up with for it, it all still controls the Throtle Valve in the transmission. Removing it will not make it act like a manual trans car, not by any means - BUT removing it will pull the shift RPM's way down, and allow you more ease of gettin' into your high gear. an OTHER trick you can do, is wire in a manual relay to activate the torque converter clutch, once you hit half track, flip that switch and manually activate it, that will pull your RPM's down some and keep you in your powerband a bit better - you SHOULD see a higher trap speed. --Dave. Quote Link to comment Share on other sites More sharing options...
slick Posted September 21, 2004 Report Share Posted September 21, 2004 an OTHER trick you can do, is wire in a manual relay to activate the torque converter clutch, once you hit half track, flip that switch and manually activate it, that will pull your RPM's down some and keep you in your powerband a bit better - you SHOULD see a higher trap speed. --Dave. Pretty neat idea. Is there any write up on how to do that? Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 21, 2004 Author Report Share Posted September 21, 2004 Ok, so by removing that cable, would i have to shift the car inside the car or is it just lowering the rpm shift? Im also curious for any additional info on that second thing you mentioned. Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 21, 2004 Report Share Posted September 21, 2004 you'll have to shift to a point. if you want to hold some gears out longer in the RPM range, you'll have to manually hold it, but it will allow you to "short-shift" when floored. as for the Manual TCC lockup, I've been meaning to do a writeup on it, I've gotta do a little testing to see how much voltage gets to the trans, but after I get that, I can write it up for ya. I believe it's an honest 12V that gets to it tho, and it provides a ground to operate it. --Dave Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 22, 2004 Author Report Share Posted September 22, 2004 I may try this. Im going to disconnect the cable from the TB and see what happens. Keep us posted on that writeup. Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 24, 2004 Author Report Share Posted September 24, 2004 Another question. Where on the transmission can i adjust the line pressure? If i decrease the pressure could that also reduce my shift points? Quote Link to comment Share on other sites More sharing options...
Brian P Posted September 24, 2004 Report Share Posted September 24, 2004 Instead of disconnecting it outright, you can pull the cable out of adjustment so when you're at WOT, it shifts like as if you were at half throttle, for example. That way you won't have to half ass drive it . Basically grab the end of the TV cable at the throttle body (keep the black clip attached to the throttle too) pull slowly and you will hear clicking. You'll want to hear at least 3 clicks, maybe more. Once you get the hang of it you can fine tune it to your liking. Any other questions feel free to ask. Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 24, 2004 Author Report Share Posted September 24, 2004 When i pull the cable from the TB linkage, id be pulling it in the direction as if id be removing it? Ive never felt any clicks before thats why im asking. Ill be trying whatever ideas i come up with on here this saturday which means ill be "test trying" tomorrow. So if you have any other ideas please share . Also, those three clicks, they'd be really small increments in terms of adjustment right? How big of a change in rpm would that have? And any ideas on the line pressure idea I mentioned? Quote Link to comment Share on other sites More sharing options...
Brian P Posted September 24, 2004 Report Share Posted September 24, 2004 yeah pull the cable towards you. It's really not a linear change in shift points but 3 clicks knocks it down by about 200rpm. You could always go more though! And if you go too far just reset it (push in the button on the housing (back of the plenum) and pull the black cable covering towards the passenger side) Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 24, 2004 Author Report Share Posted September 24, 2004 Hmm. If i didnt have a damn calc test and physics quiz tomorrow id walk over to the parking lot now and try this,lol. I would need a lot more than 200rpm. Right now with the cam the motor dies off around 4grand especially in 2nd because of the gearing. At WOT 2nd shifts around 6100rpm and thats after a couple seconds, i need to let off the gas and the go to about 3/4 throttle to have it shift into 3rd so if i could have the tranny shift before redline, say 5-5500rpm i think itd help alot. Any idea on how much i could adjust that cable? Quote Link to comment Share on other sites More sharing options...
Brian P Posted September 24, 2004 Report Share Posted September 24, 2004 5-6 clicks max. Just do a few at a time and adjust to your liking. Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 24, 2004 Report Share Posted September 24, 2004 I'll be goin' over my car tomorrow, so I can get the lock up - write up for everyone ... Also, if you've ever wondered, when you watch dyno videos, or are on the highway and right 'round 90ish when you hear the motor slow down a bit, that's actually the converter locking up - just so ya know. --Dave. Quote Link to comment Share on other sites More sharing options...
Jon89le Posted September 26, 2004 Author Report Share Posted September 26, 2004 Brian, i tryed adjusting the TV cable and had somewhat of a hard time. I did see what you meant though about where it was. I was in somewhat of a rush trying to adjust it quick enough to make it to the track but im going to try it when i go back home with the motor cold this time . One question though. At the adjustment spot, theres a round covering plate. Which side of that plate do i need to do the adjustment at? Quote Link to comment Share on other sites More sharing options...
Brian P Posted September 26, 2004 Report Share Posted September 26, 2004 adjustment plate? I'm lost. Unless you mean the spot where the reset button is? You don't "alter" the cable there, however. You pull the end of the cable thats clipped onto the w-body um...throttle body :shock: Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.