Since I last posted on this subject Ive done some extensive test driving and have come up with a better explaination of the problem and its symptoms. Forget what I said before. I should have done this first before asking questions but heres the new info.
First of all heat is not a factor because the trans will act up weather warm or cold. Now, I can leave from a stop, and as long as I dont give it more than 1/4 throttle the trans will function normally and upshift thru all gears perfectly. I can do this all day long without any problems. Now, the symptoms of failing to upshift to 3rd will arise whenever I either, get on it good with more than 1/2 throttle, or if I punch it from a roll and cause a kickdown. After doing either of these the trans will act up and not upshift under light throttle. So, half throttle thru first and into 2nd then let off. One would expect it to then eventually go into 3rd. But it wont. I also discovered how to make the symptoms and problem go away, and I did this a dozen times with the same results. When the trans acts up and wont shift, I pull over and come to a complete stop, put the trans into reverse for a second, pull it back into D and go. Upshifts fine and problem is gone, so long as im easy on the throttle. Something about putting into reverse must be raising the pressure and causing a sticking valve to be pushed back to its normal position. When it acts up and I come to a complete stop and "dont" first put it into reverse then back into D before pulling away again, it will shift very very hard into 2nd but then fail to shift into 3rd. So, when it acts up, its obvious that the pressure is really high, even at light throttle, hence the very hard shift from 1st to 2nd. And this is with light throttle so the pressure shouldnt be that high at that throttle position. One transmission guy has already suggested that the throttle valve might be hanging up in the valve body, and by selecting reverse the pressures are raised enough to push it back where it should be. He said that its possible that each time I push the pedal down far enough the valve gets to the point where its hanging up, and that when I stay on light throttle it doesnt bind and functions normally. Makes sense to me. Whatta you think? Im gonna drop the pan and valve body, and remove the throttle valve components, clean and polish them and make sure the bore is clean. Ill give this a try anyway. Ill try anything to avoid pulling this tranny. Ill also check really good for metal filings and whatnot since its possible that something else is failing and debris got in there to hang up the valve. Could be a piece of dirt from cooler line or convertor or anywhere else. Could have got in there thru a dirty funnel when filling. So to the tranny experts, whatta do you think? Does this senerio of symptoms match a sticking throttle valve? Im goin in there to check and clean up and ill post back and let you know if it does or does not solve the problem.
First of all heat is not a factor because the trans will act up weather warm or cold. Now, I can leave from a stop, and as long as I dont give it more than 1/4 throttle the trans will function normally and upshift thru all gears perfectly. I can do this all day long without any problems. Now, the symptoms of failing to upshift to 3rd will arise whenever I either, get on it good with more than 1/2 throttle, or if I punch it from a roll and cause a kickdown. After doing either of these the trans will act up and not upshift under light throttle. So, half throttle thru first and into 2nd then let off. One would expect it to then eventually go into 3rd. But it wont. I also discovered how to make the symptoms and problem go away, and I did this a dozen times with the same results. When the trans acts up and wont shift, I pull over and come to a complete stop, put the trans into reverse for a second, pull it back into D and go. Upshifts fine and problem is gone, so long as im easy on the throttle. Something about putting into reverse must be raising the pressure and causing a sticking valve to be pushed back to its normal position. When it acts up and I come to a complete stop and "dont" first put it into reverse then back into D before pulling away again, it will shift very very hard into 2nd but then fail to shift into 3rd. So, when it acts up, its obvious that the pressure is really high, even at light throttle, hence the very hard shift from 1st to 2nd. And this is with light throttle so the pressure shouldnt be that high at that throttle position. One transmission guy has already suggested that the throttle valve might be hanging up in the valve body, and by selecting reverse the pressures are raised enough to push it back where it should be. He said that its possible that each time I push the pedal down far enough the valve gets to the point where its hanging up, and that when I stay on light throttle it doesnt bind and functions normally. Makes sense to me. Whatta you think? Im gonna drop the pan and valve body, and remove the throttle valve components, clean and polish them and make sure the bore is clean. Ill give this a try anyway. Ill try anything to avoid pulling this tranny. Ill also check really good for metal filings and whatnot since its possible that something else is failing and debris got in there to hang up the valve. Could be a piece of dirt from cooler line or convertor or anywhere else. Could have got in there thru a dirty funnel when filling. So to the tranny experts, whatta do you think? Does this senerio of symptoms match a sticking throttle valve? Im goin in there to check and clean up and ill post back and let you know if it does or does not solve the problem.
