question ( may be a stupid one )
11-04-2016, 02:12 PM
#1
question ( may be a stupid one ) hello all!
i have a question before i go nutz and tare everything apart,
2000 trans am convertible A4 ( all stock except for long tubes and no EGR/A.I.R.). when i got the car from a local dealer the tranny in the car lasted less then 1000 miles, wouldn't shift out of 2nd gear which sucked. ( 156k on the car ) i swapped it for a known working tranny and it seems to be shifting alright, i can feel each gear, although it shifts hard out of 1st and 2nd and not a good shift hard like a slipping shift hard?? here is the question. when im on the highway i can feel it shift into 4th gear since i can count each time it shifts up but i dont know if its in Overdrive meaning the RPM's arent that low in my opinion. around 70pmh or so its over 2k. when the old tranny worked for the first 1k miles it seemed to be much lower, like on my way to work on the highway i would cruise around 70-75 it would be way under 2k. also with this tranny when im on the highway and give it a little more gas ( not floor it ) it has NO trouble moving. i know that sounds weird, and who complains about going faster but its almost as if its in 3rd gear and not in Overdrive is what i mean. because of this gas mileage sucks. i know its a V8 and its gonna use gas but on a full tank of gas i barely get 200 miles and that doesn't add up to me. Im not a hard driver and im not WOT everywhere i go. any advise guys and gals?
Thanks in advance.
i have a question before i go nutz and tare everything apart,
2000 trans am convertible A4 ( all stock except for long tubes and no EGR/A.I.R.). when i got the car from a local dealer the tranny in the car lasted less then 1000 miles, wouldn't shift out of 2nd gear which sucked. ( 156k on the car ) i swapped it for a known working tranny and it seems to be shifting alright, i can feel each gear, although it shifts hard out of 1st and 2nd and not a good shift hard like a slipping shift hard?? here is the question. when im on the highway i can feel it shift into 4th gear since i can count each time it shifts up but i dont know if its in Overdrive meaning the RPM's arent that low in my opinion. around 70pmh or so its over 2k. when the old tranny worked for the first 1k miles it seemed to be much lower, like on my way to work on the highway i would cruise around 70-75 it would be way under 2k. also with this tranny when im on the highway and give it a little more gas ( not floor it ) it has NO trouble moving. i know that sounds weird, and who complains about going faster but its almost as if its in 3rd gear and not in Overdrive is what i mean. because of this gas mileage sucks. i know its a V8 and its gonna use gas but on a full tank of gas i barely get 200 miles and that doesn't add up to me. Im not a hard driver and im not WOT everywhere i go. any advise guys and gals?
Thanks in advance.
11-04-2016, 04:47 PM
#3
Sounds like converter to me as well. if it was 3rd gear you would be over 3000rpm at 70mph. Are you getting any codes from the trans? if you are going at a constant 70mph on the freeway and you give just a tad bit more gas does the RPM jump a tad? if TCC is locked it wouldn't jump but be completely linear with the speed. If TCC is not engaging you could risk overheating the trans as well since all that wasted energy is heat being dumped into the trans.
11-04-2016, 06:39 PM
#5
then TCC is not locking up. There could be many things causing TCC to not lockup. TCC is fried, TCC valve is not holding pressure, PWM valve not holding pressure, O-ring on input shaft tore (this can happen when installing a converter.... ask me how I know), or you have PWM solenoid or TCC solenoid bad. any one of those things can cause TCC to not work.
11-04-2016, 10:23 PM
#6
Greaaaaaat, any way to narrow it down? Any test I can do? Really wanna swap to a t56 and not dump more money into this auto but as of right now it's my only car and I can't afford or find a good t56 that's not a fortune. Would a bad torque converter also cause late shifts?
11-05-2016, 12:21 AM
#7
There are a couple things to do. First I would try putting a checkball into the TCC solenoid and seeing if when you put your car into gear it'll stall the engine. This test will basically force the TCC valve to engage the TCC all the time so once you put it in gear it should stall the car. If your car does not stall then likely the issue is the converter or O-ring. If it does stall the car then there is likely an issue behind that like in the valvebody. I was diagnosing a similar issue and spent hundreds of $s in parts like valves, seals, kits, and a whole new valvebody and converter. I ended up just buying a junkyard 4l80e and having a local shop rebuild then swapping it with the 60. It ended up that the O-ring was all the what wrong... now I have a perfectly good built 4l60e just sitting around... Anyways good luck.
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11-05-2016, 10:51 AM
#8
Like everybody is saying, it sounds like you've almost verified that the converter is not locking up by the seat of your pants. If it's working properly, you should be able to count what feels like a fourth shift; the rpms drop and part throttle response is poor. If the rpms jump right up at light throttle then it's not locked up.
You can also get hard verification by datalogging without opening up the trans. But if what we're all saying is true, you're going to have to open up the trans anyway.
You can also get hard verification by datalogging without opening up the trans. But if what we're all saying is true, you're going to have to open up the trans anyway.