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Tranny problems shifting at WOT

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Old 08-04-2012, 08:28 PM
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Default Tranny problems shifting at WOT

Just bought the car not too long ago. Car is a white 00 T/A, with Head/Cam, exhaust, fast intake, 4000 precision ind stall, etc. Everything seems to be working like it should except the tranny @ WOT. (well at around 50-55 on OD, i feel some sort of slight jerkin on the drive train, dunno if its stall related, but if i go 3d its fine)

I opened the car up and went WOT the other day in auto 3d mode and also tried to manual shift it, but she seems to hit the limiter and over revs type of deal. On Auto mode 1st to 2nd shifts good but at only 5500 rpms (dunno if that's the correct rpm) i leave my foot planted and on the 2nd to 3rd shift she acts like its hitting the limiter and has a delay going into 3rd while hittin the limiter few times, it has the same issue on manual shift mode, even from 1st to 2nd, any ideas? One of my friends that's been wrenching for some time, and works at a tranny shop ATM, took her for a spin and said it doesn't feel like the issue its internal, since she doesn't seem to slip or do anything out of the ordinary, but more like an electrical prob. We connected a obdII scanner he has and she's throwing a TPS sensor code, just trying to figure out if that could be the problem or if i should look somewhere else..Any help is appreciated..
Old 08-04-2012, 11:54 PM
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The TPS is likley the issue or the tune in general the trans is totally dependent on these
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Old 08-09-2012, 06:38 AM
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Changed the TPS sensor out, codes are gone but she still the same. First time i went WOT yesterday i was in 2nd and went to 3rd and to my surprised she shifted fine, but everytime after i started in 1st from a 30 punch then went to 3d she started actin again..
Old 08-09-2012, 07:29 AM
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when cold tranny fluid could read whatever? I just pulled the dipstick before leavin to work, and oil level was too high, by the writing that says when hot oil level should be on the 'hot' cross hatch.. level was by 'hot'
Old 08-09-2012, 07:43 PM
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Tps code p0121, showing up again on the scanner with the new tps sensor. Tranny fluid when engine hot, shows about 2 inches more than the cross hatch but i could barely read it since its not a solid mark (dunno if i can explain it right) like its not fully wettin the dipstick, any help is appreciated, tnx
Old 08-11-2012, 08:17 AM
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Default WOT Tranny shift prob.

Just had the same problem this past few weeks. Car would bounce off the rev lim. going from 2-3 wot, sometimes would shift, sometimes not. also didnt act right on downshifts from 3-2 sometimes. Didnt think it was an internal problem cause i had the 3-4 clutch paks replaced about 6 mos. go.. But couldnt think of anything else it could be so i had my tranny guy (new tranny guy), tear her apart, found 3-4 clutches nearly burned up and a few other problems which were supposed to be addressed the last time i had it rebuilt.. Now with a good set of clutches and several other improvements in the trans she shifts spot on nice and firm and crisp.. So point of story don't overlook possibility of failing trans....sorry and goodluck!!!!
Old 08-11-2012, 07:32 PM
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Originally Posted by suvettetexas
Just had the same problem this past few weeks. Car would bounce off the rev lim. going from 2-3 wot, sometimes would shift, sometimes not. also didnt act right on downshifts from 3-2 sometimes. Didnt think it was an internal problem cause i had the 3-4 clutch paks replaced about 6 mos. go.. But couldnt think of anything else it could be so i had my tranny guy (new tranny guy), tear her apart, found 3-4 clutches nearly burned up and a few other problems which were supposed to be addressed the last time i had it rebuilt.. Now with a good set of clutches and several other improvements in the trans she shifts spot on nice and firm and crisp.. So point of story don't overlook possibility of failing trans....sorry and goodluck!!!!
thanks for the heads up, i'm going to start from simplest/cheap fix to expensive process of elimination type of deal. Mine when I first go WOT from 2nd to 3rd shifts ok , but then if I go from 1st 30 punch to 2nd and then 3rd she bounces off the limiter, she had about 1.5 to 2 quarts excess of tranny fluid. I drain some out and now she's about right, hopefully its true what they say about having more then the needed fluid would make the tranny act weird..just waiting on a day that won't rain from now 0n to test her out..
Old 08-15-2012, 05:34 PM
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did you get this prblem figured out? I am sometimes getting this problem as well. I figure i may have to replace 2-3 clutches???
Old 08-20-2012, 08:49 PM
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Having a similar issue, any updates?
Old 08-20-2012, 09:20 PM
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This is probably the second most common question asked here. Here are some similar threads:
https://ls1tech.com/forums/automatic...-shifting.html
https://ls1tech.com/forums/automatic...ts-needed.html

At WOT the transmission will not shift until both the tuned RPM -AND- MPH are reached. The factory tune has these tightly related; IMHO tighter than they need to be. Therefore, if there is any slippage which drops the MPH by even a few mph at e.g. 5000 or 6000 rpm, then you will hit the rev limiter before the transmissions shifts.
The most common reason for "slippage" are:

1. An aftermarket high stall torque converter
2. Any wear in the transmission, e.g. a slipping band or slipping 3/4 clutch
3. A defective VSS could imitate slippage even when there is none.

In addition, any defective sensor like the TPS, MAP or MAF will confuse the PCM and result in all kinds of problems, including this one.

Typically when a high stall torque converter is installed, the PCM has to be retuned to reduce the shift MPH by a few mph so that it shifts before redline.

Therefore, if the problem suddenly comes on without any engine/trans mods, first check that all sensors are working; be sure to look for any codes and fix them first. It its not that, then start saving your $$$ for a likely transmission rebuild in the near future. As I have mentioned in other posts, installing a shift kit or at least a .500 boost valve to increase line pressure might extend the life of the trans by "a bit". (1000 miles, 10,000 miles, I don't know.)



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