4l60e hitting limiter on 1-2 and 2-3 shift
4l60e hitting limiter on 1-2 and 2-3 shift ok so the back story is i lost 3-4 clutch pack last fall in the middle of street tuning the car. rebuilt the transmission with all the common/proper upgrades for a modified car. car has a circle d 4c 3800 stall in it.
since i got the car i could never figure out why it felt so slow, recently i installed a nitrous kit with a NOS TPS WOT window switch and realized that the aftermarket TB that the previous owner had installed was not opening all the way on WOT because they never adjusted the throttle cable. prior to this discovery the car had been shifting flawlessly at the 3/4 "WOT" that it was able to do.
fast forward to this week after fixing the issue now it will not make the 1-2 or 2-3 shift without bouncing off the rev limiter. ive tried to make every change possible in HP tuners to make it shift. ive lowered and/or zeroed out the WOT and part throttle MPH based shift times as well as lowered the RPM based shift points to as low as 4800 and it still will not shift without hitting the 6500 RPM limiter. if i put the car in D1 and manually shift from D1 to D2 it will shift without hitting the limter but will not shift from D2 to D3 without hitting limiter.
i did a 1-2-3 pull on the highway and logged it. hoping someone can give me an idea of where i should start looking for problem. at this point i have to assume its mechanical even though the transmission shifts flawless outside WOT.
since i got the car i could never figure out why it felt so slow, recently i installed a nitrous kit with a NOS TPS WOT window switch and realized that the aftermarket TB that the previous owner had installed was not opening all the way on WOT because they never adjusted the throttle cable. prior to this discovery the car had been shifting flawlessly at the 3/4 "WOT" that it was able to do.
fast forward to this week after fixing the issue now it will not make the 1-2 or 2-3 shift without bouncing off the rev limiter. ive tried to make every change possible in HP tuners to make it shift. ive lowered and/or zeroed out the WOT and part throttle MPH based shift times as well as lowered the RPM based shift points to as low as 4800 and it still will not shift without hitting the 6500 RPM limiter. if i put the car in D1 and manually shift from D1 to D2 it will shift without hitting the limter but will not shift from D2 to D3 without hitting limiter.
i did a 1-2-3 pull on the highway and logged it. hoping someone can give me an idea of where i should start looking for problem. at this point i have to assume its mechanical even though the transmission shifts flawless outside WOT.
trans rebuild list
trutech "raybestos stage one" rebuild kit
sonnax smart shell
sonnax input drum reinforcement sleeve
sonnax HD 2-3 shift valve
sonnax performance pack
new solenoids
new reverse input drum
transgo seperator plate
trutech "raybestos stage one" rebuild kit
sonnax smart shell
sonnax input drum reinforcement sleeve
sonnax HD 2-3 shift valve
sonnax performance pack
new solenoids
new reverse input drum
transgo seperator plate
Moderator
Joined: Aug 2010
Posts: 7,322
Likes: 527
From: Ann Arbor, MI
Yes, you need to confirm that your trans line pressure is hitting around 225psi at WOT.
I suspect it is not.
If not, the next step is to log the EPC current in HP Tuners Scanner; it should be near zero at WOT.
If the current is NOT near zero, then you have a sensor or tune problem.
If you current is near zero, but your line pressure is below 225psi, then you should replace the EPC in the trans which is quite easy after dropping the pan.
Your TruTech rebuild parts look like a good combo.
I would add the Sonnax Boost valve, especially because the stock one can start leaking due to wear and therefore not be able to reach sufficient line pressure. Again this is easy to install after dropping the pan.
I suspect it is not.
If not, the next step is to log the EPC current in HP Tuners Scanner; it should be near zero at WOT.
If the current is NOT near zero, then you have a sensor or tune problem.
If you current is near zero, but your line pressure is below 225psi, then you should replace the EPC in the trans which is quite easy after dropping the pan.
Your TruTech rebuild parts look like a good combo.
I would add the Sonnax Boost valve, especially because the stock one can start leaking due to wear and therefore not be able to reach sufficient line pressure. Again this is easy to install after dropping the pan.
they pump does have the sonnax boost valve as it comes in the performance pack. i replaced all solenoids and wire harness tonight and it didnt change anything.
if you watch the log the force motor is jumping anywhere from 50-96% while wot. you can see the car trying to command 3rd gear and it keeps jumping back and forth from 2 to 3 starting about 6000rpm until it finally shifts after it bumps rev limit.
the only thing i havent tried is checking line pressure which i will do this weekend.
if you watch the log the force motor is jumping anywhere from 50-96% while wot. you can see the car trying to command 3rd gear and it keeps jumping back and forth from 2 to 3 starting about 6000rpm until it finally shifts after it bumps rev limit.
the only thing i havent tried is checking line pressure which i will do this weekend.
Moderator
Joined: Aug 2010
Posts: 7,322
Likes: 527
From: Ann Arbor, MI
Sorry I missed that the Sonnax Performance Pack was included; the TruTechTrans kits are using all the latest parts.
I think we need to wait for the line pressure test as nothing else is obvious.
What year is the trans?
I'd like to look at your tune too.
I think we need to wait for the line pressure test as nothing else is obvious.
What year is the trans?
I'd like to look at your tune too.
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couldnt get ahold of a pressure gauge so im going to order one tonight. trans started randomly acting up today with flare shifts and slipping while under lockup part throttle and throwing a hand full of codes for the transmission but i erased them without writing them down, so i started logging to see if anything was suspect and ended up doing a WOT pull where it bumped the limiter hard, and then all the sudden it went back to shifting normal at part throttle.
then on my way back home i went wot from 3rd gear and the car tried to downshift to 2nd but kept bouncing back between 2nd and 3rd. like it couldnt make up its mind which gear to be in. ill post the log, the issue starts at about 1:25 into the log.
anyways heres the map, im new to this so im certain its probably something i screwed up and didnt realize. let me know what errors you see.
then on my way back home i went wot from 3rd gear and the car tried to downshift to 2nd but kept bouncing back between 2nd and 3rd. like it couldnt make up its mind which gear to be in. ill post the log, the issue starts at about 1:25 into the log.
anyways heres the map, im new to this so im certain its probably something i screwed up and didnt realize. let me know what errors you see.
ok to update this, the problem is fixed (for now).
i ended up copying over the transmission portion of an HPT sample file and now it shifts when commanded at 6k and does it pretty well (a little softer then i would expect).
i ended up copying over the transmission portion of an HPT sample file and now it shifts when commanded at 6k and does it pretty well (a little softer then i would expect).
TECH Resident
Joined: May 2006
Posts: 969
Likes: 119
When using the TransGo separator plate (or any other separator plate) the feed holes must be the right size for the torque converter stall and diameter and rear end gear ratio too. With what you have mentioned here, the 1-2 shift feed hole should be .093" - .099". The 2-3 shift feed hole should be .120". 3-4 shift feed hole should be .125". Band release hole should be .082", if larger bring it down. Forward clutch feed hole .086". With the TC and running nitrous here it should help a lot. This is assuming the 3-4 clutches are still ok. How many clutches are in the 3-4 clutch pack here? And what type?
