4L60E 1-2 shift and OD slip
Thread Starter
Teching In
Joined: Mar 2015
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4L60E 1-2 shift and OD slip Hey everyone,
I need your help, I have a 99 trans am. Not much done to it over stock, just a very mild cam and a 2800 stall. Now the trans is giving me two problems.
At first the trans has given me problems shifting at WOT from 1-2. However this doesn't happen all of the time. Sometimes the shift is very smooth and firm, sometimes it hangs at about 6000rpm then shifts.
Now a new issue, just started today, the trans has been having a problem locking up in OD above 70-75mph. The rpms go from about 2000-2200 while I hold the throttle steady.
Anyone know why the trans is doing this, and how I can fix these problems?
I need your help, I have a 99 trans am. Not much done to it over stock, just a very mild cam and a 2800 stall. Now the trans is giving me two problems.
At first the trans has given me problems shifting at WOT from 1-2. However this doesn't happen all of the time. Sometimes the shift is very smooth and firm, sometimes it hangs at about 6000rpm then shifts.
Now a new issue, just started today, the trans has been having a problem locking up in OD above 70-75mph. The rpms go from about 2000-2200 while I hold the throttle steady.
Anyone know why the trans is doing this, and how I can fix these problems?
TECH Fanatic
Joined: Jan 2015
Posts: 1,114
Likes: 33
From: Fort Worth, Texas
It makes me think "sensor" issue, TPS or MAF maybe?
Double check the fluid level, Overfill by a 1/2 quart for testing purposes if nothing else.
Has your car been tuned by a reputable tuner?
Do you have logging capability? (HPtuners)
Double check the fluid level, Overfill by a 1/2 quart for testing purposes if nothing else.
Has your car been tuned by a reputable tuner?
Do you have logging capability? (HPtuners)
Thread Starter
Teching In
Joined: Mar 2015
Posts: 7
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Something interesting happened on my drive home. When the converter unlocks, I put the brake on slightly eith the gas, and when I got off the brake the converter locked back up. Not sure why, maybe this can help pinpoint the problem.
Anyway, my car was tuned by Julio at Cartek, so I think the tune should be fine. Also, I don't have logging capability.
I'm hoping it's something small like a 'sensor' issue, I did see some people with the OD problem say it's a TCC solenoid, but could that be causing my 1-2 shift problem as well? Without logging capability what should I do to try to find the problem?
Anyway, my car was tuned by Julio at Cartek, so I think the tune should be fine. Also, I don't have logging capability.
I'm hoping it's something small like a 'sensor' issue, I did see some people with the OD problem say it's a TCC solenoid, but could that be causing my 1-2 shift problem as well? Without logging capability what should I do to try to find the problem?
TECH Fanatic
Joined: Jan 2015
Posts: 1,114
Likes: 33
From: Fort Worth, Texas
The brake switch has 2 sets of contact, A N/C set for the TCC & a N/O set for the brake lights. The switch could be bad or out of adjustment, A new Delco switch is cheap enough.
I would need to know if the 1-2 shift is being commanded or not when it hangs on you.....Along with the TPS & VSS readings.
I would need to know if the 1-2 shift is being commanded or not when it hangs on you.....Along with the TPS & VSS readings.
Thread Starter
Teching In
Joined: Mar 2015
Posts: 7
Likes: 0
The brake switch has 2 sets of contact, A N/C set for the TCC & a N/O set for the brake lights. The switch could be bad or out of adjustment, A new Delco switch is cheap enough.
I would need to know if the 1-2 shift is being commanded or not when it hangs on you.....Along with the TPS & VSS readings.
I would need to know if the 1-2 shift is being commanded or not when it hangs on you.....Along with the TPS & VSS readings.
