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4L60E slipping on 1-2 shift

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Old Feb 3, 2020 | 08:44 AM
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Default 4L60E slipping on 1-2 shift

Last night coming home I noticed my car seemed really sloppy in 2nd gear. Well this morning, it's started to really slip the 1-2 shift, it use to be pretty snappy. The 2-3 shift is still firm. Is the trans on its way out or is it just a simple fix? It has no check engine lights and the car has 120k miles on it.
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Old Feb 3, 2020 | 09:05 AM
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See how many qts you are low on fluid...that's the first place to look.

But, when you say it's slipping the one two...what exactly do you mean? Like it takes a while to engage? Feels like it "slides" into gear?

etc
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Old Feb 3, 2020 | 10:00 AM
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Feels exactly like that, it disengages 1st then slowly revs up and slowly catches 2nd. I'll check my fluid.
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Old Feb 3, 2020 | 01:08 PM
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it does not disengage 1st.
1st gear has the fwd clutches engaged
2nd gear needs the fwd clutches AND the band.
So...1st never gets "disengaged"
Even if you left the band out of the trans...1st isn't going to "disengage"...it will just stay in 1st gear

Are we sure there's not some placebo effect here?

If it's just lazy...you can do a pressure test, but it is not uncommon for the band clearance to get farily loose and shift lazily.
There are other VB issues to check, but easiest checks are line pressure and band clearance (use a pry bar against the servo cover and estimate travel. More than 1/8" is no bueno
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Old Feb 3, 2020 | 05:08 PM
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Thanks for correcting me! I'm Newbie, when it comes to this stuff.
it's definitely not placebo, if I give it too much gas in 2nd, it revs up like it's in neutral.
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Old Sep 23, 2024 | 10:59 PM
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Originally Posted by MaroonMonsterLS1
See how many qts you are low on fluid...that's the first place to look.

But, when you say it's slipping the one two...what exactly do you mean? Like it takes a while to engage? Feels like it "slides" into gear?

etc
hey i also have that problem. im not sure when it happened but it was random, i was driving normal and everything was shifting fine. a few hours later i was starting a race in 1st and floored it. this time instead of the smooth shift it redlined and i letoff then it shifted. it shifts late from 1-2, my vss is off and so is my tps. what do yall think?
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Old Sep 24, 2024 | 09:07 AM
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Old thread, but I'll come back to it. Mine ended up being 2-4 band. Which never made sense to me since 4th gear worked perfectly fine. I just bought a built trans to replace the stock one. I did drive it around like that for months though so if you need time to save to rebuild you can do so. No clue what causes the band to get excessive clearance as I'm not a trans expert. But I think if you're having the SAME problem, it's safe to assume it's the same issue. 1st, 3rd and 4th gear under load is fine and 2nd gear just free revs like it's in neutral.

Get your VSS and TPS sorted out before you start digging into a trans problem though.
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Old Sep 24, 2024 | 10:12 AM
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Originally Posted by JonAdkins
Old thread, but I'll come back to it. Mine ended up being 2-4 band. Which never made sense to me since 4th gear worked perfectly fine. I just bought a built trans to replace the stock one. I did drive it around like that for months though so if you need time to save to rebuild you can do so. No clue what causes the band to get excessive clearance as I'm not a trans expert. But I think if you're having the SAME problem, it's safe to assume it's the same issue. 1st, 3rd and 4th gear under load is fine and 2nd gear just free revs like it's in neutral.

Get your VSS and TPS sorted out before you start digging into a trans problem though.
Many forget that when dealing with band clearance. You are actually dealing with 2 clearance not 1. One is 4th servo to band pin the other second servo to band pin and second is a bit more complicated with the cushion spring being part of it. You can have a solid perfect 4th servo clearance and still have excessive second servo as the second servo cushion spring cover must not only hit but fully compress the spring for one to have full apply in second.
So you are dealing with 2 clearances no just one. I go into this in the 4l60e tech thread and my build thread.
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Old Sep 24, 2024 | 10:53 AM
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Originally Posted by FranksCustomTrans
Many forget that when dealing with band clearance. You are actually dealing with 2 clearance not 1. One is 4th servo to band pin the other second servo to band pin and second is a bit more complicated with the cushion spring being part of it. You can have a solid perfect 4th servo clearance and still have excessive second servo as the second servo cushion spring cover must not only hit but fully compress the spring for one to have full apply in second.
So you are dealing with 2 clearances no just one. I go into this in the 4l60e tech thread and my build thread.
Frank you actually built my trans for me years ago when you were at Performabuilt. You are a great man!
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Old Sep 24, 2024 | 11:43 AM
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Originally Posted by jonadkins
frank you actually built my trans for me years ago when you were at performabuilt. You are a great man!
thanks much and glad it was good for you
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