4 speed auto just slams into second; is that normal?

[try2pas]

I have a 4L70E trany and it just slams into second. Will "bark" the tires even. I am beginning to flinch when it shifts. What could be going on?

 

[Hib Halverson]

Has it always done that on the 1-2 shift?

 

[try2pas]

NO for about a year and then a couple of years ago it started, but only about 25% of the time. It has progressively gotten worse. So I had all the fluid changed. Then I had the solenoids replaced. Then I had it recently into a shop and the codes said "lost communication" so they found a wire that wasn't hooked up very well. They fixed that and now it doesn't have any codes but still does it. Last May, after I autocrossed hard in second it didn't do it for quite a while. But it's hard at it now.

 

[Hib Halverson]

If there are no DTCs set in the trans controller, the problem did not exist at first but then, after it began to occur, it's gotten steadily worse, I'd say you likely need trans service but...I'd get the opinion of an auto trans service facility which you trust.

 

[BigJimZ16]

Kind of sounds like what happens when someone screws around with the shift pressures using a handheld performance programmer like a Hypertech...

 

[Chevy Customer Service]

I have a 4L70E trany and it just slams into second. Will "bark" the tires even. I am beginning to flinch when it shifts. What could be going on?

Hi Try,

I wanted to check in with you. How is everything going with your Corvette? Have you had the trans looked at like Hib suggested? Keep us posted and if there is anything I can do.

Hey Hib, I wanted to apologize to you! I dropped the ball on helping you with your HVAC issues in your Z. If you are still having those concerns, I would like to continue getting that case set up for you. Please let me know,

Kelly J.
Chevrolet Customer Care

 

[Hib Halverson]

(snip)

Hey Hib, I wanted to apologize to you! I dropped the ball on helping you with your HVAC issues in your Z. If you are still having those concerns, I would like to continue getting that case set up for you. Please let me know,

Kelly J.
Chevrolet Customer Care

PM Sent

 

[Boshboo]

Common failures 4L60-65-70 0E

Several years late. How did it go ???


I have not done anny 4L70E How ever this may help you find the problem:

First I would do this.
Chech for codes.
Then check the line pressure so it behave right, low pressure in idle, high when you floor it, (after the shift whit a little delay 0.5-1 sec.)
( It is hard to describe but the pressure should behave smooth and rappid like the throttel respons. )

Linepressure (4l60E)
http://www.hotrodders.com/forum/attachment.php?attachmentid=55613&d=1306594427


Second:
If it does not behave like that chech the ATF manifold and 1-2 Accumulator.
They are inside the pan.

Third rebuld:

Pictures:
Common failure parts to 4L60E:

ATF manifold 4L60E Pressure Switch | eBay
1-2 Accumulator 4l60e accumulator pistons in Parts & Accessories | eBay
Assembly 4L60E Disassembly

Boshboo