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4L60 1st Gear Shifting Issues

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Old 07-02-2015, 08:41 AM
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Default 4L60 1st Gear Shifting Issues

Ok so here's my problem. Car shifts and drives perfect under normal driving conditions. However If I hammer it from a dead stop, when it goes to the first shift which should be 1~2 gear shift it bounces off of the rev limiter badly. Thought and suggestions as to what may be going on with it. The 1~2gear change is set about 6050 RPM and my rev limiter is set about 7100.

Motor makes close to 500 RWHP before N20. I also am running a Yank 3600 convertor. Any ideas or suggestions as to what the issue may be would be greatly appreciated.

Thanks,
Eric
Old 07-02-2015, 11:10 PM
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Check the end play of the servo; excessive end play indicates the band is worn.
Using a crow bar and a ruler press down on the servo cover and estimate how much it moves.
Between about 1/16" and 1/8" is within spec. By 3/16" the band often starts to slip in either 2nd or 4th gear.
Old 07-03-2015, 06:09 AM
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Originally Posted by mrvedit
Check the end play of the servo; excessive end play indicates the band is worn.
Using a crow bar and a ruler press down on the servo cover and estimate how much it moves.
Between about 1/16" and 1/8" is within spec. By 3/16" the band often starts to slip in either 2nd or 4th gear.
Mrverdit thanks for your input, however I think my problem is much deeper than I originally thought. It won't shift out of any gear at all now. I've got to decide which direction that I want to go now.
Old 07-03-2015, 12:12 PM
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The basic tools for transmission diagnosis are a scanner that can command gears and trans pressure gauge.

Are you saying it is stuck in 1st?
Does the car start in 2nd gear if you shift to [D2]?

I would want to rule out the shift solenoids and the PCM before pulling the trans, assuming the servo end play was OK.



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