4l60e Late Shifting
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Teching In
Joined: Oct 2016
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4l60e Late Shifting So I just got my 1999 pontiac trans am 4l60e from the shop from it getting a mild cam. Transmission was rebuilt with aftermarket clutches etc 4 months ago. It drover nice after leaving there shop and to my house. Later that night I was manuel shifting it from 1st to the most 3rd gear and later on while in d4 gear from dead take off didn't want to shift til 4k-5k rpm's. That with me playing with throttle to make it shift. And when I punch it while going about 60 mph itll just redline a few times and keep doing it until I play with throttle to make it shift. All other gears shift smooth. So scanned the engine light and it showed "solenoid a circuit stuck on". I went to auto parts store got the solenoid and fluid, dropped the pan "clean and a whistle" by the way. Put part in and still does same thing except it'll shift in 3k rpm range now if I play with throttle. Fluid level has been good and clean. Tranny is 4 months old with aftermarket internals. Stock stall. Tried disconnecting the battery as well. Please help on a budget and don't want to take it to a tranny shop for them to screw me over.
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Joined: Aug 2010
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From: Ann Arbor, MI
Playing with the car did not "throw off the tune", not even the adaptive settings.
You need to connect a scanner that shows when the PCM is commanding the shift.
The solenoid code indicates there might be significant slippage.
Is the 2-> 3 shift the problem or all shifts?
You need to connect a scanner that shows when the PCM is commanding the shift.
The solenoid code indicates there might be significant slippage.
Is the 2-> 3 shift the problem or all shifts?
Hmm shifting issues after power adders, Need a little more info What stall is the converter, With the additional power may be enough slip in the converter assuming high stall to trigger that code though its a false code if so can be corrected in tuning by turning off that code, Some cars run higher stalls and never set that code till you change something, .
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Thread Starter
Teching In
Joined: Oct 2016
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4l60e reply Sorry for late response but I found out some things. Took it to tranny shop and all they told me was there were no codes.. next day took it to my hp tuner and he hooked his laptop up to it and seen that 2nd gear completely don't work. 1st works, 3rd, 4th and reverse work perfectly. I've changed the solenoids. Fluid was red/pink. Pan was clean as well. If I don't let my foot off the gas it will automatically go to 3rd gear from 1st around 4500 rpm. Thinking about trying a new tranny shop and have them repair it. Was told it's a harness, servo, or accumilator. Thoughts?
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Joined: Aug 2010
Posts: 7,323
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From: Ann Arbor, MI
I don't know if a completely cracked piston in the 1-2 accumulator would give a complete loss of 2nd gear, but it sure is easy to check and correct.
An electrical problem (shift solenoid, harness) would result in the loss of 2 gears not just one.
A problem in the servo with the 2nd apply piston is a distinct possibility.
With a many-miles trans I would suspect a worn band, but it sounds like you have a new one. Band wear is checked by pressing on the servo cover (with e.g. a crowbar) and measuring end play. It should be .075 to .125"; much more indicates a worn band.
An electrical problem (shift solenoid, harness) would result in the loss of 2 gears not just one.
A problem in the servo with the 2nd apply piston is a distinct possibility.
With a many-miles trans I would suspect a worn band, but it sounds like you have a new one. Band wear is checked by pressing on the servo cover (with e.g. a crowbar) and measuring end play. It should be .075 to .125"; much more indicates a worn band.
Launching!
Joined: Feb 2015
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I don't know if a completely cracked piston in the 1-2 accumulator would give a complete loss of 2nd gear, but it sure is easy to check and correct.
An electrical problem (shift solenoid, harness) would result in the loss of 2 gears not just one.
A problem in the servo with the 2nd apply piston is a distinct possibility.
With a many-miles trans I would suspect a worn band, but it sounds like you have a new one. Band wear is checked by pressing on the servo cover (with e.g. a crowbar) and measuring end play. It should be .075 to .125"; much more indicates a worn band.
An electrical problem (shift solenoid, harness) would result in the loss of 2 gears not just one.
A problem in the servo with the 2nd apply piston is a distinct possibility.
With a many-miles trans I would suspect a worn band, but it sounds like you have a new one. Band wear is checked by pressing on the servo cover (with e.g. a crowbar) and measuring end play. It should be .075 to .125"; much more indicates a worn band.
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Joined: Aug 2010
Posts: 7,323
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From: Ann Arbor, MI
Could the shop have installed a new band onto a worn drum? I know on the 2 4L60es ive had apart, one had noticable wear on the drum that probably would not have let a new band grab very well. In my mind that may explain why it was working and then quit working. Im no expert, but just a thought.
It seems that the original factory 4L60E are very durable with many millions of them lasting 15+ years and 150,000+ miles. Then after a "typical" local rebuild they barely last at all. I'm confident that in nearly all of these cases, the rebuilder skipped time-consuming steps and didn't replace all the worn parts in the interest of keeping the price down and/or profit up.
This will be the case for any 4L60E rebuild costing less than about $1800 with labor to remove and reinstall.
Another possibility is that an engine or PCM malfunction causes the trans to quickly burn out due to low line pressure. A quality installer should be testing that with a scanner and pressure gauge.
The current sponsors all sell top quality rebuilds. It still requires a quality installer who knows how to install a converter while measuring the gaps and tests that the PCM is correctly commanding sufficient line pressure.
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