4L60-E Problems. Help.

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Chuff
Posts: 267
Joined: Thu Dec 20, 2012 5:28 pm
Location: Melbourne

4L60-E Problems. Help.

Post by Chuff »

Hi all,

About 3 months ago my son finally bought his first Gen3 Commodore, a VY Ute, and up until yesterday it was faultless. Needing to put fuel into it, he pulled into the servo, filled it up, and upon leaving he had lost 2nd & 4th gears. Prior to this there was no problem.

So in a vane hope that a service might remedy it I changed the filter and renewed 5 liters of ATF and, sadly, no joy.

It's got 248K on the clock, so it would be no surprise if it's lived it's life and is need of a rebuild, but to go from absolutely no problems to a complete loss of 2nd & 4th leads me to hope that it may be something that can be rectified allow him use of his car while he saves up for a rebuild.

Could this be caused by a failed shift solenoid in the valve body?

Also, could hooking up a Tech2 reveal anything which may be helpful?

Any help appreciated.

Thanks in advance.

Chuff
˙ʎɐqǝ ɟɟo pɹɐoqʎǝʞ ǝsǝuıɥɔ ɐ ƃuıʎnq ɹoɟ ʇɥƃıɹ ǝɯ sǝʌɹǝs
MAGP
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Joined: Tue May 10, 2016 5:48 pm
cars: VC V8 sedan, VS V6 wagon, VT V8 Landcruiser.

Re: 4L60-E Problems. Help.

Post by MAGP »

Chuff wrote:Could this be caused by a failed shift solenoid in the valve body?
Yes, had similar things happen in my VS a few times over the years.
Chuff wrote:Also, could hooking up a Tech2 reveal anything which may be helpful?
If it is something that would bring up a fault code.
First thing I would do is a fault code check, if it shows something then come back and let us know. If you can do it with a Tech 2 it will give you a procedure to follow for diagnosis. If you do it manually you will need a workshop manual to follow the diagnosis guide. If nothing shows then it probably isn't a solenoid and may be deeper and more expensive.
Chuff
Posts: 267
Joined: Thu Dec 20, 2012 5:28 pm
Location: Melbourne

Re: 4L60-E Problems. Help.

Post by Chuff »

Thanks MAGP.
MAGP wrote:If it is something that would bring up a fault code.
Would a faulty solenoid valve throw a code?

Upon turning on the ignition the "System Check" on the dash gives a result of "OK" so I guess that means no codes. I'm not familiar with VY Commodores, so I have no idea if there's a more comprehensive check I can run without a Tech2 or diagnostic software (Eg. "MODE" "UP/DOWN" button combinations during ignition). I'll be Googling that now to find out.

Also, I don't have access to a Tech2 or diagnostic software so a manual diagnosis it will have to be, and I don't have a workshop manual for it either, so I'll be Googling that as well.

If anyone knows of a link to a workshop manual PDF then please share?

Thanks for the reply. It gives my some leads for further investigation.

Chuff
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MAGP
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Re: 4L60-E Problems. Help.

Post by MAGP »

Chuff wrote:Thanks MAGP.
MAGP wrote:If it is something that would bring up a fault code.
Would a faulty solenoid valve throw a code?
They do in my VS.
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The1
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Re: 4L60-E Problems. Help.

Post by The1 »

Going from memory, 2nd and 4th are on different solenoids, so unlikely. 2nd and 4th both use the band to apply, so band might be broken or wornout. Do you have reverse?
Chuff
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Joined: Thu Dec 20, 2012 5:28 pm
Location: Melbourne

Re: 4L60-E Problems. Help.

Post by Chuff »

Thanks The1. I reckon you're on to something.

I did some research and took the car for a longer drive to get a much better idea as to what's going on and I agree with your statement about the solenoids and the band. Using this chart (http://imgur.com/sBOAnPCl.png) and the symptoms below I have made some conclusions.

Reverse works fine.
1st gear works fine and overrun clutches apply on deceleration.
2nd gear has no noticeable grab/motion or overrun clutch application.
3rd gear works fine and overrun clutches apply on deceleration.
4th gear does engage but as soon as any acceleration is applied it begins to slip. Overrun clutches seem to apply on deceleration.

Since 1st & 3rd are working fine, the chart tells me that both the 1-2 & 2-3 shift solenoids are being applied and operating correctly. This leaves the band as being the only possible cause, but what has me confused is how it could be running perfectly fine as the car is driven into the servo, and upon leaving it has lost 2nd & 4th. If the band had worn then I would expect a gradual deterioration appearing as slipping in 2nd and/or 4th as opposed to being so sudden.

The fact that I am getting some grab in 4th leads me to eliminate the possibility that the band anchor point, or the band itself, has failed, so I believe I can eliminate these 2 possibilities as the cause. This leads to the only conclusion I can come to, and that is that an O ring has let go on the 2-4 servo. This would explain the sudden loss of the gears, as opposed to the gradual deterioration of the band wearing out & slipping, and the fact that I am getting some grab in 4th leads me to believe that the band and servo are working, but the faulty O ring is not allowing the servo to maintain a high enough pressure to hold the band.

Well that's my theory anyway.

So unless someone can fault my logic, or add something else I have yet to consider, the 2-4 servo is coming out tomorrow for a look-see. Fingers crossed I find a faulty O ring and that will be the end of it. Fixed. I have a couple of new replacements O rings lying around from previous rebuilds I have done so it should cost junior $0, which not only makes his life better, but more importantly, mine too. :D

Since the servo is coming out, does any know if the 4L60-E in the VY Commodores came out with a Corvette servo? I'm pretty sure I have a spare so it would only a good thing upgrading as the pressure increase on the band couldn't hurt.

Comments?

Thanks everyone.

Chuff
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The1
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Re: 4L60-E Problems. Help.

Post by The1 »

can't hurt to check servo's, but it's possible the band has a crack where the pin puts pressure on it, it just happened that next time you drove it that crack was bigger and now doesn't put as much pressure on the drum. With the servo out put the bare pin in and see if you can feel it moving when you push the pin in by hand. None of the aussie stuff as far as i know had vette servo, it's a worthwhile upgrade.
Charlescrown
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Re: 4L60-E Problems. Help.

Post by Charlescrown »

Not my specialty area but from experience servo seals do go hard over time but usually start off with shift problems when cold improving as it warms up. The band however can break suddenly causing a problem from there on. Do these transmissions have bands? or all clutches. You need to have a good look at an application chart to narrow it down. I have a few manuals and being such a shitty day will look through and see what I can find.
Charlescrown
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Re: 4L60-E Problems. Help.

Post by Charlescrown »

It looks like a broken 2-4 band or a problem with the servo.
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Chuff
Posts: 267
Joined: Thu Dec 20, 2012 5:28 pm
Location: Melbourne

Re: 4L60-E Problems. Help.

Post by Chuff »

Charlescrown wrote:It looks like a broken 2-4 band or a problem with the servo.
Yep. I came to the same conclusions based, in part, on the same source.

I'm really hoping it's the servo, as that can hopefully be fixed with removing/dismantling/reassembling/reinstalling the transmission. :thumbup:

Otherwise it means removing/dismantling/reassembling/reinstalling the transmission. :thumbdown:
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