1-2 shift accumulator
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1-2 shift accumulator Ok.. I don't own an ls1 Anymore but when I did I used this forum fora lot of information.. I have a 2wd 4.8 2007 silverado.. 4l60e.. I know there are a lot more technically inclined guys here than on the silverado forums..
I'm have a very a hard 1-2 shift so I took pan off to inspect and when I took 1-2 accumulator housing off I noticed there was only one spring... Most I've seen has had 2 springs and I have no idea if this tranny had been worked on.. Do any of the 4l60e come with only one spring here or is this some botched work?Only symptoms are hard shift From park to drive and 1-2.. Intermittently..Any ideas?Fluid is nice and pinkMetal was on magnet Truck has 117xxxI left battery cable off to try to reset shift memory..Checked for codes only p0171 and p0174 more than likely vacuum leak..
I'm not sure about your specific model/year, but yes, some 4L60E transmissions only use an inner spring. Is the piston cracked or really loose in the bore? Is the pin bore worn? Your accumulator should use a composite piston, and they are known to develop cracks and/or wear down in the pin bore area.
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I'm sure it's not missing the spring bc I don't feel like anybody had been inside the tranny.. It's 1117xxx miles and has been taken care of..
The piston seems to be in good shape.. It was tight in the bore and hard to get out.. No cracks..seal is fine. I'm not sure what to check next?What would you recommend?I'm good at figuring stuff out I just need some direction
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I just bought the truck so it's hard to say.. I can't find out either bc I bought from a lot and they say they bought it from a sale.. But it doesn't do it all the time.. If it shifts hard into drive.. Its going to shift hard into second.. That's one thing I've noticed
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While I have the panoff should I order and replace solenoids just in case? I really hate to put this new filter and all this fluid in just to have the same thing going on.. What would it mean if it shifts hard or not hard from park to 3? And it wasn't doing it all the time before I took pan off..
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Yea I thought about the lean codes too... The forward accumulator looks fine.. The pin bore don't seem to be worn.. I'd put a picture up but it keeps saying admin has to approve first.. The piston did have a small scuff on it. But no cracks.. Guess I'll put it back together and fix the lean codes and go from there.. It was some metal shavings on the magnet in pan but I can't upload picture..
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Harsh shifts are often caused by the PCM commanding high pressure due to codes, including engine codes.
As Jay says, you should be checking the trans line pressure before proceeding.
And as Mr Bond says, you should fix codes before disassembling the transmission.
And yes, I have heard of other 4L60E having a single spring in the 1-2 accumulator; I think that the 2nd spring firms up the shifts, meaning your trans was built for soft shifts.
As Jay says, you should be checking the trans line pressure before proceeding.
And as Mr Bond says, you should fix codes before disassembling the transmission.
And yes, I have heard of other 4L60E having a single spring in the 1-2 accumulator; I think that the 2nd spring firms up the shifts, meaning your trans was built for soft shifts.
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Well... I got it back together and it shifts hard still... I think it even shifted hard from 2-3 a couple times.. Still not all the time.. If I go from drive to park then immediately back to 3 from drive it shifts hard.. But if I let the rpm go down when I shift to park, it shifts ok..
As for the lean codes.. I've checked for vacuum leaks found none.. Going to clean maf and see if that helps.. Wish I had a scanner. Any ideas?
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Ease up man, I got a bad case of a.d.d.. I plan on checking the pressure I'm having trouble finding a gauge I can use so I decided to test the maf . I guess the answer that would've been good was that if I had a good multimeter I can test maf with it.. I thought I had to have a scanner, I just assumed but then I looked it up. What's caused all the confusion for me is I just found out I have two more codes I didn't know I had.. For one none of my indication lamps that should be on with these codes are not illuminated.. I found my code reader as I have two codes that AutoZone didn't mention to me as he was offering me fuel treatment.. A c0561 and c0899. Almond with p0174 and p0171. So this is pushing me more in the direction of not a tranny problem. Its in protect mode I would imagine. I've read some posts that say they had similar codes with 1-2 bang and maf was the culprit.. I need to test and clean maf , and test voltages at modules bc battery and charging system is good. Maf would explain all the codes and symptoms though so I'll start there.. I do appreciate the replies And help. I will update when I get this sorted out for someone else that may run into a similar situation.
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If its a 07-08 model check or change the TCM..once they go bad they send max line pressure to the transmission and that causes the hard shifts..i see that problem atleast 2-3 times a month..also all 07+ 4l60s come with 1 small spring in the 1-2 accumalator
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Well.. I found my issue.... Vacuum leak.. Couldn't find it for anything.. So I made a smoke machine today and found it.. It was a little nipple on the side of the intake !manifold.. Thanks for all the replies.. I got to buy a scanner.. If anyone wants to see the smoke machine I made I'm gonna post a link to the video on you tube..
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https://youtu.be/d1vFtv7uIa0
That's the link to the video of the smoke machine. It's bad quality but whatever.. And yea, it was a very harsh shift.. I've had a tps cause harsh shifts and even loose battery cables, but didn't really think it was gonna be my problem this time but sure enough..
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Thank you for sharing the Video On youtube! I have an 07 4.8 Silverado with the same exact symptoms you were experiencing.. Hard Shift from Park to Drive as well as the Bang 1-2 Shift and it is intermittent. So, question is, once you found and fixed the leak, did the symptoms you were experiencing completely go away? I am just trying to figure out my same problem. I have no codes and no CEL..
@jdeaton011989
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https://youtu.be/d1vFtv7uIa0
That's the link to the video of the smoke machine. It's bad quality but whatever.. And yea, it was a very harsh shift.. I've had a tps cause harsh shifts and even loose battery cables, but didn't really think it was gonna be my problem this time but sure enough..
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[QUOTE=Chefz;20315485]Thank you for sharing the Video On youtube! I have an 07 4.8 Silverado with the same exact symptoms you were experiencing.. Hard Shift from Park to Drive as well as the Bang 1-2 Shift and it is intermittent. So, question is, once you found and fixed the leak, did the symptoms you were experiencing completely go away? I am just trying to figure out my same problem. I have no codes and no CEL..
Yes all of my symptoms went away... i know you say no cel or codes but did you check for codes?
Yes all of my symptoms went away... i know you say no cel or codes but did you check for codes?