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My “new” truck runs really good. But, one thing I question on it, is it’s transmission. it’s RWD. It takes off good, but When shifting into 2nd, it seems to lurch slightly or jump. It won’t shoot the RPM’s up though. It will sometimes do the same thing when shifting into 3rd. None of this happens all the time, but a little over half the time it cycle’s through on take off. other times I won’t even feel it shift. it has 111,000 miles on it. Has 108,000 when I got it. Should I be concerned? Anything I should know about these trucks? I had the “03 Avalanche z71 with the 5.3 but it was a 4×4.
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any engine light or codes?
Typically from what i have experienced is hard shifts are caused buy faulty pressure control solenoids in transmissions, but we should do some diagnosing first, see if you can pull any codes or history codes…
If you don’t have a transmission pressure gauge I’d recommend taking it to someone. The gauges themselves are only around 60. But only if you want to spend that money.
Do you have a 4L60 or 4L80 transmission?…The 4L60 has a 16 bolt oil pan and the 4L80 has a 17 bolt oil pan.
Yes I agree one of the diagnostic steps would be checking transmission line pressure with a gauge or a scan tool when the problem happens. But always do the transmission diagnosis steps like Eric has in his videos.
I replaced many valve bodies and spacer plates with the issue you’re having. I was told The Electronic Pressure Control valve bore wears and causes steps in the valve body bore which maybe is causing the Electronic Pressure Control valve to hang up intermittently. At a Dealer we were not allowed to do valve body work so I really did not know the root cause.
I was told there are aftermarket kits to repair that problem…but an transmission technician will have to fill you in on that..
Another thing; check TPS for smooth electrical response to the PCM
Okay, I have not yet watched the video. I’ve been busy. If I don’t get this checked out, will anything happen? i’m good with engines and heavy duty truck manual transmissions, but not automatics. Too much complication for me. I will check to see what transmission i have later. i’ll back to you as soon as possible.
brian98redskins wrote: If I don’t get this checked out, will anything happen?
That’s hard to say without me physically checking the truck. I don’t like hard shifts, but many Technicians will disagree with me on that. Maybe to be on the safe side I would take it to a good transmission shop and get their opinion.
One thing I would do is change the transmission fluid and filter if it hasn’t been changed, but only do it if you don’t have to do any transmission repair…(don’t change twice)…waste of money…
Smell the fluid. See if it smells burnt. Could be the epc. I had a similar issue on my 4l60 before it’s rebuild. It was the accumulator piston getting stuck. I went with billet servo and accumulators. But that’s the expensive solution. Could also be check balls getting stuck on the spacer plate. I had that problem to. It seems common with the steel check balls. But I think yours has the non metallic ones.
So I tested the transmission by engaging the emergency parking brake and shifting through and flooring the gas for a second or two. The truck didn’t exceed 1500 RPMs. Ran perfect the rest of the weekend. I smelled the transmission fluid and it smelled fine. It was at proper level. But then the last few days the problem has been re occurring. It isn’t a lurch more as I just feel the truck go into gear. Like it just takes a second longer it seems fine. I hope it was just a stuck solenoid. Don’t know what to do now.
I bet at some point if the trans is a 4l60e it’s been rebuilt and maybe someone decided to put a shift kit into it. MY transmission with light up the tires going into second when past 1/2 throttle accelerating. It shifts really hard and fast. It’ll drop from 3600 to 2000 and hit hard. Not that its bad for my transmission. 5 pinion planetaries are so much stronger than those garbage 3 pinions.
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