Hard shift from 1st to 2nd and more

[tomloans]

Hello all,

I have about 210k miles on this 2003 Tahoe LT with the 5.3L engine. I have a hard shift from 1st to 2nd. There is a lot of info out there regarding this known issue that arises over time. But I am by no means understanding how these trannys work. I am going to drop the pan and when I do, I want to change solenoids as well as the accumulator and anything else you guys deem necessary. But I haven't been able to figure what is what under there. Can someone who understands this tranny give me a parts list comprehensive so I can order it all and get it done. Been staring at this for about 2 weeks and a bit confused. For instance some say to change out the accumulator, but it appears you can only by the shell and you have to but the innards separately. Is this what I should do?


In essence, I want to replace anything I can while down there so this will last another 200k miles. I have replaced the oil on this tranny 7 times since purchased so it has been taken care of well. Any help would be a treasure for me. Thank you!

 

[mattbta]

Subscribed. Followed your cylinder head work - so I know you're capable. There will be others that can give yo the details you're after.

 

[afpj]

03 Tahoe - 4l60e "lurches" on 1-2 shift

Howdy y'all, I'm back at ya again with some noob questions lol So I've recently noticed that when my transmission shifts from 1-2, there's sometimes a bit of a hiccup. It seems to be taking a while to fully engage, like a full second, and then when it does engage its very aggressive. Like it...

www.tahoeyukonforum.com

Linked thread has good info

 

[tomloans]

Subscribed. Followed your cylinder head work - so I know you're capable. There will be others that can give yo the details you're after.

Thanks. I appreciate that. It was quite a job let me tell you and no way I could have done that without guys like you on here! Much appreciated!

 

[tomloans]

@afpj , Definitely going to rebuild the accumulator as noted in this great post from @rockola1971 you pointed out ...

"A stuck 1-2 accumulator piston or broken spring will cause this exact problem. Its not at all uncommon for the spring to break in half. In fact its very common to find them broken in half when the tranny is opened up for the first time since the factory built it. Also not at all uncommon for the guide pin to wear the center hole of the piston.

Very common during a rebuild for the 1-2 accumulator to need a need a new piston, guide pin and spring. Most shops will replace it anyway if original so the tranny doesn't come back. The purpose of the 1-2 accumulator is to soften the apply of the clutch pack instead of it being harsh and fast. If any of the parts are worn or broken then it will cause the 1-2 shift to be very firm and fast. Doesn't hurt the tranny at all, just most people don't want to be snapped during the shift from 1-2."

I guess my question is, besides the rebuild of the accumulator, what else should I replace while I have the bottom off? There are a lot of arrows pointing to a bunch of solenoids. Will some of these eventually need replacing as well?

 

[rockola1971]

If you plan on keeping the vehicle for some time then I would replace the wiring harness and ALL solenoids. The separator plate will be peened from check balls so it will need replaced. Both accumulator pistons should be replaced. All bores in the valve body need closely inspected along with their valves for wear and burrs, out of round, etc. Replaced as needed.
If you need to go the cheap route then just the accumulator pistons and separator plate. Getting to solenoids is easy enough if/when they die.
You might look up on rockauto a replacement valve body and price check.

 

[tomloans]

If you plan on keeping the vehicle for some time then I would replace the wiring harness and ALL solenoids. The separator plate will be peened from check balls so it will need replaced. Both accumulator pistons should be replaced. All bores in the valve body need closely inspected along with their valves for wear and burrs, out of round, etc. Replaced as needed.
If you need to go the cheap route then just the accumulator pistons and separator plate. Getting to solenoids is easy enough if/when they die.
You might look up on rockauto a replacement valve body and price check.

Thank you!

 

[pauly1119]

The Corvette Servo is also a probable cause and is a cheap easy try. Easy to get to without taking anything apart and is worth a try. I think they are around 60 to 70 complete and is probably a 30 minute job.

 

[rockola1971]

The Corvette Servo is also a probable cause and is a cheap easy try. Easy to get to without taking anything apart and is worth a try. I think they are around 60 to 70 complete and is probably a 30 minute job.

The Corvette Servo is also a probable cause and is a cheap easy try. Easy to get to without taking anything apart and is worth a try. I think they are around 60 to 70 complete and is probably a 30 minute job.

Servo is for 2nd AND 4th gear. Its sole purpose is to hold the 2-4 band against the sunshell to make it stationary shifting into 2nd and 4th. 1-2 hard shift only can be attributed almost all the time to a busted 1-2 shift accumulator spring and/or worn piston/guide pin. The hard quick shift hurts nothing other than your neck. In fact its better for the clutches and will make them last longer but who wants to be snapped backwards in their seat everytime there is 1-2 shift. The spring is almost always busted in half on every 4L60E that gets on a bench for rebuild.

 

[tomloans]

Servo is for 2nd AND 4th gear. Its sole purpose is to hold the 2-4 band against the sunshell to make it stationary shifting into 2nd and 4th. 1-2 hard shift only can be attributed almost all the time to a busted 1-2 shift accumulator spring and/or worn piston/guide pin. The hard quick shift hurts nothing other than your neck. In fact its better for the clutches and will make them last longer but who wants to be snapped backwards in their seat everytime there is 1-2 shift. The spring is almost always busted in half on every 4L60E that gets on a bench for rebuild.

Well it is not that bad yet. So maybe we will let it go for some time until I ruptured disk in my neck. LOL But really it only happens at slow speeds. If I accelerate normally it is normal. I just didn't want to ignore it and find out the transmission was hurt by ignoring it. If there is no issues which I read elsewhere as well, going to let it go for awhile I think. I have the parts list on Rock auto ready to go though! Thank you for the great info!