Transmission not shifting into 3rd...

[MannyB]

Took the denali for its yearly Mr lube visit. I drive maybe 4k miles a year.

Got the fuel filter, transmission fluid and filter changed with the usual oil/filter. Fuel filter was last changed in 2015 and doubt the Trans has ever been done.

The Trans won't shift into third gear now, it hits a random point on the speedometer and stops while revs keep increasing.

Anyone experience this issue before?

 

[Erickk120]

No 3rd or 4th gear: “3-4” clutches are worn out: Needs to be removed and rebuilt. The car is safe to drive (in 2) until you can get it fixed.

How many miles does it have?
Sounds like changing the fluid has caused it to slip,assuming its got over 150k miles.
Common 3/4 clutch problem, now you have 3 neutrals. This is a risk you take when replacing fluids on unknown vehicles, you never know if they've been maintained. Eventually though could have been 5/10/15k miles down the road the same thing would have happened, so don't lose too much sleep over it. It sucks, I think all of us 4l60e owners have gone through it at least once.

 

[MannyB]

No 3rd or 4th gear: “3-4” clutches are worn out: Needs to be removed and rebuilt. The car is safe to drive (in 2) until you can get it fixed.

How many miles does it have?
Sounds like changing the fluid has caused it to slip,assuming its got over 150k miles.
Common 3/4 clutch problem, now you have 3 neutrals. This is a risk you take when replacing fluids on unknown vehicles, you never know if they've been maintained. Eventually though could have been 5/10/15k miles down the road the same thing would have happened, so don't lose too much sleep over it. It sucks, I think all of us 4l60e owners have gone through it at least once.

182kms so 113k miles

Drove there completely fine. Never had any issues.

That's ****** if I have to rebuild because I was trying to maintain it.

 

[Erickk120]

That is interesting, 100k miles. The tranny is trying to get into 3rd and it just revs up and nothing happens correct? If so it is indeed slipping and the previous statement would still apply. I can't believe it went out at 113k though, well my first one failed at 160kish. Currently on 226k so about 66k on the current rebuild. Already replaced the pump bushings due to a leak, I abuse mine from time to time though. So it is surprising it failed so early. What did the fluid looked/looks like now?

 

[Doubeleive]

you might get lucky and have it just be a solenoid, or even a loose connection on a solenoid or the harness if they took the pan off, I would take it by a professional transmission shop and get there opinion, if I remember correctly even if the clutches were worn and slipping I don't think that would require a total rebuild

 

[SnowDrifter]

Was it doing this prior to that fluid/filter change?

 

[swathdiver]

Took the denali for its yearly Mr lube visit. I drive maybe 4k miles a year.

Got the fuel filter, transmission fluid and filter changed with the usual oil/filter. Fuel filter was last changed in 2015 and doubt the Trans has ever been done.

The Trans won't shift into third gear now, it hits a random point on the speedometer and stops while revs keep increasing.

Anyone experience this issue before?

Debris got your solenoid valve stuck. Command the valve to move with your Tech-2. Use the shop manual to run the tests that go along with the symptoms you are experiencing.

Choose your transmission shop wisely, it's very easy for them to say you need a new transmission when all that's wrong with it is some sediment got kicked up and needs clearing.

 

[Tonyrodz]

Same thing happened to my work van--4l80--changed a solenoid and the harness--fixed it. Happened right after I changed the fluid and filter in my driveway. Thought it blew too. Gotta get a scanner and check for any trans codes.

 

[Erickk120]

You can try the recommended above, It rarely happens but it can happen, also pulling the trans fuse should put you into limp mode, and only 3rd should be engaged, see what happens then.

 

[MannyB]

Solenoid is being changed right now. see what it does.

Thanks for the info bros.

Was it doing this prior to that fluid/filter change?

nope. Never had any issue with the drivetrain.

 

[89Suburban]

Urban myth strikes again!!!!

 

[SnowDrifter]

Urban myth strikes again!!!!

?

 

[MannyB]

?

 

[Doubeleive]

the myth that flushing the transmission will kill it, I wouldn't call it a myth though it's happened to a lot of people including myself, when the maintenance routine is unknown I think it happens more often with transmissions that have not been maintained on a regular basis, which is why I do mine annually regardless of mileage

 

[SnowDrifter]

the myth that flushing the transmission will kill it, I wouldn't call it a myth though it's happened to a lot of people including myself, when the maintenance routine is unknown I think it happens more often with transmissions that have not been maintained on a regular basis, which is why I do mine annually regardless of mileage

Not sure it's that it kills it as much as it exposes underlying issues such as clutch wear that an existing abrasive trans fluid would otherwise mask, and is why I make a pretty big deal about inspecting thr current condition of the fluid prior to doing any service. If it looks like shit, leave it alone and start saving for a rebuild. It'll work in the mean time, but not for long as the death note has already been signed.

That being said, in OPs case, with 113k, I'd be surprised if the clutches were genuinely shot unless he has a habit of absolutely beating the ever loving piss out of the thing since day 1.

Dropping the pan and doing the filter introduces some variables and the potential for error. Could be a busted plug, pin tension, accumulator, wrong fluid used / level, etc. Really just need to get a scan tool in there and observe commanded vs. Actual, see what's up.

Though I will say, in the state the trans is in now, be very very careful how you drive it. Trans clutches don't have a lot of thermal mass and driving the thing while it's slipping will burn them up in about 30 seconds. THEN you absolutely need a rebuild.

 

[MannyB]

They changed the Solenoid and all is well.

disaster averted.

 

[89Suburban]

They changed the Solenoid and all is well.

disaster averted.

 

[SnowDrifter]

They changed the Solenoid and all is well.

disaster averted.

Great news! That'll make you pucker for a hot minute.

We're they/you able to determine cause of failure on the old solenoid?

 

[MannyB]

Great news! That'll make you pucker for a hot minute.

We're they/you able to determine cause of failure on the old solenoid?

no idea. Never asked.