Stupid 4l60e and a 2-3 flare shift, here we go again VIDEO ADDED
#21
Moderator
I've never gotten the 2-3 shift to be anywhere as firm as the 1-2 shift, even with over-sized holes in the separator plate. A local trans builder asked me if I had ever gotten a very firm 2-3 shift because he had not and wondered if it was even possible.
Also, if your shift goes below your stall speed it will also feel softer.
You really might need to log the engine rpm during the shift to see if there really is a flare.
Also, if your shift goes below your stall speed it will also feel softer.
You really might need to log the engine rpm during the shift to see if there really is a flare.
#25
Haven't been able to get back out to the car yet to see if adding some fluid will help it. Since it started flaring again the only thing I changed was going to the taller tire and I was running 2 coolers but ended up swapping to a big single cooler so I did loose some fluid there and didn't add any bc the dip stick was reading at full when warm
#27
LS1Tech Sponsor
iTrader: (25)
You will never have as quick or firm a shift on the 2-3 as the 1-2 the hydraulics and the friction assemblys and method of apply is completely different plus alot more happening hydraulically onthe 2-3 than the 1-2. Good shift yes shift like the 1-2 or as quick no. Keep us posted on logs,
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#28
You will never have as quick or firm a shift on the 2-3 as the 1-2 the hydraulics and the friction assemblys and method of apply is completely different plus alot more happening hydraulically onthe 2-3 than the 1-2. Good shift yes shift like the 1-2 or as quick no. Keep us posted on logs,
#30
Moderator
That is just one instance of a PCM causing a flare.
Has anyone heard of that ever happening again?
It is certainly good to know a PCM could cause this, but I would bet that only happens in 0.1% of cases.
(I have tried to help several people with Flares and it seems everyone finds this article.)
#32
Well after some trial and error I felt I would bring this thread from the dead. I finally figured it out guys... Now I can sleep at night! Lol, but anyways tonight when I got off work I decided to drop the pan and put new fluid in the trans mainly bc the trans had been overfilled. I had read where too much trans fluid could cause issues with line pressure. I made sure the fluid was spot on as far as where it needed to be and then added about a half quart more for safe measure and its what Performabuilt had suggested. I took the car out, got the transmission warm and did a few 2nd to 3rd gear pulls and to my surprise the flare thus far is completely gone. You can add this to the long list of culprits of reasons for getting the notorious 4l60e 2-3 shift flare.
#34
Most people would be amazed how many customers (even respectable shops) don't understand proper fluid level, and can't get it right.
It's also fairly easy to distinguish low fluid level failures when disassembling a transmission.
#36
Moderator
Thanks for "closing" the thread and glad you solved it.
Also interesting info.
I guess that if the fluid level is high enough, the various "exhaust ports" in the trans and valve body don't exhaust fully and cause problems.
Also interesting info.
I guess that if the fluid level is high enough, the various "exhaust ports" in the trans and valve body don't exhaust fully and cause problems.
#37
LS1Tech Sponsor
iTrader: (25)
To high a level you risk churning air into the system making low line pressure, To low you risk evacuating the pan again low line pressure . The 4L60E is tricky that way you should see on the dyno what being just 1/4 quart low does to the pressure gauge it goes nuts a little to much the same gauge jumps all over the place.
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#38
Moderator
To high a level you risk churning air into the system making low line pressure, To low you risk evacuating the pan again low line pressure . The 4L60E is tricky that way you should see on the dyno what being just 1/4 quart low does to the pressure gauge it goes nuts a little to much the same gauge jumps all over the place.
#39
8 Second Club
iTrader: (3)
You guys should own C5 Corvettes. Takes an hour to check the fluid level if you are a non-lift owning guy like me.
20 min to warm the trans, a good half hour to get the car up in the air to check it.
Then, you get to lay under a running car.......
It takes a pump to fill, ATF won't flow up hill.
There is no dip stick. You fill until ATF runs out the side fill in the pan.
So much fun.....
Ron
20 min to warm the trans, a good half hour to get the car up in the air to check it.
Then, you get to lay under a running car.......
It takes a pump to fill, ATF won't flow up hill.
There is no dip stick. You fill until ATF runs out the side fill in the pan.
So much fun.....
Ron