4L60 slipping when engine is warmed up

[Supercharged111]

Case in point. 96 G1500 5.0/4L60E. Bought it with 140K, trans went out at 155K. I like my transmission rebuilder, he puts the good parts in and leaves out the boy racer parts--it tends to make the trans last longer.

The everyday payload of that van is maxed out, plus I have 2-3 ft of ladders stacked on top--they act like a big sail. The TQ spends more time unlocked than locked. The van does NOT have the external cooler, only the heat exchanger in the radiator. I have 95k on the rebuild now.

How has that 4L60E performed such a miracle? I keep the fluid bright red in all 5 of my 4L60E's. To that end the best thing a guy can do for ANY auto trans is put a drain plug in it--and use it often and frequently. My light G2500 Savana has 50K on it's rebuilt 4L60E.

Pull the drain plug 3-4 or even 5 times a year and refill. Both my K1500's have the CRF deep pans on them--when I pull the drain plug 6 1/2 qts come out. The 96 has 80K on the rebuilt trans and the 97 has 164K on the original trans.

The hard part isn't keeping 4l60E's running, the hard part is convincing the idjits to change the fluid often and frequently...........

95k on a rebuild shouldn't be considered a miracle. If it wants to die, it's gonna die and there's nothing you can do about it. Keeping the fluid clean is a given to keep any trans alive. Most people driving old stuff just drive it into the ground and when it dies, they replace it with an equally cheap/old vehicle to kill with ignorance.

 

[df2x4]

95k on a rebuild shouldn't be considered a miracle.

85K more than I got out of mine!

(Once again it was probably my fault, but still, I mean damn.)

 

[Channeled 91]

here is a question from when this all started. I changed the fluid and filter on the transmission. A few days later the floor around the truck was covered in ATF. It seemed to have drained out of he tail shaft dousing or tail shaft itself. I do not know. but... could this have drained all the fluid out of the transmission and torque converter.
attached photo of puddle and video of the leak at yoke.

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[Supercharged111]

Only way for the converter to lose fluid is for the pump to push it through. This is why a mere filter change and top off aren't enough. There's another 2 gallons in the trans with most of it in the converter.

 

[alpinecrick]

95k on a rebuild shouldn't be considered a miracle.

Apparently here on the interweb it's a miracle! Especially on a van with a maxed out payload and a drag coefficient of the Mayflower.........

A lot of "rebuilds" are done on the garage floor, or by rebuilders who simply ain't doing it right, and/or installing parts that are great for stoplight to stoplight Saturday nights, but aren't much for longevity.

 

[Supercharged111]

Apparently here on the interweb it's a miracle! Especially on a van with a maxed out payload and a drag coefficient of the Mayflower.........

A lot of "rebuilds" are done on the garage floor, or by rebuilders who simply ain't doing it right, and/or installing parts that are great for stoplight to stoplight Saturday nights, but aren't much for longevity.

You're right that it is a miracle, I'm saying it shouldn't be but is because 4L60.

 

[alpinecrick]

You're right that it is a miracle, I'm saying it shouldn't be but is because 4L60.

Just keep the fluid clean, and miracles will happen.........

 

[Supercharged111]

Just keep the fluid clean, and miracles will happen.........

My fluid was cherry red when I broke the case on my 4L60. I purge every single transmission in every vehicle that I own regardless of mileage. Haven't had one magically fail after that, minus the broken case but that's apples and oranges.

 

[alpinecrick]

My fluid was cherry red when I broke the case on my 4L60. I purge every single transmission in every vehicle that I own regardless of mileage. Haven't had one magically fail after that, minus the broken case but that's apples and oranges.

And just what were you doing to break the case?!

 

[Supercharged111]

And just what were you doing to break the case?!

I think I fvcked up the tune and ran max line pressure because of how the trans acted. Looking at it though, I never determined how. That said, every time I dropped that pan there was always mud until I did a proper purge. Once I re-enabled the MAF it smoothed out big-time, but again apples and oranges as I never smoked that 3-4 clutch pack as I should have.