Silverado transmission flush gone wrong...

I have a 2001 Silverado 1500 with the 5.3. It has about 178k miles. I've had it for almost a year now. I decided that I'd do a trans flush and replace the filter. Bought Dex VI from NAPA and a filter kit and got to it.

Everything went smoothly. I did not wind up replacing the cup that the filter inserts to. It wasn't budging and I was tired so I left it alone. The trans oil was rather clean. It had definitely been serviced before.

Started driving it the next day and noticed a few things: - at steady throttle, the revs would hunt about 100-200 rpm.
- at full throttle shifting 2-3 at around 70ish MPH, the trans would flair a bit and eventually / slowly shift to 3rd gear. - after heavy braking, getting back on the throttle, the truck didn't want to accelerate

Not sure what I could have screwed up. Anyone got any ideas?

Thanks.

Now that you've driven it, have you re-checked the fluid level? Seems like it may be slipping and that's the first thing I check when the fluid is known good. There are a couple knowledgeable people here, they can give good pointers.

That. The fluid pickup is usually at the rear. Transmission not working after braking is generally a sign that the fluid is extremely low. A 4L60 generally needs five quarts after dropping the pan.

Checking fluid level can be problematic when the dipstick is long and tortuous. You have to ignore the fluid clinging all over the stick and just look for the "heavy" line. I had a Powerstroke last week that was seven quarts low on fluid. Add two quarts, stick had light oil on it. Add two more quarts, stick had oil on it but still no "heavy" line. Add two MORE quarts, I could finally see a heavy line. Drive truck, stick was dry again.

Edit: It's possible you nicked the filter O-ring setup when trying to remove it but that doesn't fit the low fluid M.O. Did you double check the filter to make sure it was the same profile as the old one? I'm remembering that there are a bunch of different shapes and depths depending on which pan the transmission has.

Looks like it was low on oil. Wound up adding 3 additional quarts.

Turns out you need to check the level with the trans oil at operating temps and WITH the engine running. Didn't know that. Thought you could check it cold and warmed up but didn't know you had to check with the engine running. Sigh...

Hopefully, my ignorance didn't cost me a trans. Anyone think / know what damage I might have caused running it 3 quarts low?

Thanks.

Best not to know. Just drive it. If it's a problem, you'll know. If it drives fine, you dodged a bullet - enjoy it, and sleep well tonight.

amg_rx7 wrote: Looks like it was low on oil. Wound up adding 3 additional quarts. Turns out you need to check the level with the trans oil at operating temps and WITH the engine running. Didn't know that. Thought you could check it cold and warmed up but didn't know you had to check with the engine running. Sigh... Hopefully, my ignorance didn't cost me a trans. Anyone think / know what damage I might have caused running it 3 quarts low? Thanks.

While your little road trip with low fluid certainly wasn't good for it if it's working fine now that it's topped off I wouldn't worry about it.

SkinnyG wrote: Best not to know. Just drive it. If it's a problem, you'll know. If it drives fine, you dodged a bullet - enjoy it, and sleep well tonight.

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Fluid is checked engine idling, ideally hot (trans fluid temp ~180F), immediately after pulling the shifter down to low and slowly (so it goes into each gear) clicking it back up to park.