How much damage was likely done?

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I bought a used Chevy Silverado (5.3) almost a year ago, just after the great Harvey flood. It had 145K miles at that time. I checked the vehicle over pretty good when I bought it, and I remember seeing nice red Trans fluid on the dipstick then. I have since driven about 15,000 miles, and I checked the fluid again this week and found the fluid level almost 2 inches above the crosshatch mark. I don't know how I missed the overfill earlier, but I suppose I did. I took it to an independent shop and they did a BG flush, and the fluid is now new, and at the correct level. The truck has never exhibited any trans symptoms. Shifts have always been correct. The fluid was still red at the time of change. My question is, all things considered, how much damage (if any) was done? Should I worry much? Thanks.
 
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Was the trans at operating temp and the truck on a level surface when you checked it both times?
 
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The problem with overfilling is that the ATF will get up into the gears and air bubbles will be created, then the air mixed with fluid will cause slippage. I doubt if 2 inches overfilled would cause any trouble at all.
 
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Really to full and it would be blowing fluid out the breather. If that never happened, no big deal smile
 
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Originally Posted By: gfh77665
...... and I checked the fluid again this week and found the fluid level almost 2 inches above the crosshatch mark...... ...... The fluid was still red at the time of change. My question is, all things considered, how much damage (if any) was done? Should I worry much? Thanks.
No damage. Move on.
 
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Originally Posted By: rooflessVW
I'd say that if no drivability concerns have manifested, you're probably fine.
+1 Probably nothing. It sounds like it was possibly filled to the full/Hot mark when cold. To move it up the stick that amount doesn't necessarily translate to a whole lot in the pan. I wouldn't loose any sleep over it.
 
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In line with what Trav just said: So much fuss was made over checking the fluid in my auto I got the bug to check it several times during a day of local driving whenever I did a drain & fill. I'd be careful in the first place and have done a few D&F's over the years. I'd always find level spots to park and follow the method. The fluid's level would dance about all day long. I concluded the key was to let the car be still THEN do the gear range row (P to L to P SLOWLY then check level within 20 seconds). You maybe got a false level reading
 
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Originally Posted By: OneEyeJack
If it's not broken don't fix it.
Yep . In any case , I would not worry about it . Water under the bridge . Worrying will not improve anything . If you wish to do methinks , start putting $$$ back to pay for a transmission job . If it does not go out , you are that much ahead .
 
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Originally Posted By: TheLoneRanger
The problem with overfilling is that the ATF will get up into the gears and air bubbles will be created, then the air mixed with fluid will cause slippage. I doubt if 2 inches overfilled would cause any trouble at all.
I agree. I think no harm done.
 
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Trans fulid expands A LOT when heated. My Nissan goes form barely on the stick tip Cold and idling to an inch above the full >HOT 1/2 inch change on a moderated sized pan . So it may have just been a modest temp difference at the two times you checked it. Try it again to verify Do a 10 min commute then a 1 hour hard commute and check after each and record how it reads each instance. I'm sensitive to this as my Nissan is all over the place on DS reading without a trans oil temp monitor involved.
 
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My dad drove 3 qts low for 60+k on a 3T40. No issues at all. It didn't burn up even when the fluid would slosh away from the pickup and cause it to slip (how I found out). Just make sure there is no active leak, and get it to level.
 
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