Tranny woes...help appreciated

[ajs67donzi]

At medium speed, maybe between 30 and 40 mph, my transmission seems to bump back and forth, seemingly trying to decide what gear to be in. It is definitely a new problem and, although slight, it is noticeable to me.

 

A month prior to this I had the fluid sucked out and replaced with new, at an oil change place, and at the same time I had them add half a quart of LubeGuard Red. It is the second flush I've had done, one at 90k when bought the truck, and then this one at about 125k.

 

After driving to Florida I checked the level, and it read high, so I had a shop suck some out. It is still reading slightly high, but the guy said it was all he could reach, and it should be fine. It was a week or so after this that the problem started.

 

Could an overfilled fluid amount cause this issue? Am I in for a significant transmission repair crisis?

Oh...woe is me!

Edited November 14, 2021 by ajs67donzi

[mikeyk101]

6 speed or 8 speed? At was the fluid checked at operating temperature or after it had cooled down?

[ajs67donzi]

6-speed. Level checked at both cold and hot temps, and it is still high.

 

Doing some reading I see that one of the symptoms of overfilling is "erratic" shifting, which is what I believe I have. It doesn't look like any major damage is done, so that is (hopefully!) good news.

 

I'll be taking it in tomorrow to siphon out some more fluid...and will be keeping my fingers crossed.

[ajs67donzi]

Here is how the dipstick reads hot...it's almost up to the bend in the stick.

Captain Obvious says that is too much fluid.

 

[ajs67donzi]

Update: Fluid level is fine. Dipstick was read while engine was off, instead of while running. Duh.

A consult with a transmission shop says he sees several of these per month, with metal shavings accumulating and interfering with the torque converter, clutch, and pump. He opines that it is a design defect, and my initial research sees several class action lawsuits...but, as usual, not enough for GM to concede culpability.

 

Next he will be test-driving it, checking the filter, and doing a scan.

Hopefully it won't be a worst-case scenario!

Edited November 15, 2021 by ajs67donzi

[ajs67donzi]

Lots of metal shavings from the torque converter were found in the transmission pan.

Diagnosis...grave.

Treatment plan...transmission rebuild.

Cost...more than I'd like, but way less than a dealership.