Bubbles on automatic transmission fluid dipstick

Alex05

TJ Enthusiast
Original poster
Joined
Jun 18, 2020
Messages
136
Location
Madison, WI
Hey all, yesterday I decided to take a peek at the fluid in my '05 LJ auto. I examined the dipstick twice, and both times it came back with small bubbles most of the way up the fluid level indicator area. The bubbles did not look like foam, rather they were trapped in the fluid on the stick.
Trans was at operating temp and motor was running, but I may not have let it sit still for 60s.
I do not think that the fluid looked burnt up, or like a pink milkshake. The fluid level was at the normal indicator mark. It was darker but not burnt. However, automatics and their fluid level & quality getting out of whack is something that can obviously ruin a wallet in a hurry.
Is it common to see bubbles on a transmission dipstick? Is this worth some time with professional eyes? Overall it seems to be shifting normally, but it's always difficult to tell with these 42RLE's, since they really don't shift all that quickly in the first place. Transmission fluid is likely original from 2005, and the vehicle has 31k on the odometer.
 
Drop the transmission pan, do a visual check of what's in the bottom of the pan, and on the magnet. If it looks good, add a new Mopar filter and ATF+4 fluid. At that mileage you shouldn't have any issues.
 
Drop the transmission pan, do a visual check of what's in the bottom of the pan, and on the magnet. If it looks good, add a new Mopar filter and ATF+4 fluid. At that mileage you shouldn't have any issues.

Unfortunately I likely won't be able to drop the pan anytime soon. Ultimately I'm wondering if bubbles on the dipstick is cause for expeditious concern.
 
While the engine is RUNNING and the transmission in Park or Neutral check the ATF level with the transmission's dipstick. If it's not all the way to the full hot line add more ATF+4 until it is. It's better for an automatic transmission to be slightly overfilled than underfilled. No, you can't check the ATF level even right after the engine was shut off, the engine has to be running to get the actual level.