Foam in transmission question

[RUFLYF]

Hello, I recently took my blazer on a road trip (300 miles) and noticed a lot of transmission spray on the trailer I was pulling. I checked the transmission fluid and found it to be quite foamy. It was full or a lil over full still, even after the trip. Earlier in the day before I went on the trip I had Walmart do its regular oil change, the paperwork doesnt show any tranny fluid being added. I have a feeling the spray was coming from a overflow weep hole, but havent confirmed the source of the spray yet. Anyone have and idea what would cause foamy tranny fluid?

[RUFLYF]

oh ya, my blazer is a '97 4x4...4 door

[stubbornmike]

The cause of this problem is old fluid fliuid gets burned and starts breaking down. Change your trans fliud and filter.. Having your transmission flushed would prob. be a good idea.

[quaddriver]

Tranny fluid foams when it has air whipped into it (thats why its called foam) It gets air whipped into it by fluid getting into the geartrain. You have a 4L60E tranny, which does have a vent from the top of the case.

There are two ways to get the oil into the gear train: overfill it. overheat it.

You can overfill a 4L60 by at least 2 qts b4 you hit the gear train so I suspect a combination of both.

[bduff509]

I had a Turbo 400 do the same thing to me pulling a stock car up a 5 mi. grade on I80 just before it blew. The fluid wasn't burnt or over full. If you tow much w/ a heavy load you may be looking at the same thing. Good luck.

[jkdon]

I had the same problem the fluid and filter was changed at 100k and does not seem to be overflowing.