That's true. Usually you can just clean out the cooler useing brake cleaner and shop air, but then a new, larger cooler never hurt anything.

 

Are you sure that the "thin round thing" you are talking about isn't the magnet that picks up the metal shavings in the bottom of the pan?

 

No, I seen that thing, in the 4L60E I have, ( the magnet) its a square magnet and its stuck to the bottom of the pan, this thing was about a 1/8th of a inch thick, it looked like it broke off a band or something. its black and it was metal. it looked like it could be a spacer or something, I never seen the Inside of a trans until I took off that pan, lol. Its the closest I ever got. I could say it was about as wide as a rubberband, flat and you can tell from looking at it that it was about as round as a can of beer. Hey, I couldnt find a good trans jack but found a nice adopter for my floor jack, I can also use it to lift motor cycles and it has trans adopter, I will be droppin that sucker tomorrow, and I pick up the new one on tuesday, wish me luck! lol. I will post when Im done taken it out. Any tips before I drop that thing????? By the way, trans made it to 160,000 and engine is still a monster, checked book on truck, its still worth 6 to 7 gran so its worth 2,000 to fix it. I think if it runs good by the summer I might ad some things to it.