How can you tell if an automatic transmission is any good?

[BrianDamage]

How can you tell if an automatic transmission that has been setting up for a while is any good? the fluid is nice and red and looks new....not sure how long it's been sitting up. It's been bolted to the motor and in the truck the whole time

 

[corey6969]

The only way I know of is to actually drive the truck and feel for any really soft shifts or abnormally hard shifts or if any gears dont work at all, slippage...etc. Red fluid is a good sign but it could have just been dropped and refilled and never ran on the new fluid. I bought a 2004R from a junk yard one time that had been sitting for at least 3 years and it ran perfectly, even stood up to my Olds 455 for a while!!

 

[jt512]

flip a coin? unfortunatly with out driving it it's really tough to know for sure. clean, red fluid is a good sign but can also be a cover up for a bad tranny. pulling the pan will tell you a little more but still not a sure fire way to know what you are getting.

 

[4X4HIGH]

Unless it is your trans that worked perfectly and then just sat for a long time and you're wondering if it is still good then there is no real way of knowing. If it is your trans that was working good when parked the only thing that could go bad are some internal rubbers or if the trans got water in it.