I recently changed my radiator on my chevy truck 1994 and now it won't go into 3ed gear.it was working fine before I changed the radiator. I don't understand why it is doing this. If any one can help me solve this I would really appreciate it.

 

if it's an automatic, there are two hoses at the bottom of your radiator that cool transmission fluid (usually, I'm not entirely sure about your truck). Are those hoses leaking or clogged?

 

No the lines are not clogged but I just noticed that my radiator is full of oil again. This is why I change it in the first place. I thought the radiator was cracked. I've checked under my oil cap to see if it was yellow and it not.so if my heads ain't cracked and the gasket is still good. How would oil get inside my radiator. I real don't understand. Any ideas.

 

okay, so pull out your dipsticks (motor oil and transmission)
is there any coolant on either of those? It sounds like maybe your transmission fluid is mixing with your coolant.