Well mine blew up around 60 , 000 miles . It was then rebuilt and lasted until 100 , 000 . Then it was rebuilt and is starting to slip AGAIN at 147 , 000 . I do not treat my truck harshly , I do not do anything that woyld be more than normal wear on a transmission , the 4 l 60 e is simply weak . It is known for being extremely weak as it is BARELY , and i mean like 10 hp barely , rated for the engines it is put behind . It isnt able to hold that limit very long . The 4 l 80 e however is marvelous . My dad has a 1996 suburban with a 454 and a 4 l 80 . It has 280 , 000 miles on it without any work done on the trans other than maintinence and at least 150 k of those miles were towing a 9 k hpuse trailer . That transmission still shifts like a dream .