I have a 92 suburban 2500, 350 gas engine, 4l80 trans, all stock (no lift, etc.). Don't tow anything and don't push it hard. About 6 months after I bought it the tranny went out. Replaced it with GM factory rebuild that lasted about 2 years and it went out. It was replaced under warranty and then that one went out after about 2 years also. I replaced that one with a used one and it was running better than any of them for about 4 months until reverse went out. My question is, are these "disposable" or do I just have bad luck? I installed a ext. cooler supposedly to help them last longer. Is there anything else I can do or another type of trans. I can put in? I am getting really frustrated. Thanks in advance for any replies, help.

1) See the sticky at the top of the page and try to answer as many of the ??'s as possible. This will help yourself ans others to give you answers

2) I would check that the tranny cooler. Is it allowing fluid to pass through easily? To test undo the return line and find out how much oil passes through in 10 or 20 or 30 or 60 seconds. Then compare to what the trans pump is rated for. This can be found on the internet or if your really nice your local dealership. I suspect that your not getting enough oil cooling or you have several teenagers testing it out (that reminds me to not let my brother to borrow my truck Ha Ha). I suspect it since they often dont get serviced when doing a tranny swap.

Good luck.

Either you have a black cloud cast over you or you live on hell on earth where it gets hotter than a pissant than a pepper jar. check for transmission oil cooler restriction.

Check for crimped lines from the 1st time the trans was replaced, also a contaminated cooler