1500
I know of 4 separate Silverado's of that era whose auto trannies were done for at around 100k to 125k. One was privately owned and the other three were fleet vehicles. It's the nature of the beast. IMHO that local mechanic wasn't the cause of your brother's tranny failure.
He said the transmission was perfectly fine before it went to him . That said he didn't even bother confronting either him or the dealer .
