Walked into a shop in Oakland and saw a 1985 F250 with 400k miles still on the original transmission

The owner said he just changes the fluid every 30k and never had a single issue. Has anyone else seen trucks from that era go that long without a rebuild?

4 comments

4 Comments

ward.anna13d agoMost Upvoted

My neighbor had an '87 F250 with the 6.9 diesel and it went over 430,000 miles on the factory transmission before he sold it. He was religious about the fluid changes though, every 25,000 miles like clockwork. The body was pretty well rusted out by then but that old drivetrain just kept chugging along. I had an '86 F150 myself with the 300 straight six and it finally needed a rebuild at around 320,000, but that was because I towed a heavy boat with it every weekend for years. Those old Fords from the 80s really did have something special in their transmissions.

paul_ramirez13d agoMost Upvoted

Fluid changes are like brushing your teeth. Nobody does it until something breaks.

gavin_kim13d ago

...you're right about those 300 straight sixes being tough as nails, but I gotta call something out with the 6.9 diesel from your story. Those IH built diesels were actually pretty notorious for having transmission issues if you didn't stay on top of the fluid religiously. The C6 in the gas trucks was way more bulletproof than the ones paired with the 6.9. I've seen a bunch of those diesel trucks eat the factory trans before 200k if the owner slipped even once on maintenance. The real unsung hero from that era is the AOD in the lighter duty trucks, people rag on them but a well maintained one can go the distance too.

davis.olivia13d ago

Being religious about fluid changes" is the whole secret right there. Most people just don't do it.