Hey Scottie,
I've bought a 2004 Chevy Suburban Z71 4x4 back in 2009. It had 74,000 miles and an automatic transmission. It currently sits at 195,000 miles and I've never changed the transmission fluid. It still shifts smooth and I don't know if should start changing the fluid now? I've heard the 04 suburban we're built pretty solid. What would you do? Thanks!
Hey Scottie,
I've bought a 2004 Chevy Suburban Z71 4x4 back in 2009. It had 74,000 miles and an automatic transmission. It currently sits at 195,000 miles and I've never changed the transmission fluid. It still shifts smooth and I don't know if should start changing the fluid now? I've heard the 04 suburban we're built pretty solid. What would you do? Thanks!
Probably not, if the fluid has never been changed, leave it be. That's the wear equivalent of 4 transmission fluid changes, and Chevy vehicles have weak automatic transmissions anyways. The fluid is likely gritty, and is the only thing keeping that transmission from slipping.
that transmission is near the end of its life anyway
If you had a Japanese car like Toyota I wouldn't mind changing the Tranny fluid even with 195k miles because they don't shed clutch shavings like American Car's do and if you only do drain and fill it wouldn't hurt it. But For Chevy it is a Big No. I would not change the tranny fluid because it is too late and the only thing it is not slipping is because the friction from the dirt is what makes the transmission shifting normally. I would leave it alone. If you change the fluid you are only going to cause problems and wish you didn't change the fluid in the first place.
I've seen numerous transmission teardowns, and the Toyota clutches look identical to the American ones. Why would they shed more?
Maybe the chemistry involved in making the clutch plates is slightly different. We Americans like to make stuff as cheaply possible, lol. If it's not the chemistry, I'm not sure. The electronics aspect of GM is atrocious, obviously.
Never changing the the transmission fluid in a Toyota with 195k miles and then changing it will likely result in the tranny slipping, too. Toyota transmissions are almost bulletproof if you change the fluid consistently. I wouldn't dare do it on a Toyota with that kind of mileage and never changing fluid.
this forum is full of questions about Toyota transmissions slipping. I don't know that the difference is that huge. Without maintenance, it seems they all start going out by around 200k. Or they get the Toyota shudder.
I will give you guys a perfect example. Back when I bought 05 Camry in 2020 it had 200k miles. I don't know if the previous owner ever replaced the fluid or not and I changed the tranny fluid ( drain and refill) at 200k miles and I drove the car for 330k miles before the engine died. I changed the fluid every 30k miles. I have changed the tranny fluid at least 4 times in my ownership. The transmission never had any problems and was shifting smoothly. So based on my experience I think it's ok to change tranny fluid even at 200k miles for a Toyota, but I wouldn't do it on an American car.
and my experience with American cars is similar. Did my own flush and transmission was still shifting great at 200k. And I really rode it hard.
Hmmm ok
It also depends in how you drove the car. If it were mainly highway miles where there's not a lot of up and downshifting, that's slightly different than driving in stop and go city traffic constantly. Highway mileage is around 10% of city driving.
I was doing combined both City and highway miles.