Is it safe to change transmission fluid on a high mileage car?
Changing transmission fluid on a high-mileage vehicle with an unknown history feels like a gamble that could cause a currently functional car to fail. Conflicting advice from mechanics makes drivers nervous to attempt the service, risking total loss of transportation if the transmission slips or fails afterward.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1leaving the old fluid alone and continuing to drive the vehicle
- 2checking the dipstick fluid color and smell independently before deciding
- 3Checking the color and smell of the transmission fluid
- 4Doing a drain and fill instead of a flush
- 5Replacing the filter along with the fluid
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“I'm guessing my aunt did change it when she was using it around 30k or 50k miles but the car now has 150k miles and I don't know if it's too late for a change.”source ↗
“I’m very nervous to even try because it feels like a gamble that might leave me out a car that is currently totally functional.”source ↗
“My story has is that I have a 2016 Acura tlx. Same story as you. Roughly the same mileage but mine has no dipstick.”source ↗
“Ok but I'm scared of slipping. Because I keep hearing everyone say to not change transmission oil on high mileage cars”source ↗
“This is something I've heard too.”source ↗
Where this came up
People with this problem also raised
- 7Should I change my transmission fluid at 60k miles?
- 2Should I trust extended oil change intervals or stick to 5,000 miles?
- 3Why do you have to remove the subframe to change the transmission filter?
- 2Manual transmission still making noise after fluid top off
- 9How to tell if brake pads and rotors actually need replacing
- 3Finding individual brake parts for an older car