Ford 8F35 Transaxle Fluid Change at 150,000 miles? What's The Consensus?

[anthonym6]

From the owners manual. Severe service is 30k miles for the transmission fluid. My initial drain/fill was at 5k miles and will be again around 15k miles. It is cheap and easy to do and since I am towing a trailer around 3500lbs I figured it can't hurt.

What Are Considered Severe Driving Conditions - A vehicle that is driven for short trips of less than 5–10 mi (8–16 km), driving in temperatures well below or above average, driving in any dusty conditions, idling more than recommended such as in traffic, and driving with a heavy load or while towing a load are considered severe driving conditions. If the vehicle is driven in any of these conditions, follow the severe service maintenance items listed in the scheduled maintenance chart.

Also here is the fill/level check procedure from the service manual.

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[dalola]

From the owners manual. Severe service is 30k miles for the transmission fluid. My initial drain/fill was at 5k miles and will be again around 15k miles. It is cheap and easy to do and since I am towing a trailer around 3500lbs I figured it can't hurt.

What Are Considered Severe Driving Conditions - A vehicle that is driven for short trips of less than 5–10 mi (8–16 km), driving in temperatures well below or above average, driving in any dusty conditions, idling more than recommended such as in traffic, and driving with a heavy load or while towing a load are considered severe driving conditions. If the vehicle is driven in any of these conditions, follow the severe service maintenance items listed in the scheduled maintenance chart.

Also here is the fill/level check procedure from the service manual.

Solid advice. Most people fall into the "severe" category, they just don't know it....

 

[Darryl]

Did your previous vehicle have a 6f35 or an 8f35? They're not well regarded or known to be reliable...

6f35 is a bit fragile if the fluid isn't changed a bit more often than recommended. But the 8f35 seems to be significantly less troublesome. Id probably change the fluid at 60-70,000 unless I'm towing regularly. No way I'd be changing fluid at 15-30k under normal conditions. You can tell who has been driving for many years back when transmissions used old fashioned fluids and required 30,000 mile fluid changes in order to last even 100, 000 miles. Fluids and transmissions have advanced by leaps and bounds since then. And the transmissions that have issues seem to have mechanical weaknesses that the fluid doesn't affect. But if the 15-30,000 mile fluid changes helps you sleep at night, go ahead. Change away. It can't hurt.

 

[MakinDoForNow]

6f35 is a bit fragile if the fluid isn't changed a bit more often than recommended. But the 8f35 seems to be significantly less troublesome. Id probably change the fluid at 60-70,000 unless I'm towing regularly. No way I'd be changing fluid at 15-30k under normal conditions. You can tell who has been driving for many years back when transmissions used old fashioned fluids and required 30,000 mile fluid changes in order to last even 100, 000 miles. Fluids and transmissions have advanced by leaps and bounds since then. And the transmissions that have issues seem to have mechanical weaknesses that the fluid doesn't affect. But if the 15-30,000 mile fluid changes helps you sleep at night, go ahead. Change away. It can't hurt.

Maybe to help those sleep at night or to at least consider changing trans fluid for more severe usage consider adding 10k-12k-?k miles to a trans milage change tally every time the engine change oil light comes on whether it happens at 6k-8k-10k-?k. Change trans when the tally figure reaches the recommended change milage.

 

[Darryl]

Maybe to help those sleep at night or to at least consider changing trans fluid for more severe usage consider adding 10k-12k-?k miles to a trans milage change tally every time the engine change oil light comes on whether it happens at 6k-8k-10k-?k. Change trans when the tally figure reaches the recommended change milage.

I guess that will work. Oil change + x number of miles = fluid change.

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