Hey guys, I just have a quick question and I hope your expertise will help me out.

I recently got a 99 F-150 4.2 and found out that the trans fluid is original... 158,000km / just shy of 100k miles.I have seen a few dozen answers saying to get a fluid change and the same saying dont touch it as it will dcause everything to blow.

The trans has done nothing really but be a city / highway driver and the odd camper haul so it makes me feel a bit better. I know the old saying "if it aint broke dont fix it" but I don't know if that applies to this situation... If you guys could help me decide what to do that would be great thanks.

Phil

 

Do a full fluid exchange in your driveway. Check your torque converter for a drain plug. It makes the job a little bit easier.

I changed my original fluid at 144k with Royal Purple, and everything is holding together 20k miles later.

The horror stories you hear come from owners that take their high-mileage transmissions to shops to get them "flushed" with a machine. Don't do that.