2012 f250 superduty diesel. Needs transmission
fluid changed. I purchased the truck used with
100k and now have 140k of hauling heavy
loads.Owners manual did not come with the truck
so i don't known what oil to pour in.
Did you consider calling the dealership and just asking them? You might try and download the owners manual. I'm sure that changing the fluid wouldn't hurt and you say that you have put an additional 40,000 miles in what time period?? 140,000 miles on a 2012 vehicle is a lot of miles?
Yes a 140K on a 2012 is a lot of miles but it is a Diesel so it is not as bad as it would be for a gas fired engine. The type of fluid used will be marked on the fluid dipstick. Don't just drain and refill, change the fliters also.
I think the answer just given makes sense, yes, disel engines have longer life spans, and changing out the fluid and filters always sound advisable on any transmission.