Did it myself today. Truck has 140,000 so it is due. Not a hard job but it takes several hours to do it right. Removed the pan and found it to be very clean, almost scarey clean. Hardly any shavings on the magnet. Very little cleaning needed. This means little wear on the trans., even at 140,000 miles! Installed new filter and fluid and put it back together. Test drive and all is well!
Now I gotta do the rear-end.
Are you hauling or towing with it?
What kind of load, if any, is it working under?
I'm a hot shot driver, so it is worked hard. I haul oilfield parts, no towing. A typical load for me can be as little as 200 lbs, up to 8500 lbs. My average load is about 3500 lbs.
It's just amazing how clean the trans. was. It must be the Mercon LV fluid. Don't ever use anything else...............cheers!