Novice here.

I bought a 96 f-150 v-8 auto with 39k. The trans does not pull worth donkey, despite a pulling package. It totally bogged down and would not down-shift when I hit a small hill on a hard dirt road while pulling about 3000lbs. I stopped and downshifted to 2. It revved like it was in neutral. I put it back in D (OD button turned off) and managed to get turned around. Then I tried to back it up the hill. It went about 20 feet before just revving like it was in neutral again. The tranny oil looks full and is bright red. Without the trailer, it engages with a big clunk that rocks the truck, and if I floor it, it revs way up for a second before shifting and then resuming.

I am taking it to the shop next week - got a 6 month 'drivetrain warranty', whatever that means. I think that this tranny might be a turd.

I want to pull 3-4000 pound utility \ camping trailers cross-country once in a while and get the best mileage that I can. Most of my driving is just cruising around on country roads. If there is a real problem with my current tranny, would anyone recommend that I swap to the manual 5-speed?

Thanks.