rebuilding tranny
If this were my Explorer, I would probably say, "yes, it is worth getting the transmission rebuilt." This assumes the body isn't rusted all to heck, and that the frame isn't bent. Basically, the way I look at this question goes something like this:
option A) To repair existing vehicle, I will pay $2500 give or take to repair existing transmission. After repair, I will drive home in a vehicle with a known history and a known good transmission (at least as good as an A4LD can get). Kind of a gamble, because I don't know when the next major repair will come along.
option B) Sell vehicle as is (probably only get a few hundred dollars if lucky), put up ~$4000 out of pocket to get another '94 Explorer. Won't know history or have any other idea as to how the vehicle has been treated. More of a gamble, because, not knowing the history, it is harder to predict when the next major repair will occur.
option c) Sell vehicle as is (~$x00) and buy something newer with fewer miles. Out of pocket costs for this option can vary from ~$4000 for an older/higher mileage choice, to upwards of $50,000 for the latest greatest luxury SUV. Risk of future mechanical failure in this category varies widely, but is roughly a function of cost. At the lower end of the price range you will get an older/higher mileage vehicle. At the upper end you will get a newer vehicle with fewer miles.
A warranty can offset some of the risk. At the lower end, the warranty will add to the out of pocket cost. At the upper end, the warranty may be included in the purchase price. Depending on the specifics of the warranty, there willl be exclusions, limitations, and even deductibles, so a warranty is not a guarantee that you won't have to pay for a repair, just reduces the risk.
Whenever I've analyzed this kind of situation for myself, I almost always choose option A. I can't choose for you, though.



