98 Passport w/ AT: drive gears failed, will shift, but no go

have scanned for trouble codes brown was probably burnt trans fluid ---either way was filter changed --if not probably clogged and or damaged -----but prognosis not good more than likely trans fried ---have evaluated by a trans shop or auto repair shop

Jorge, as richie46 recommended check trans, fluid level. At higher mileages,150,000 the automatic transmission may not shift correctly. This can be caused by the throttle position sensor out of adjustment or a shift solenoid needing to be replaced. Typically the transmission does not need to be completely overhauled.
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I don't think overheating of the engine has much to do with the transmission, either automatic or manual. If you have an automatic transmission, did you check the fluid? Sometimes low fluid stops certain gears from changing, as the torque converter doesn't have enough fluid to pressurize the servos to engage the clutches.

check your transmission fluid level. don`t over fill oil or trans fluid.
a trans is basically a hydrolic system without fluid the trans cannot turn the gears. switch to a lower get to see if it moves. if you linkage is loose or slipped the shift may be in another gear like neutral and not drive.

Make sure the trans cooler is getting a good air flow. and a trans flush is always good, and most oil change shops do it for around $89+

not enough trans fluid...... if it slips after a trans flush reuse the old fluid its got the old clutch dust in it and the clutches will grab better....

Check fluid level with engine running! Does it have or do you see fluid under,or all over the transmission?Refill if needed!

Ya sounds like the electric shift solenoid. Problem with electrical. Will not give you a warning. Will go bad in a heartbeat. You can try unhooking plug that gos into the trans and spray electrical cleaner on it. plug back in. Wiggle some wires and maybe find one loose or broken wire or connection and hope for the best. But its probably the tranny with that many miles. Go to Advance Auto Parts they usually scan your car for free for codes. Good luck

I am really sorry to deliver the bad news but the transmission has failed and wioll need to be replaced, the black fluid indicates a forward clutch pack faiure.

Unfortunately, it sounds pretty bad, good job listing the symptoms though, appreciate it. Now what I would do next is replace the oil completely (and filter if there is one). Its your last hope of saving the trans, plus you can get some valuable clues. When you drain the oil inspect it closely for metal filings/fragments, and take note of the smell too. Does it smell burnt? Is the oil discolored? Also pay attention for leaks, trans oil level doesn't usually go down unless theres a leak. It doesn't hurt to save a sample of the oil or fragments for an expert to inspect. Unfortunately, if new oil doesnt change anything, then overhaul is iminent. Hope this helps.