Probably a worn out clutch disc.
If the clutch is not slipping, I would say the transmission is fine, the engine may be the reason for the lack of power.
Its a hydraulic operated clutch, so its auto adjusting. No manual adjustment. If the clutch is slipping, you need a new clutch plate.
If you accelerate and the transmission shifts to a lower gear of the overdrive disengages the RPMs will increase. If the vehicle has a manual transmission a slipping clutch will cause the RPMs to increase if the clutch is defective.
On the 1996 Ranger the manual shows to lift the clutch pedal every 5,000 miles to adjust the hydraulic clutch , I don't know if yours is the same
The clutch slave cylinder for a hydraulic clutch is inside the manual transmission bellhousing
It's probably a slipping clutch.
If the car is a manual and you are riding or slipping the clutch it could be that. Otherwise if you have been real hard on the brakes lately they can create quite a smell aswell.
Clutch slip is unavoidable. Its a part of driving a manual car, and is required in techniques such as moving off from a standing start. It happens at the clutch's biting point.
On a 1996 Ranger the manual shows to lift the clutch pedal every 5000 miles to adjust the hydraulic clutch - I have no idea if your's is the same
www.helminc.com You can find a shop manual for a lot of vehicles.
Low transmission fluid Overheated fluid, too low capacity or a blown tranny If it is a manual, you might wanna replace the clutch.
sounds like that would be your clutch wearing out