1. Clutch Issues: This is the most likely culprit.
* Clutch Master Cylinder/Slave Cylinder Failure: These hydraulic components engage and disengage the clutch. A leak or failure means the clutch isn't fully disengaging, preventing shifting. Check for leaks around the master cylinder (under the dash) and the slave cylinder (near the transmission). If fluid is low or leaking, this is a strong suspect.
* Clutch Cable (if cable-operated): If your Ranger uses a cable instead of hydraulics, the cable could be broken, stretched, or improperly adjusted. Inspect the cable for damage and check its adjustment.
* Clutch Disc/Pressure Plate Problems: The clutch disc itself might be worn out, warped, or broken. The pressure plate, which pushes the disc against the flywheel, could also be faulty. This usually involves more gradual symptoms before complete failure, but it's possible for a sudden catastrophic failure to occur.
2. Transmission Problems (Less Likely, but More Serious):
* Internal Transmission Failure: This is the worst-case scenario. Something inside the transmission might have broken—gears, bearings, or synchronizers. This often involves noises before complete failure, but not always.
* Shift Linkage Problems: The linkage connecting the shifter to the transmission could be bent, broken, or disconnected. Inspect the linkage for any obvious damage.
* Transmission Fluid: Check the transmission fluid level. Low fluid could cause shifting problems. However, if the fluid is low it might not be the *only* cause (a leak might indicate more serious issues)
Troubleshooting Steps:
1. Check the Clutch: With the engine off, try shifting through the gears. If you can shift easily with the engine off, the clutch system is likely the problem.
2. Check the Clutch Fluid (Hydraulic Clutch): Locate the clutch master cylinder reservoir (often near the brake master cylinder) and check the fluid level. Low fluid or leaks strongly suggest a hydraulic problem.
3. Inspect the Clutch Cable (if applicable): Check the cable for fraying, stretching, or disconnection. If adjustable, check and adjust its tension according to the owner's manual.
4. Check Transmission Fluid: Check the level and condition of the transmission fluid. Low fluid or very dark, burnt-smelling fluid point to problems. Refer to your owner's manual for the correct location and procedure.
5. Check the Shift Linkage: Visually inspect the shift linkage for damage or disconnections.
What to do next:
* If you find low fluid or leaks: You'll likely need to repair or replace the master or slave cylinder.
* If the clutch cable is the issue: Repair or replace it.
* If the linkage is broken: Repair or replace the linkage.
* If the transmission fluid is low or contaminated: Add fluid if it's low, but consider a professional inspection as this could indicate a more serious problem.
Warning: If you suspect internal transmission damage, avoid driving the truck until you have it professionally diagnosed. Further damage could occur, leading to a more expensive repair.
It's highly recommended to take your Ranger to a qualified mechanic for a proper diagnosis if you're not comfortable working on vehicles yourself. They'll have the tools and expertise to determine the exact cause and provide the necessary repair.
