Mechanical Issues:
* Low Transmission Fluid: This is the first and easiest thing to check. Low fluid can cause numerous problems, including inability to shift. Check the fluid level with the engine running and warmed up. If low, add the correct type of transmission fluid specified in your owner's manual. *However, if the fluid is very dark, burnt, or smells burnt, this suggests a more serious internal problem.*
* Clogged or Damaged Transmission Filter: A clogged filter restricts fluid flow, hindering shifting. This often accompanies low fluid levels, but can also occur even with sufficient fluid. It requires a transmission service to replace.
* Worn or Damaged Clutch Packs/Bands: Inside the transmission, clutch packs and bands engage and disengage to shift gears. Wear, damage, or breakage of these components prevents proper shifting. This is a major internal problem requiring a rebuild or replacement.
* Broken Shift Linkage: The linkage connects the shift lever to the transmission internally. A broken or damaged part of this linkage can prevent the transmission from receiving the correct shifting commands. This can be relatively easy to diagnose visually.
* Internal Valve Body Problems: The valve body controls fluid flow within the transmission. Internal valves can get stuck, worn, or damaged, leading to shifting issues. This typically requires a rebuild or replacement of the valve body.
* Problems with the shift solenoids (if electronically controlled): Some 1996 Dodge transmissions might have electronic shift controls. Faulty solenoids can prevent shifting. Diagnosis requires a scan tool.
Electrical Issues (Less Likely but Possible):
* Transmission Control Module (TCM) Problems: The TCM is the computer that controls the transmission. A faulty TCM can cause a variety of shifting problems, including being stuck in first gear. Diagnosis often requires a scan tool.
* Wiring Harness Issues: Damaged or corroded wiring to the TCM or transmission solenoids can prevent proper shifting.
Troubleshooting Steps:
1. Check the transmission fluid: Level, color, and smell are crucial indicators.
2. Inspect the shift linkage: Look for any obvious damage or looseness.
3. Listen for unusual noises: Grinding, whining, or banging noises during attempts to shift indicate internal transmission problems.
4. Have the transmission scanned: A scan tool can read codes from the TCM and identify electrical issues. This is often the most efficient way to determine if a solenoid is bad or if the TCM itself is faulty.
Important Note: If the transmission fluid is dark, burnt, or smells burnt, the transmission likely needs a major repair or replacement. Driving with a severely damaged transmission can cause further, irreversible damage. It's best to have it towed to a mechanic rather than attempting to drive it further. A professional mechanic can properly diagnose the problem and recommend the best course of action, whether it's a repair, rebuild, or replacement.
