1. Valve Body Gasket/Seals: The most probable culprit is a leak from the valve body gasket or seals. The valve body sits atop the transmission case, and its gasket can deteriorate, allowing fluid to seep out. This fluid can then run down and appear to be coming from the linkage.
* Correction: This requires removing the valve body. Inspect the gasket carefully for damage. Replace the gasket with a new one and inspect the valve body seals while you're in there. This is a moderately advanced repair that often requires a transmission shop manual for guidance.
2. Shift Linkage Bushings/Seals: While less likely, worn or damaged bushings in the shift linkage itself *could* allow fluid to escape if they're positioned close to a leak point within the transmission. However, this usually results in more of a seep rather than a significant leak.
* Correction: Inspect the bushings for wear. If they are cracked or worn, replace them with new ones. This is a simpler repair.
3. Transmission Case Cracks: Although less common, a hairline crack in the transmission case near the linkage could be the source. This would be harder to detect.
* Correction: This requires a thorough inspection of the case for cracks, often with the transmission partially disassembled or completely removed. Repairing a cracked case can be challenging and might require welding or epoxy repair by a specialist.
4. Incorrect Reassembly: If the transmission was recently serviced, there's a small chance that something wasn't reassembled correctly (e.g., the valve body wasn't properly seated).
* Correction: Carefully double-check the assembly procedure using a shop manual.
Troubleshooting Steps:
1. Clean Everything: Thoroughly clean the transmission and surrounding area with a degreaser. This will allow you to pinpoint the exact location of the leak after it's run for a short time.
2. Observe the Leak: After cleaning, run the engine, shift the transmission through the gears, and carefully observe where the fluid is coming from. Look *above* the linkage for the source, not just where the fluid ends up.
3. Shop Manual: Get a shop manual specific to your 1973 Dodge Charger's 904 transmission. This is invaluable for understanding the transmission's construction and proper repair procedures.
Recommendation:
Unless you have significant experience working on automatic transmissions, it's strongly recommended you take your vehicle to a reputable transmission shop. Attempting these repairs without the proper knowledge and tools can lead to further damage. The cost of a professional diagnosis and repair will likely be less than the cost of a potentially more serious problem caused by an improper repair.
