Transmission Filter Kit Guide for the 1966-1968 Jeep CJ6A
Keep your classic Jeep's automatic transmission shifting smoothly with the right filter kit.
- Your 1966-1968 CJ6A with an automatic transmission uses the GM TH400, which determines the correct filter kit.
- Symptoms like slipping gears, delayed shifting, or a burning smell point to a clogged filter and potential transmission damage.
- Aftermarket brands like Wix are a reliable and readily available choice for this application.
- Regularly changing the transmission fluid and filter is the most effective way to ensure the longevity of this classic transmission.
Identifying Your Transmission
Before buying parts, it's important to know that if your 1966-1968 CJ6A has an automatic transmission, it is the General Motors Turbo Hydra-Matic 400, commonly known as the TH400. This was a heavy-duty transmission used in many vehicles, which is good news for finding reliable aftermarket parts. Manual transmission models do not use this kit.
Symptoms of a Clogged Transmission Filter
A dirty or clogged filter restricts fluid flow, which can lead to serious problems. If you experience any of these symptoms, you should inspect your filter and fluid immediately.
- Delayed or Rough Shifting: The transmission may hesitate or jerk when shifting gears because of low hydraulic pressure.
- Transmission Slipping: You might feel the engine rev, but the Jeep doesn't accelerate as it should, as if it's momentarily in neutral.
- Whining or Rattling Noises: Strange noises, especially when in neutral or while shifting, can be caused by fluid starvation or contaminants circulating in the system.
- Burning Smell: A lack of lubrication from a clogged filter can cause the transmission to overheat, burning the fluid and creating a distinct smell.
- Fluid Leaks: While not always caused by the filter, a clogged filter can increase pressure and heat, leading to seal and gasket failure.
Check Your Fluid
Regularly check your transmission fluid. It should be reddish and translucent. If it's dark brown, black, or smells burnt, it's a clear sign of overheating and contamination. You should change the fluid and filter immediately.
Choosing the Right Aftermarket Filter Kit
For a vehicle of this age, finding New Old Stock (NOS) or OEM parts is nearly impossible. Aftermarket is the standard and most practical choice. The key is to choose a quality brand.
Brand Focus: Wix
Wix is a well-regarded brand in the filtration market and a reliable choice for your CJ6A's TH400 transmission. Their kits are known to fit well and provide protection that meets or exceeds original standards. A typical Wix kit for the TH400 will include the filter screen and a new pan gasket, which is everything you need for a standard service.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Filter Kit (Wix) | $11.74 - $20.43 |
| Shop Labor | $100 - $225 |
| Total Estimated Cost | $112 - $245 |
Pro Tip: Gasket Matters
When replacing the filter, it's a messy job that involves dropping the transmission pan. Ensure the kit you buy comes with a quality gasket. Some owners prefer a modern rubber or neoprene gasket over the traditional cork or fiber ones for a better seal.
Frequently Asked Questions (FAQ)
How often should I change my transmission filter?
For a classic vehicle like the CJ6A with a TH400, a good rule of thumb is to change the fluid and filter every 30,000 miles or every 2-3 years, especially if you use your Jeep for off-roading or towing.
Is this a difficult DIY job?
For a home mechanic, this is a feasible but messy job. It requires safely lifting the vehicle, draining the fluid, removing the pan, replacing the filter, and re-installing the pan with a new gasket. The difficulty is low to moderate, with the main challenge being the mess from the transmission fluid.
Are there any recalls or TSBs for the 1966-1968 CJ6A transmission?
No recalls or Technical Service Bulletins (TSBs) were found related to the transmission filter for the 1966-1968 Jeep CJ6A in the NHTSA database. Given the vehicle's age, this is expected.
Is the CJ6A filter the same as the one for a CJ5?
Yes, if the CJ5 is from the same era (late 1960s) and is also equipped with the optional TH400 automatic transmission, it would use the same filter kit. The vehicle model is less important than the type of transmission installed.
Technical Specifications
Fits the General Motors TH400 3-speed automatic transmission. Kit typically includes a screen-type filter and a pan gasket.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.