Should You Install a TH400 Transmission Catch Can? | Benefits & Maintenance Tips

What is a TH400 Transmission Catch Can?

A TH400 transmission catch can is a device that is installed in order to catch fluid blow-by, condensation, and excess crankcase gases that can gather in the crankcase ventilation system of engines that have a Turbo-Hydramatic 400 (TH400) automatic transmission.

How Do TH400 Transmission Catch Cans Work?

TH400 catch cans work by providing a place for excess crankcase gases and fluids to collect rather than being sent back into the intake system. This helps prevent contamination of the oil and intake components.

The TH400 transmission catch can is installed somewhere along the crankcase ventilation route, often between the PCV valve and intake manifold. Inside the catch can are baffles that are designed to condense fluids out of the gases as they pass through. The excess oil and condensation collects in the bottom of the can, while the air continues flowing through.

This is beneficial because allowing oil blow-by and condensation to continually pass through the ventilation system and back into the engine can cause a number of issues such as:

• Oil contamination in the intake system
• Reduced engine performance
• Carbon build up
• Corrosion of components

By collecting these excess fluids and gases in a catch can, it keeps the crankcase ventilation system clean while also allowing proper ventilation to occur.

When Should a TH400 Transmission Catch Can Be Used?

Here are some instances when installing a TH400 catch can would be recommended:

• On highly modified engines - Upgraded turbochargers, superchargers, nitrous systems, and high performance internal components can all increase blow-by gases and contamination.
• On vehicles used for racing/performance driving - The heat and demands placed on the engine require proper ventilation to prevent oil breakdown and excess pressure.
• On older engines - As engines accumulate mileage and wear internally, blow-by gases tend to increase so a catch can helps manage this.
• In humid climates - Water vapor and condensation can gather in the system so a catch can prevents that from reaching the engine.

What are the Benefits of Using a Catch Can?

Installing a TH400 transmission catch can provides several benefits including:

• Keeps intake components cleaner
• Reduces carbon deposits inside the engine
• Allows proper air flow through crankcase system
• Lowers risk of oil contamination throughout the ventilation system
• Prolongs life of intake gaskets and seals
• Easy to drain and clean at routine intervals
• Inexpensive to install and maintain

Selecting the Right TH400 Transmission Catch Can

If you've decided that adding a catch can would be beneficial for your TH400 powered vehicle, choosing the proper one is key to maximizing its effectiveness. Here are the main factors to consider when selecting a catch can:

Material

Most catch cans are made from aluminum or steel metals. Aluminum is lighter in weight while steel offers added durability for very demanding applications. Power coat finishes help prevent exterior corrosion.

Capacity

Selecting a catch can with adequate capacity is crucial to prevent overflow. Most range from 8 ounces to 40 ounces based on the intended vehicle and how frequently it will be drained. If installing on a demanding race application, opt for larger capacity.

Inlet/Outlet Ports

Commonly there are two ports (inlet and outlet) on opposite sides of the can to allow for ventilation flowthrough. Make sure the ports properly align with existing crankcase lines or vents during installation.

Mounting Position

Since oil and moisture collect in the bottom of the can, try to mount it at an angle where this debris can avoid the return line back to the engine after drain intervals. Some cans offer mounting brackets or are shaped to promote this angled installation.

Fittings & Hoses

Most TH400 catch cans come with the necessary fittings, baffles, and adapters needed to properly channel vent hose sizes. Make sure the can you select is compatible with your vehicle's hose diameters to prevent leaks or blockages.

Brand Reputation & Budget

As with any automative component, purchasing a catch can from a reputable brand provides peace of mind that it won't fail. Moroso and Canton Racing offer exceptional catch cans but there are also many other quality options at lower price points.

Maintaining Your TH400 Transmission Catch Can

Once you've completed the initial installation, following these tips will keep your TH400 catch can working properly for maximum benefit:

Routine Draining

Check and drain the collected oil and condensation from your catch can ever few months or according to your vehicle usage. Allowing too much liquid to build up can cause it to reach the return line. For racing setups, check it more frequently.

Clean the Baffles

Over time, debris from blow-by gases can build up on the internal baffles inside the can. Periodically remove them to clean off the sediment using brake cleaner fluid or similar solvent.

Inspect Hoses & Fittings

Ensure clamps are properly tightened on all hoses connected to the catch can's ports. Also check for cracking damage and replace deteriorated vent hoses as needed.

Keeping up with these simple maintenance practices allows your TH400 catch can to prevent unwanted vapors from reaching your engine for the long haul.

Conclusion

Installing a catch can for your TH400 transmission equipped vehicle provides the vital benefit of collecting harmful moisture, condensation, and excess crankcase gases generated from oil blow-by. This keeps damaging oil vapor and residue from cycling continuously through your engine. In addition to improved engine operation and component longevity, TH400 catch cans are inexpensive to install and easy to service at regular intervals.

FAQs

How often should I drain my TH400 catch can?

Most experts recommend draining your TH400 catch can ever few months. For race vehicles or very high performance builds, drain it more frequently such as each month or even as needed between usage if it fills quickly in your application.

Where is the best place to mount my catch can?

Ideally you should mount the catch can at a slight diagonal or angle. This allows the collected oil/liquids to avoid entering the outlet port and instead remain trapped in the can until drain intervals. Some cans have specific inlet/outlet orientations or mounting brackets to accommodate angled installation.

What size catch can do I need?

Select a catch can that offers adequate capacity for your vehicle's usage frequency. Most fall between 8 ounce and 40 ounce capacity. The higher performance your engine build, the more blow-by it generates, requiring more reserve capacity before needing drained.

Will a catch can negatively affect my engine?

No - Adding a catch can is purely beneficial in properly routing blow-by gases and moisture out of your crankcase system. It does not alter any existing ventilation and simply provides a place to condense contaminants before they reenter the engine. There are no negatives to installing one.