The transfer case is the heart of any 4×4 drivetrain, splitting power between the front and rear axles. Unlike simple covers, the transfer case assembly often consists of two finely machined case halves (often aluminum) bolted together. This structure demands a specialty sealant to prevent leaks of high-viscosity, high-additive transfer case fluid.
Using standard RTV (Room Temperature Vulcanizing silicone) in this application is a common mistake. RTV forms rubbery strands that can break off inside the case, contaminating the fluid, clogging oil passages, and leading to catastrophic internal damage.
The only professional solution for aluminum-on-aluminum, tight tolerance case halves is a robust anaerobic sealant.
INCURE HeatGrip™ 504 Flexible Anaerobic Flange Sealant
The INCURE HeatGrip™ 504 is specifically engineered for rigid, close-fitting metal flanges that experience vibration. It is the perfect choice for transfer case halves as it delivers the high strength needed for load-bearing joints, the chemical resistance for aggressive gear fluids, and the flexibility to manage the inevitable movement and vibration of the drivetrain.
| Feature & Benefit | Technical Insight for Transfer Cases | Conversion Value |
| Non-Clogging Anaerobic Cure | Cures only in the absence of air and when confined between the metal flanges. Excess material squeezed to the inside remains liquid and harmlessly washes away in the fluid. | Protect Your Internals: Eliminate the risk of sealant “ooze” contaminating expensive gears, chains, and oil passages. |
| Flexible, Vibration-Resistant Bond | Engineered to cure with a semi-flexible layer, adapting to minor flange movement from drivetrain torque, shock loads, and road vibration. | Dynamic Seal Integrity: Maintain a leak-proof seal under the constant, high-stress movement of off-roading or heavy hauling. |
| Ideal for Machined Case Halves | Fills extremely small gaps (up to 0.25 mm) and is designed for the fine tolerances and uniform material (often aluminum) of transmission and transfer case splits. | Perfect OEM-Spec Fit: Achieve a thin, even seal that maintains the critical component geometry and torque specifications. |
| Excellent Fluid Compatibility | Offers high resistance to all common transfer case lubricants, including specialized ATF, specific synthetic gear oils, and friction modifiers. | Total Chemical Immunity: Ensure the sealant won’t degrade, soften, or dissolve when constantly immersed in hot, working fluid. |
Application Steps: Sealing Split Case Halves
Preparation (Zero Tolerance): Surface cleanliness is paramount. Use a chemical cleaner (like acetone or industrial degreaser) to thoroughly clean and dry both mating surfaces of the case halves. The flanges must be free of all oil, old sealant, or dirt.
Application: Apply a single, continuous, thin bead of HeatGrip™ 504 to one of the two mating surfaces. Ensure the bead completely surrounds all bolt holes and runs just inside the oil-wetted edges of the flange. Do not spread or smooth the bead.
Assembly: Assemble the case halves immediately. Install and hand-tighten the bolts to hold the components in place.
Torquing & Curing: Torque the bolts to the manufacturer’s specified value in the proper sequence (typically a star or cross pattern). Allow a full 24 hours for the sealant to achieve its final cure strength before introducing fluid or placing the component into service.