If you’ve ever scraped factory RTV off a 7.3 and thought, “Why can’t all sealant work like that?”—you’re thinking of International T-442 RTV Silicone, part number 1830858C1.
In the Powerstroke world, it’s one of International’s best “boring” products: no hype, just a sealant that consistently seals when used where it’s supposed to.

 

Why people specifically want T-442

International T-442 is the right choice for metal-to-metal oil sealing areas, it's a proven sealant and helps avoid issues like oil foaming when RTV contacts engine oil. Other sealants are hit or miss, this one is a home run every time (assuming the right prepwork was done).

Common 7.3 / Super Duty applications

T-442 is commonly used on:

• Engine oil pans, timing/front covers, transmission pans, rear main seal areas
• HPOP reservoirs (metal-to-metal sealing areas where a gasket isn’t used)
• Half-moon seals and similar oil sealing spots
• Differential covers 
• And other metal to metal applications (but not for fuel)

Also: But don’t “RTV everything.” RTV should not be used on things like HPOP or oil cooler mounting gaskets, fuel fittings, and exhaust up-pipes.

 

Install tips (the stuff that prevents leaks)

• Final prep matters: it is recommended to use acetone or alcohol as the last wipe before applying.
• Don’t dawdle on oil pans: the oil pan should be installed within roughly 3 minutes of applying T-442.

Discontinued and getting scarce

Yes, T-442 has been discontinued by International, and it’s getting harder to source. But not from us. We've got a large supply that just came in, so fear not, we've got you covered (while supplies last).

Bottom line: if you want the real International T-442 (1830858C1), it’s worth grabbing while it’s still available at RiffraffDiesel.com.