Overview
The Crown Automotive 1 inch expansion freeze plug, part number J3178449, is a 1 inch expansion (freeze) plug for 4.0L engine or 5.0L (V8-304) engine applications. It fits a range of Jeep and Dodge Ram models built from 1970 through 2003.
Crown Automotive is a manufacturer and distributor of replacement parts for Jeep vehicles, and its range includes many factory-discontinued items. The plug carries UPC 848399058383. Check the plug size against your engine before installing.
Key features
- 1 inch expansion (freeze) plug design
- Fits 4.0L engine or 5.0L (V8-304) engine applications
- Direct fit listing, per Crown Automotive
- Fitment list covers Jeep CJ, Cherokee, Comanche, Grand Cherokee, Grand Wagoneer, Wagoneer and Wrangler YJ, plus Dodge Ram 2500 and 3500
Replacing a freeze plug
Freeze plugs seal the core holes in an engine block. Because they sit between the coolant and the outside of the block, they can corrode from the inside out, and a worn plug may weep coolant long before it fails completely.
When replacing one, inspect the bore for pitting, cracks or a rounded edge. A damaged bore can prevent a new plug from seating, so it may need cleaning or a different approach before the new plug goes in. Use the sealant type called for in your service manual and drive the plug in squarely so the cup faces outward as intended.
- Look for coolant residue or rust streaks around the plug
- Inspect the bore for pitting or cracks before installing
- Clean the bore so the plug seats evenly
- Refill and bleed the cooling system after the repair
- Check for leaks after the engine reaches operating temperature
Specifications
| Brand | Crown Automotive |
|---|---|
| Part number | J3178449 |
| UPC | 848399058383 |
| Size | 1 inch |
| Type | Expansion (freeze) plug |
| Engine applications | 4.0L engine or 5.0L (V8-304) engine |
| Fitment listing | Direct fit |
Vehicle fitment
Crown Automotive’s manufacturer fitment list covers these vehicles: Dodge Ram 2500 and 3500 from 1994 to 2003; Jeep Cherokee SJ from 1974 to 1983; Jeep Cherokee XJ from 1987 to 1996; Jeep CJ5 from 1971 to 1981, CJ6 from 1971 to 1975 and CJ7 from 1976 to 1981; Jeep Comanche from 1987 to 1992; Jeep Commando from 1972 to 1973; Jeep Grand Cherokee ZJ from 1993 to 1996; Jeep Grand Wagoneer SJ from 1984 to 1991; Jeep J-2500 and J-2600 from 1970 to 1973; Jeep J-3800 from 1970 to 1971; Jeep J-4500, J-4600, J-4700 and J-4800 from 1971 to 1973; Jeep Wagoneer SJ from 1972 to 1983; and Jeep Wrangler YJ from 1991 to 1995.
The list does not include Wrangler TJ or Grand Cherokee WJ models, and it ends with the 1996 Cherokee XJ and the 1996 Grand Cherokee ZJ. Confirm your vehicle’s year, model and trim before ordering.
What’s included
The package contains one 1 inch expansion (freeze) plug. Check the package contents against your installation before starting.
