Need a rear main seal that fits your engine and keeps oil where it belongs? Here are nine top choices for 2026 covering common repairs, performance swaps, and stop‑leak fixes.
Find full cover kits like Dorman’s die‑cast option with gasket and hardware, precision Fel‑Pro kits matching factory dimensions, nitrile and two‑pack VW seals for air‑cooled rigs, and LS/GM seals built for high‑torque engines.
Also included are metal‑bonded and garter‑spring performance seals plus temporary additives from XADO and Bar’s Leaks for short‑term use before replacement.
| Dorman 635-518 Engine Rear Main Seal Cover Compatible with Select Models |
| Direct OEM Fit | Product Type: Rear main seal cover kit | Purpose / Function: Prevent/repair rear main oil leaks | Compatibility / Fit Guidance: Select vehicle makes/models — verify with fit tool | VIEW LATEST PRICE | Read Our Analysis |
| FEL-PRO BS 40685 Rear Main Seal Set | Application-Specific Fit | Product Type: Rear main seal set | Purpose / Function: Seal crankshaft / stop oil leaks | Compatibility / Fit Guidance: Specific Honda/Acura/Saturn models — verify vehicle info | VIEW LATEST PRICE | Read Our Analysis | |
| XADO ATOMEX Engine Oil Additive Stop Leak (250 ml) |
| Seal Restorer | Product Type: Engine oil additive / stop-leak (seal rejuvenator) | Purpose / Function: Restore seals and stop engine oil leaks | Compatibility / Fit Guidance: Universal (auto/motorcycle/marine) compatibility | VIEW LATEST PRICE | Read Our Analysis |
| FEL-PRO BS 40430 Engine Crankshaft Seal Kit for Honda Civic |
| Classic Honda Match | Product Type: Rear main/crankshaft seal kit | Purpose / Function: Seal rear main / crankshaft to prevent leaks | Compatibility / Fit Guidance: Specific Acura/Isuzu/Civic-era models — verify fit | VIEW LATEST PRICE | Read Our Analysis |
| Rear Main Seal for Type 1 VW Engines (2-Pack) |
| Vintage VW Replacement | Product Type: Rear main crankshaft seal (2-pack) | Purpose / Function: Replace rear main seal to stop oil leaks | Compatibility / Fit Guidance: Type 1 VW engines (Beetle, Karmann Ghia, Bus) — verify year/engine | VIEW LATEST PRICE | Read Our Analysis |
| Rear Main Seal Cover Kit for GM 4.8–6.2L |
| GM LS Specialist | Product Type: Rear main seal cover kit (with gasket & bolts) | Purpose / Function: Replace rear main cover/seal to prevent leaks | Compatibility / Fit Guidance: GM 4.8–6.2L family (many Chevrolet/GMC/Cadillac) — verify fit | VIEW LATEST PRICE | Read Our Analysis |
| Rear Main Seal Gasket Set for GM LS Engines |
| Complete Gasket Kit | Product Type: Rear main seal gasket set | Purpose / Function: Provide rear main gasket sealing for LS engines | Compatibility / Fit Guidance: GM LS / Vortec engines (4.8–6.2L) — verify fit | VIEW LATEST PRICE | Read Our Analysis |
| Bar’s Leaks Rear Main Seal Repair 16.9 oz |
| Fast Stop-Leak | Product Type: Rear main seal repair (liquid stop-leak) | Purpose / Function: Chemically stop rear main and other oil leaks | Compatibility / Fit Guidance: All gasoline and diesel engines — generally compatible | VIEW LATEST PRICE | Read Our Analysis |
| FEL-PRO BS 40640 Engine Crankshaft Seal Kit for Chevrolet Silverado 1500 |
| Silverado Ready | Product Type: Crankshaft/rear main seal kit | Purpose / Function: Crankshaft rear main sealing to stop leaks | Compatibility / Fit Guidance: Specific GM Chevrolet/GMC/Cadillac models — verify fit | VIEW LATEST PRICE | Read Our Analysis |
More Details on Our Top Picks
Dorman 635-518 Engine Rear Main Seal Cover Compatible with Select Models
In case you need a reliable rear main seal cover that fits like the original and stops leaks, the Dorman 635-518 is a strong choice for owners who want a direct replacement that won’t add hassle. You’ll find a complete kit with the cover, new gasket, installation hardware, and an updated seal so you don’t hunt for parts. The die-cast aluminum cover gives durable, leak-free performance and the new seal reduces repeat repairs. Before you buy, you’ll verify fit through entering make, model, and trim in the garage tool and checking the Amazon Confirmed Fit notes for details.
- Product Type:Rear main seal cover kit
- Purpose / Function:Prevent/repair rear main oil leaks
- Compatibility / Fit Guidance:Select vehicle makes/models — verify with fit tool
- Included Contents / Kit Components:Seal cover, new gasket, installation hardware, updated seal
- Material / Construction:Die-cast aluminum cover with updated seal (seal material not specified)
- Verification / Quality Claims:Direct replacement, tested for fit and leak prevention
- Additional Feature:Die-cast aluminum construction
- Additional Feature:Updated seal design
- Additional Feature:Includes installation hardware
FEL-PRO BS 40685 Rear Main Seal Set
Application-Specific Fit
View Latest PriceShould you want a rear main seal kit that fits a wide range of Honda and Acura engines and installs without guesswork, the FEL-PRO BS 40685 Rear Main Seal Set is a strong choice. You’ll like that it’s made for Fel-Pro and designed to meet or exceed original equipment specs. It includes plastic seal components and a plain bearing that works along engine oil. Fitment covers many Acura and select Saturn and Honda models, so verify year, make, model, engine, and trim before you buy. It ships light, measures about 5 by 5 by 1 inches, and carries Fel-Pro support and warranty docs.
- Product Type:Rear main seal set
- Purpose / Function:Seal crankshaft / stop oil leaks
- Compatibility / Fit Guidance:Specific Honda/Acura/Saturn models — verify vehicle info
- Included Contents / Kit Components:Seal components (plastic seals) — rear main seal set
- Material / Construction:Plastic seal components
- Verification / Quality Claims:Meets/exceeds OE specifications; application-specific design
- Additional Feature:Plastic seal components
- Additional Feature:Wide Acura coverage
- Additional Feature:Detailed part identifiers
XADO ATOMEX Engine Oil Additive Stop Leak (250 ml)
Should you own a high-mileage or older vehicle and want a simple way to stop oil leaks without an expensive shop visit, XADO ATOMEX Engine Oil Additive Stop Leak (250 ml) is built for you. You’ll pour this into the oil to restore rubber gasket elasticity and rejuvenate seals, valves, and cylinders. It stops existing oil leaks, including rear main seal drips, and helps prevent new ones. It works across cars, motorcycles, and marine engines, reduces engine noise, lowers oil use, and smooths operation. You’ll extend component life, cut maintenance costs, and delay repairs with this multi-purpose treatment.
- Product Type:Engine oil additive / stop-leak (seal rejuvenator)
- Purpose / Function:Restore seals and stop engine oil leaks
- Compatibility / Fit Guidance:Universal (auto/motorcycle/marine) compatibility
- Included Contents / Kit Components:250 ml bottle of additive (no hardware)
- Material / Construction:Chemical formulation (additive) — liquid
- Verification / Quality Claims:Restores seal elasticity; stops/prevents leaks; prolongs life
- Additional Feature:Restores rubber elasticity
- Additional Feature:Multi-vehicle compatibility
- Additional Feature:Reduces oil consumption
FEL-PRO BS 40430 Engine Crankshaft Seal Kit for Honda Civic
You’ll appreciate the FEL-PRO BS 40430 Engine Crankshaft Seal Kit should you want a reliable, application-specific rear main seal that fits older Honda and Acura models without guesswork. You’ll get a Fel-Pro rubber seal kit made for 1986–2005 Honda and Acura applications, so fit, form, and function match OEM intent. You’ll like the machined exterior and professional-grade sealing that meets or exceeds original specs. You should verify year, make, model, engine, and trim before ordering and check Amazon Confirmed Fit annotations. You’ll value the light four ounce kit, clear part numbers, warranty access, and easy return policy.
- Product Type:Rear main/crankshaft seal kit
- Purpose / Function:Seal rear main / crankshaft to prevent leaks
- Compatibility / Fit Guidance:Specific Acura/Isuzu/Civic-era models — verify fit
- Included Contents / Kit Components:Rear main seal(s) / crankshaft seal kit (single count)
- Material / Construction:Rubber seal / machined exterior (rubber)
- Verification / Quality Claims:Meets/exceeds OE specs; validated for fit/form/function
- Additional Feature:Rubber construction
- Additional Feature:Discontinued by manufacturer
- Additional Feature:Long product history
Rear Main Seal for Type 1 VW Engines (2-Pack)
Should you drive a classic Type 1 Volkswagen and need a reliable fix for a leaking rear crankshaft, this 2-pack rear main seal is a smart choice because it matches the fit and function those engines require while giving you a spare for future work. You’ll like that the nitrile rubber resists oil, heat, and friction, so the seal holds oil pressure and keeps leaks away. It fits Beetle, Super Beetle, Karmann Ghia, and corresponding Transporter years provided you verify engine type. Installation is direct OEM replacement, simple provided you follow repair steps. It’s light, durable, and gives peace of mind.
- Product Type:Rear main crankshaft seal (2-pack)
- Purpose / Function:Replace rear main seal to stop oil leaks
- Compatibility / Fit Guidance:Type 1 VW engines (Beetle, Karmann Ghia, Bus) — verify year/engine
- Included Contents / Kit Components:Two rear main seals (2-pack)
- Material / Construction:Nitrile rubber
- Verification / Quality Claims:OEM direct-replacement claim; durable nitrile construction
- Additional Feature:Nitrile rubber material
- Additional Feature:Two-pack value
- Additional Feature:OEM direct replacement
Rear Main Seal Cover Kit for GM 4.8–6.2L
Should you need a tough, precise repair for GM 4.8L to 6.2L engines, this Rear Main Seal Cover Kit is a smart choice for DIYers and mechanics who want a reliable, direct replacement. You’ll get a high quality aluminum cover, gasket, and bolts that match OEM specs and resist corrosion. It fits many Chevrolet, GMC, Buick, Cadillac, Pontiac, Hummer, Isuzu, and Saab models with 4.8L through 6.2L engines, replacing parts 635-518, 12633579, 12639250. Before you buy, verify fitment for your vehicle. Should questions come up, seller support is available and will reply promptly.
- Product Type:Rear main seal cover kit (with gasket & bolts)
- Purpose / Function:Replace rear main cover/seal to prevent leaks
- Compatibility / Fit Guidance:GM 4.8–6.2L family (many Chevrolet/GMC/Cadillac) — verify fit
- Included Contents / Kit Components:Rear main seal cover, gasket, bolts
- Material / Construction:High-quality aluminum cover
- Verification / Quality Claims:Engineered to OEM specifications; corrosion resistant
- Additional Feature:Replaces multiple OEM numbers
- Additional Feature:Broad GM model fitment
- Additional Feature:High-quality aluminum
Rear Main Seal Gasket Set for GM LS Engines
In case you drive or work on GM LS engines and want a reliable, long-lasting rear main seal, the BS 40640 Rear Main Seal Gasket Set fits the bill and gives you confidence during installation and use. You’ll like that it replaces OE numbers 89060436 and 12639249, so fitment is straightforward. It suits Vortec 4.8 to 6.2L engines in many Chevy, GMC, Cadillac, Buick models from 1999 to 2020. The kit withstands heat, pressure, and harsh fluids, and it includes gloves, a cleaning brush, and a 12-month warranty. Contact the seller via email should you need help.
- Product Type:Rear main seal gasket set
- Purpose / Function:Provide rear main gasket sealing for LS engines
- Compatibility / Fit Guidance:GM LS / Vortec engines (4.8–6.2L) — verify fit
- Included Contents / Kit Components:Rear main gasket seal set, gloves, cleaning brush
- Material / Construction:Sealing materials meeting equipment specs (gasket materials)
- Verification / Quality Claims:Meets/exceeds equipment specs; durable for high temps/pressures
- Additional Feature:Includes cleaning brush
- Additional Feature:Installation gloves included
- Additional Feature:12-month warranty
Bar’s Leaks Rear Main Seal Repair 16.9 oz
Should you want a simple, affordable fix for a stubborn rear main leak, Bar’s Leaks Rear Main Seal Repair is made for drivers and small-fleet techs who need fast results without a full engine teardown. You add the full 16.9 ounce bottle to the crankcase at an oil change, and you won’t overfill when you check levels. It restores dried, shrunken seals and can stop many leaks within 100 miles or two days. It works on gasoline and diesel engines, and with conventional or synthetic oil. You’ll appreciate easy application, fleet-friendly use, and a brand that’s lasted since 1947.
- Product Type:Rear main seal repair (liquid stop-leak)
- Purpose / Function:Chemically stop rear main and other oil leaks
- Compatibility / Fit Guidance:All gasoline and diesel engines — generally compatible
- Included Contents / Kit Components:16.9 oz bottle of repair fluid (no hardware)
- Material / Construction:Chemical formulation (liquid)
- Verification / Quality Claims:Proven to restore hardened seals; expected leak stop timeframe
- Additional Feature:Bottle pour-in application
- Additional Feature:Works with synthetic oil
- Additional Feature:Stops leaks within 100 miles
FEL-PRO BS 40640 Engine Crankshaft Seal Kit for Chevrolet Silverado 1500
Should you want a dependable crankshaft seal kit that fits a wide range of GM and related trucks and SUVs, choose the FEL-PRO BS 40640; it’s built for owners and mechanics who need a precise, worry-free replacement. You’ll find this kit fits many models, from early 2000s Cadillacs to mid 2010s Escalades and Silverados. Before you buy, check year, make, model, engine, and trim, and use the Amazon Confirmed Fit bar for notes. FEL-PRO designs and validates each part for fit, form, and function. It meets or exceeds OE specs, so you can trust its quality.
- Product Type:Crankshaft/rear main seal kit
- Purpose / Function:Crankshaft rear main sealing to stop leaks
- Compatibility / Fit Guidance:Specific GM Chevrolet/GMC/Cadillac models — verify fit
- Included Contents / Kit Components:Rear main/crankshaft seal kit (seal components)
- Material / Construction:Application-specific seal materials (meets OE specs)
- Verification / Quality Claims:Meets/exceeds OE specs; validated for repair applications
- Additional Feature:Validated fit/form/function
- Additional Feature:Broad GM vehicle coverage
- Additional Feature:Meets OE specifications
Factors to Consider When Choosing Car Main Seals
As you’re picking a main seal, consider initially about material and durability because the wrong compound will wear out fast and leave you stranded. Also check vehicle compatibility and seal design type so the part fits and matches how your engine moves. Finally consider installation complexity and leak prevention performance since an easy install and a tight seal save you time, money, and worry.
Material And Durability
Because the main seal sits where oil, heat, and motion meet, your choice of material and design makes a big difference in how long it lasts and how well it protects your engine. Pick seals made from high quality elastomers like nitrile NBR, fluoroelastomer FKM or hydrogenated nitrile HNBR because they resist oil, heat, and ozone. HNBR and FKM handle higher temperatures and longer service life than standard NBR. Also favor metal bonded constructions that keep the seal stable and resist extrusion under crankshaft load. Look for upgraded lip designs such as dual lips, garter springs, or hydrodynamic lips to keep contact pressure and prevent leaks. Finally, match seal chemistry to your oil and guarantee smooth, properly hardened shaft surfaces for best durability.
Vehicle Compatibility Fit
Should your car’s rear main seal doesn’t match the exact engine and year, you can end up with a persistent leak and a lot of wasted time. You’ll want to verify the seal is specified for your vehicle’s exact year, make, model, and engine displacement because small differences matter. Also confirm the seal matches engine orientation and crankshaft details like single versus dual lip, stepped journals, or counterweight clearances so the seal won’t rub or leak. Check if you need an engine-specific kit with cover and gasket or a standalone seal since some cars require the housing replaced. Match mounting bolt pattern and gasket surface dimensions to the original part. Finally use the OEM part number or service manual dimensions whenever cross-referencing aftermarket options.
Seal Design Type
You’ve already checked fit and mounting details, and now it helps to look at what the seal is actually made to do. You’ll pick a lip seal type first. Single lip works for basic sealing. Double lip adds protection from pressure and debris, so it lasts longer in rough conditions. Next, consider material. Nitrile is common and affordable. Viton or fluorocarbon handles higher heat and harsh chemicals. Silicone and PTFE suit special needs, so match material to your engine’s temps and fluids. Many seals use a garter spring to keep steady pressure on the lip as parts wear and expand. Also look for dust or secondary lips to keep grit off the main seal. Finally, check profile and shaft finish compatibility so the lip contacts correctly and won’t leak.
Installation Complexity Level
As you’re picking a main seal, consider about how hard it will be to install and how that affects cost and risk. You’ll face different levels of access depending on your car. Front wheel drive transverse engines often let you reach the seal more easily. Longitudinal or rear wheel drive layouts usually need transmission separation or engine support, which adds hours. Expect 3 to 6 hours with an experienced tech whenever removal is required. You’ll remove flywheel, starter, clutch or torque converter and follow precise crankshaft positioning and seal seating depth. Use correct tools like seal drivers and alignment fixtures and check torque specs with measuring tools. Whenever you do it wrong, oil leaks and premature seal failure can follow, so follow factory procedures.
Leak Prevention Performance
Reliability matters more than you might suppose whenever picking a main seal, because a small choice now can stop a big leak later. You’ll want a material and hardness that match your engine temperature and oil type, like nitrile, silicone, or fluoroelastomer with the right durometer rating. Pay attention to lip design and surface finish since single or double lips, spring-energized designs, and smooth sealing faces control contact pressure and wear. Also check shaft and housing tolerances, including concentricity and surface roughness specified by the maker, as gaps or rough shafts accelerate failure. Look for installation-friendly features such as integrated gaskets, dust lips, and sturdy housings to avoid distortion. Finally, verify chemical compatibility with oils, additives, and contaminants so the seal won’t harden or swell.
Maintenance And Longevity
Checking and caring for main seals keeps small problems from becoming expensive repairs, and a few simple habits make a big difference. You should inspect the crankshaft area for oil seepage and check oil level every month so you catch leaks promptly. Use the manufacturer recommended oil viscosity and follow change intervals, usually every 5,000 to 10,000 miles, because fresh oil prevents seal swelling and hardening. Keep engine temperature normal and fix cooling problems quickly since heat speeds seal wear. Whenever you work on the engine, keep dirt and solvents away and use clean procedures to avoid abrasion or chemical damage. For high mileage engines, add periodic seal conditioning or thorough inspections during major services to maintain elasticity and prevent leaks.
Warranty And Support
You’ve been keeping an eye on seal wear and routine care, and now you’ll want the same attention while choosing warranty and support for main seals. You should firstly check the warranty length, commonly 12 months, and read what failures or damage are covered. Also confirm installation rules and voiding conditions, since some warranties require professional fitting or forbid certain fluids and engine mods. Next, look for clear after sales channels like phone, email, and online returns, plus response time promises for claims and replacements. Ask whether the supplier provides corrosion, material, or performance test documents and whether claims need diagnostic reports. Finally, verify return windows, proof of purchase rules, and who pays return or diagnostic shipping.
