Crankshaft Seal Buying Guide — Cheap OEM Replacement Parts for Sale | REVXSC
Looking for cheap crankshaft seals that won't fail in 6 months? Whether you're chasing how to replace a front crankshaft seal, ford rear main seal leak repair, crankshaft seal replacement cost, best brand crank seal, PTFE rear main seal install dry, this guide covers what to buy, what to skip, and how to make sure the part you order actually fits your truck or car. Every crankshaft seal sold at REVXSC ships with a verified year/make/model/engine fitment table — no guessing.
What crankshaft seals actually do
In one sentence: the lip seal at the front or rear of the engine block that keeps oil inside the crankcase where the crankshaft exits to drive the timing belt or flywheel. When they wear out, you'll typically feel it before you see it — your car starts telling you something is wrong, and ignoring it gets expensive.
Signs you need new crankshaft seals
- oil leak at the front of the engine on the harmonic balancer
- oil on the bell housing flange (rear main)
- wet timing cover with fresh oil sling
- low oil level between changes
- burning oil smell from a hot engine
If you tick more than one box, replace before it leaves you on the side of the road. The repair gets a lot cheaper when you catch it early.
Also known as
Depending on the shop manual, region, or supplier you're reading, crankshaft seals are also called: crank seal, front main seal, rear main seal, front crankshaft oil seal, RMS. They all refer to the same component — when you're cross-referencing OEM and aftermarket part numbers, watch for these naming variations so you don't double-order the same item.
How much should you pay?
Online direct-ship from REVXSC undercuts dealer parts counters significantly. We carry quality replacement crankshaft seals from BCA, National, Felpro, Timken, SKF, Motorcraft, WJB / InMotion Parts, Mahle — every listing shows the price, the fitment chart, and real product photos. No mystery part numbers.
Featured crankshaft seals in stock right now
OEM vs aftermarket: which to choose
For crankshaft seals, the brand actually matters. BCA and National supply major automakers as OEM suppliers — when you buy their boxed retail product, you're getting the same engineering and tolerances. Choose between standard nitrile (NBR) seals for daily drivers, Viton/FKM seals for high-heat applications and synthetic oils, and PTFE (Teflon) seals on modern engines that require a dry installation..
Install: DIY or shop?
Difficulty: advanced. Bay time runs about 60–480 minutes with the right tools. Lifespan you should expect: 100,000-200,000 miles.
How REVXSC keeps prices low
Every listing includes a year/make/model/engine table.
ACDelco, Bosch, Dorman, Dayco, FEL-PRO and more.
Ships from US warehouses with real tracking.
No knockoff boxes, no rebranded junk.
Crankshaft Seal shipping to every US state
REVXSC ships crankshaft seals same-day from US fulfillment to every state. Whether you're chasing salt-corroded crankshaft seals in the Midwest, heat-fatigued parts in the Southwest, or just need a fast OEM-grade replacement, every order ships from the US with tracking. We deliver to:
Common questions Americans ask about crankshaft seals
What causes a crankshaft seal to leak?
Heat-hardened rubber after years of operation, a grooved or scored crankshaft surface, excessive crankcase pressure from a clogged PCV, and worn main bearings allowing crank movement are the top causes. Most seals fail simply from age and oil contamination.
How much does it cost to replace a rear main seal?
The seal itself runs $15-$50, but labor is brutal - $700-$1,500 because the transmission must come out. Front crank seals are far cheaper at $300-$700 since only the harmonic balancer and timing cover area need to come off.
Can I drive with a leaking rear main seal?
Yes if it's a slow weep, but you'll need to top off oil frequently and live with drops on your driveway. A fast leak can flood the clutch (manual) or flexplate area (auto) and contaminate clutches or solenoids, so fix bigger leaks promptly.
Is it worth replacing a rear main seal?
If the rest of the engine is healthy and the vehicle is worth more than $3,000, yes. If the engine already burns oil or has high mileage, many owners do the rear main with a clutch job, since the labor overlap saves hundreds.
How long does it take to replace a crankshaft seal?
Front crank seal: 2-4 hours DIY if you have a balancer puller and seal driver. Rear main seal: 6-10 hours because the transmission, flywheel, and on manuals the clutch all have to come out. Pros usually charge 5-12 hours of book labor.
What does a leaking front crank seal look like?
Oil sling shows up on the harmonic balancer, timing cover, and accessory belts. Sometimes a band of oily grime forms around the balancer pulley. Severe leaks drip from the front of the oil pan and contaminate the serpentine belt.
Should I replace the crankshaft seal during a timing job?
Yes, absolutely. The front crank seal is exposed and the parts cost is minimal - around $15-$30. Reinstalling old high-mileage timing components without a fresh seal is asking for a comeback in 20,000 miles.
Are PTFE rear main seals installed dry or with oil?
PTFE (Teflon) seals must go in completely dry - no oil, no assembly lube, nothing. The seal lip needs to ride on a dry crankshaft for the first few revolutions to establish its film. Oiling a PTFE seal almost always causes an instant leak.
Top US searches for crankshaft seals
Most-searched phrases from American shoppers comparing crankshaft seals this year — all of these are served by what REVXSC stocks:
This guide is updated as our crankshaft seal inventory and fitment data change. Last reviewed 2026-06-28.