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Lexus GX470 Rear Main Seal Replacement Cost

Know what price you should pay to get your vehicle fixed.

The average cost for a Lexus GX470 rear main seal replacement is between $97 and $109. Labor costs are estimated between $44 and $56 while parts are priced at $53. Estimate does not include taxes and fees.
Note about price: This service is typically done as part of a bigger, more expensive repair, so the estimate you see above may not represent your total cost. Some of these bigger related repairs are listed in the table below. Talk with a RepairPal Certified shop to learn which repairs may be right for you.

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What is a rear main seal?

The rear main seal is the mechanical seal on the end of the crankshaft. It's often found in a housing that attaches to the rear of the engine block.

How does the rear main seal work?

The crankshaft protrudes slightly from the rear of the engine block so that it can connect to the transmission. The rear main seal covers the end of the crankshaft to keep the oil inside the engine.

What are the symptoms related to a bad rear main seal?

When the rear main seal fails, you may see an oil stain on the ground where the vehicle is parked. The leak will appear to be coming from between the engine and the transmission, but over time it can coat the underside of the car near the engine. In extreme cases, the leaking oil will coat the flywheel, and can cause clutch slippage in vehicles with a manual transmission.

Can I drive with a rear main seal problem?

A bad rear main seal will typically leak oil. You can drive the car in this situation, but you'll need to check the oil and top it off more often.

Any oil leak, including a bad rear main seal, should be fixed, though, as it increases the risk of damaging the engine due to a low oil level. Damage to timing chain tensioners, camshaft bearings, crankshaft bearings and other lubricated components can be expensive to repair.

How often do rear main seals need to be replaced?

The lifespan of the rear main seal varies greatly, depending on the vehicle and driving conditions. The seal doesn't wear like a tire or a ball joint, but eventually the gasket's rubber will degrade. Due to its location, it can easily go unnoticed.

How are rear main seal issues diagnosed?

It's easiest to spot oil leaks when they are new or fresh. The technician may clean the fluid around the leak and ask you to come back later to confirm where the leak is coming from.

With bigger or older oil leaks, the technician will also add a dye to the oil. After the vehicle has been driven with the dye, a UV light will be used to pinpoint the leakage and determine what repairs are needed.

Rear Main Seal Replacement Cost Estimates

The average cost for a Rear Main Seal Replacement is between $97 and $109 but can vary from car to car.

How is a rear main seal replaced?

To gain access to the seal, the technician will remove the transmission and flywheel or flexplate. Depending on the type of vehicle, either the seal will be removed from the engine block or the housing that holds the seal will be removed in its entirety.

The surfaces will be cleaned, and the new rear main seal will be installed. The technician will put everything back together and then check to make sure any leaks have stopped.

RepairPal recommendations for rear main seal issues

Proper diagnosis is key in pinpointing any oil leak. An bad head gasket, a split line or a more expensive transmission leak could be the source of the fluid.

If the vehicle has a manual transmission, the clutch should be serviced at this time, as it has to be removed in order to access the rear main seal. Transmission mounts and driveshaft support bearings should be inspected for wear and replaced if necessary.

What to look out for when dealing with rear main seal issues

Oil will damage rubber components, such as hoses, belts and motor mounts. It's important to fix the leak before it can ruin other parts of the car.

With a rear main seal leak, it also becomes even more important to check the oil level. The oil in the lubrication system is under pressure, so driving with an oil leak is forcing oil out through the seal. 

Can I replace the rear main seal myself?

We recommend having a professional repair shop replace this part. Proper diagnosis is key, and crucial parts such as the transmission, flywheel and oil pan may need to be removed.