Cost of replacing the rear main seal [prices for 2024]
The crankshaft seal is an important component that prevents oil leaks. This seal is susceptible to cracking and damage from natural wear and tear over the life of your vehicle. If you see oil puddles under your car or truck, this could indicate a problem with the rear main seal.
Question: How much does it cost to replace the rear main seal?
Question: How many hours does it take to replace a rear main oil seal?
What is the rear main seal?
The rear main oil seal is a gasket (sealing) that forms a tight seal that keeps oil inside the engine’s rear. These seals are usually made of synthetic rubber, nitrile, silicone, Viton, or PTFE rubber.
The rear main oil seal is located where the crankshaft connection meets the transmission. The seal itself is small and is fairly simple. However, it is a very important component that does an important job.
Over time, the seal can become loose, damaged, or corroded. With normal wear and tear or harsh conditions, the seal can fail and cause a leak. Oil leaks from this area of the engine can cause more serious problems if the engine is left unrepaired for too long.
A faulty or damaged rear engine seal can cause oil to leak onto the clutch in manual transmission vehicles, causing problems such as slipping and rattling. Regardless of where the oil leaks, it’s important to fix the problem immediately.
What causes the rear main seal to fail?
The materials used to make seals make them vulnerable to damage and component wear over time. The age of the vehicle is the main reason the rear main seal can fail and leak over time.
However, running the engine when the oil level is low can also exacerbate the problem. If the seal dries out, it can harden and shrink. Once the seal hardens, it becomes vulnerable to cracks, tears, and other damage.
Other conditions that contribute to rear main seal leakage include:
- Excessive heat (engine overheating) if the engine is idling for long periods or high vehicle mileage.
- External or environmental conditions can also lead to faster seal wear and sealant failure.
- For example, mechanical failure – hitting a curb can cause a system breakdown and require significant financial outlay.
- Using more economical synthetic oil rather than high-quality oil or premium lubricant.
- Ignoring maintenance schedules.
To avoid crankshaft oil seal problems, systematically monitor the performance fluid level, select only quality oil grade for use, and adhere to the upkeep timetable.
Diagnosing a rear main seal problem
Diagnosing a rear main seal problem can be difficult in a standard vehicle inspection. However, some common signs of a rear main seal leak can indicate a rear main seal failure.
An oil puddle under the vehicle
It is the primary indicator that there may be a problem with the rear main seal. Oil puddles or fluid drips in the garage or driveway indicate that oil is leaking from somewhere, but you’ll need to take it to a mechanic to isolate the source of the leak.
Low oil level
Even if you don’t see a puddle of oil under your car, there could still be a leak. If your car is running low on oil and you have to refill it between scheduled oil changes, this is a likely sign that oil is leaking somewhere.
Sometimes, the oil doesn’t leak fast enough to leave visible puddles that the owner may notice. If you need to top off the oil in your engine or suspect you leak, try parking your car in your driveway and letting it run for about 15 minutes. It will allow for a quick and efficient leak detection.
Afterwards, move the car and look underneath for signs of lubrication loss. Sometimes, leaving the car idling will reveal a small oil leak you wouldn’t otherwise notice.
Rear main seal leak repair cost
The final rear main seal leak repaid cost depends on the car’s make and model. The part itself is relatively inexpensive. You can find quality offers in parts stores. The rear main seal cost ranges from 50 to 150 U.S. dollars. However, the repair price will require a much more substantial financial investment.
Not all car owners realise how labour-intensive replacing the rear crankshaft oil seal is. Because of its peculiar location, it is necessary to dismantle the engine or gearbox. This process can take about 5-7 hours. We discuss weeks of labour if you try to do this work independently. The rear main seal repair cost can be quite high. But despite this, it is better to refrain from such manipulations alone.
Suppose affordability assessment is in the language of figures. An hour of work is estimated in 2024 at 75-130 dollars. Official dealers can raise prices, and private workshops—on the contrary, say more loyal figures. The total amount of labour estimated when calculating the cost to replace the rear main seal is 30 hours. Therefore, depending on the kind of workshop the car owner chose and the time spent on the work, the cost in expenditure ranges from 600 to 3000 U.S. dollars.
To get an objective financial estimate of crankshaft oil seal replacement, it is recommended that you contact several auto repair shops, from official dealerships to mechanics advised by experienced drivers in the network.
How to replace the rear main oil seal
Depending on the type of oil seal used in the car, the algorithm of actions and preventive check engine seal replacement cost may differ.
So, replacing one-piece rear main seals will require dismantling the gearbox and flywheel and checking the crankshaft for damage. If there are not even large deformations on the unit, they must be eliminated. After the crankshaft is put in order, you can install the seal. The work is performed with the help of a special tool. The depth of installation is a value prescribed by the manufacturer of the part, which must be adhered to. After completing the work, it is necessary to return to the place of the gearbox and flywheel.
In the case of rubber main seals, which consist of two parts, the replacement algorithm will be a little more complicated and longer since it will require more attention to preparing the seal for installation. In particular, on the sealing element, as well as on the main bearing cap, engine oil is applied, as well as sealant. Special compositions help to more reliably and tightly fix the seal, ensuring its reliability and durability. With this type of seal, it is not necessary to dismantle the gearbox. It is enough to disassemble the lower part of the engine.
Cable rear main oil seals are installed on very old cars, which are no longer practically found on modern roads. But, if this is the type of oil seal caught on the auto, then its replacement will take place by the following steps:
- dismantling of the oil pan, pump and rear main cover
- removal of the old cable material, inspection of the crankshaft and repair of the unit if necessary
- preparing the oil seal for installation by inserting the rope into the groove of the block and rear main bearing cap
- trimming the rope to level with the rear main bearing cap and block
- swabbing the ends of the seal and cover and applying sealant to the cover
- tightening the cover according to the manufacturer’s recommendations.
The final step is the reassembly of the lower engine.
Watch this YouTube video to see a demonstration of how it’s done.
Frequently asked questions about the cost of replacing the rear main seal
Is it worth fixing a rear main seal leak?
Whether a rear main seal leak is worth fixing depends on several factors, such as the extent of the leak, the vehicle’s age and condition, and the cost of the repair.
A rear main seal leak can be a serious problem because it can leak engine oil, leading to low oil levels and potential motor harm.
However, if the leak is minor and the vehicle is in good condition, it is not necessary to fix it immediately. Ultimately, whether to repair a rear main seal leak should be based on careful consideration of the factors mentioned above and a professional mechanic’s evaluation of the problem.
Can I drive with a leaking rear main seal?
You are not recommended to drive with a leaking rear main seal, as this can cause engine oil levels to drop and potentially lead to serious engine damage.
How do I check the rear main oil seal?
To check the tightness of the rear main seal, you need to check the following points.
- Check for oil on the ground
- Clean the area around the rear of the engine
- Check the oil level
- Find the oil leakage
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