1999 5.9 cummins rear main seal replacement

Just like every other mechanical component, some signs and symptoms will pop up to notify the driver of a defective or leaking rear crankshaft seal. The location of this seal makes detecting and fixing an oil leak challenging and complicated. Driving with a rear main seal leak can be very dangerous and can lead to total engine failure. The seal wears out over time as a result of corrosion from road salt, crankshaft rotational forces, and other environmental factors. The rear crankshaft seal is usually made of silicone or rubber. Engine oil leak from the rear crankshaft seal is hard to diagnose, except if you’re a gearhead like me because the oil usually drips from where the transmission connects to the engine and drips elsewhere, such as the crankcase.

On front-wheel cars, the engine is typically mounted diagonal, so the back of the engine is the side opposite the one with idler pulleys, tensioners, and the serpentine belt. It is an expensive fix because, most times, it requires removing the transmission or dismantling the engine. What is a rear main seal, and how does it work? The rear main seal is found at the back of the engine between the engine and the transmission, which seals the crankshaft’s back end from leaking.

So, in this article, we’ll discuss at length the signs of a rear main seal leak, what causes a rear main seal leak, and how to replace it.

It can cost you $600 to $900 or more at a dealership. For many car owners, such news could cause a bad day because the rear main seal replacement is one of the most expensive, most labor-intensive, and most-dreaded repair jobs to do on your vehicle. The primary cause of the rear main seal failure is rupture inside the engine or on a component connected to the engine. The rear main seal is one of the essential seals in your vehicle that you don’t expect to leak unless you’re dropping your engine or transmission because replacing this seal requires dissembling the engine or transmission before you can reach it. So, don’t be surprised when a mechanic tells you that the oil leaks from the rear main seal. Do you see oil puddles under your vehicle, especially when the engine is running? That might be one of the most noticeable rear main seal leak symptoms.

1999 5.9 cummins rear main seal replacement