1999 5.9 cummins rear main seal replacement

Bottom line is, almost any other cause for oil leak is cheaper to repair than replacing the rear main seal. The leak at the rear of the oil pan gasket is often confused with a rear main seal leak, so inspect it thoroughly to rule it out. Valve cover gasket, intake manifold gasket, and distributor gasket should all be ruled out, especially if you find oil dripping on the top of the bell housing. This is not a definitive sign, as leakage from other components may drip down towards the bell housing and lead you to a false conclusion. The location of the rear main seal leak will be at the bottom of the transmission bell housing, where it comes in contact with the engine. However, with how expensive the rear main seal is to replace, you should rule out everything else before making a conclusion.

Oil consumption and forming of oil puddles underneath the vehicle can signal early-stage failure of the rear main seal. Symptoms of a Bad Rear Main Seal Oil Leaks What’s special about the rear main seal is that it’s very difficult to gain access to, and requires you to remove the transmission, and sometimes even the engine. The seal is just like any other synthetic rubber ring and prevents the oil seal within the engine, and it’s made very durable to last as long as possible. In longitudinally mounted engines, the seal is located towards the back of the engine bay, while transversely mounted engines have the seal facing the left or right wheel arch. The rear main seal can be found at the rear end of the engine, where it connects to the transmission.

Mechanics will charge between $500 and $1800 for the labor alone, with the average total cost of repair being $1100. Even though the parts won’t cost more than $100, the cost of labor is what makes the rear main seal repair very expensive. The main symptom of the rear main seal leak is forming an oil puddle beneath the spot where transmission and engine are merged.

Considering just how important oil is for the healthy operation of the engine, any leaks need to be addressed as soon as possible. Moving your vehicle on the driveway only to find a small puddle of oil left behind is a serious reason for concern.

1999 5.9 cummins rear main seal replacement