How to Replace Rear Main Seal Chevy 350?

You must be an antique car lover for having an engine like Chevy 350 installed in your car. The classic sort of car that is nearly extinct in many developing countries.

Right now, the world is rocked by cars like Tesla, Ferrari, Lamborghini, Ford, BMW, and other special-looking modern cars. Camaro and Mustang also got new designs and structures like modern cars.

But once the Chevy 350 was the most popular engine in the late 1970s and 1980s for Camaro and Corvette.

An engine like this requires a lot of attention. And we know that you are looking for how to replace rear main seal Chevy 350.

It’s not a difficult task even though Chevy 350 is an engine from 1967. So, let’s not waste a drop of second here and get to know how to replace 1 piece and 2 piece rear main seal Chevy 350.

What cars had a Chevy 350 engine?

As we have mentioned earlier that the Chevy 350 was launched in 1967. You could find it on any Camaro and Corvette cars you touch. The first car it got installed on was a 1967 Camaro.

From 1987 to 1992, the engine was used in a lot of Malibus, Pontiac Firebird, and Impalas cars.

And from the 1980s to the early 1990s, it was the most used engine for the Chevy Police Cruisers just like how the 1991 Caprice was.

It was a small block engine, but a powerful one. The stock car racers named it ‘Mighty Mouse’. 

How to replace rear main seal Chevy 350

Even though the Chevy 350 was released in the 1960s, it’s still one of the best small block yet powerful engine out there. And we understand if you wanted to replace your current rear main seal with a new one due to a faster engine oil leak rate.

1 Piece Seal and 2 Piece Seal:

If your Chevy 350 has a 1 piece seal, then you have to remove the transmission on the engine, but if you have a 2 piece seal, then you don’t have to remove it. That was the basic difference here, all the other procedures are pretty much the same.

Oil Draining

To remove the rear main seal, you have to drain out all of the oil in the engine. You need an oil-free rear main seal to remove it.

Removal of the seal

You need to be careful while removing the seal. Beyond the seal, there is a seal retainer. You don’t want to damage that part. Firstly, drill two small holes on the opposite sides of one another and be careful not to touch the crank.

Now comes the tricky part. Take two screws with you and put them into those two holes. Once they are installed, try to pull out the seal by pulling those two screws.

You can remove the seal retainer once you’ve removed the rear main seal successfully. Although that’s not what you’re here for, right? So, let’s not focus on that.

Installation of the new seal

Now, take your brand new rear main seal and put it around the crank. Make sure the seal has been put down firmly. Otherwise, it could come off the crank. And be sure not to damage the seal or you’ll get the same result before replacing the seal, which was excessive oil leaking.

Take your seal installation tool and place it right above the seal. Pick a hammer to tap the tool down for setting up the seal. Tap gently to put the seal down evenly. Once the seal in being installed firmly, try to tap the corners so no leakage is visible anymore.

Alright, now our seal is firmly seated and flushed with the house and that’s all we need to do.

Reinstalling the flexplate and transmission

If you had a 1 piece seal, then you have to follow these instructions. Remember when you removed the transmission. You can’t just leave it out, right?

Reinstall the flexplate and transmission into the engine again and now you are good to go. And when you are a 2 piece seal user, you were good to go from the earlier section where we installed the new seal.

Chevy 350 Rear Main Seal replacement cost

Chevy 350 rear main seal isn’t something you can get for cheap. Chevrolet items were always expensive, and the Chevy 350 wasn’t an exception.

The estimated cost of a rear main seal would be 600 US dollars to 900 US dollars. A rear main seal of Chevy 350 would cost over 1300 US dollars. 

The service fee is also expensive. Normally car repair shops charge 550 US dollars to 820 US dollars. So, the total cost of replacing a Chevy 350 rear main seal would be more than 2000 US dollars.

You can deduct the repair cost by replacing the seal all by yourself. Although it engages so much risk.

Is it worth replacing rear main seal?

If you experience excessive leakage of oil from your car and you kept running short on oil every time, then it’s necessary for you to replace your damaged rear main seal.

We are aware that the cost of replacing a rear main seal is pretty expensive. But when you look at the bigger picture, you will notice that you have to buy oil more than ever due to the faster oil draining rate.

Sometimes, you could get them for a cheaper price but sometimes you may go bankrupt buying only oil for your Chevrolet car.

So, now you should reconsider whatever your opinion was on: Is it worth replacing rear main seal?


A damaged Chevy 350 rear main seal can be a real pain in the back, but replacing the rear main seal could be more painful.

Either way, we are destined to spend a lot of money on this. At least our guide on how to replace the rear main seal Chevy 350 will help you minus about 550 US dollars to 820 US dollars.

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