Rear main seal replacement
Thread Starter
5th Gear
Joined: Oct 2024
Posts: 5
Likes: 2
From: Utah
Rear main seal replacement
I am a new owner of a C5 and I was told that the rear main seal needed to be replaced. The guy gave me a number to a shop who could do it for me. One day after he had the car the shop owner said it would be too difficult to replace the seal? He gave me the car back and i’m slowly leaking out oil all over my driveway. How much should I expect to pay for a rear main seal and is it really that difficult of a fix?
Pro
Joined: Apr 2023
Posts: 670
Likes: 358
From: Windsor, CT
Yes, it's a pretty involved fix. You need to pull the engine out of the car, or pull the transmission and torque tube out of the car. The transmission route is easiest.
If you have a manual transmission, this would be the time to replace the clutch.
Due to the amount of work involved, I wouldn't blink twice if a mechanic charging hourly labor rates quoted you $2000 to replace the seal.
If you have a manual transmission, this would be the time to replace the clutch.
Due to the amount of work involved, I wouldn't blink twice if a mechanic charging hourly labor rates quoted you $2000 to replace the seal.
Last edited by Markolc1981; Oct 16, 2024 at 12:11 AM.
Team Owner
Joined: Oct 1999
Posts: 31,976
Likes: 487
From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
If you google, a clutch swap if manual or torque converter change, it will give you an idea of the steps involved as all of it has to come out to replace the rear main seal.
I'd buy a rear cover with rear main seal, rear cover gasket, and a new rear cover. If the seal is leaking, the rear cover gasket maybe leaking and you don't want to do it twice. You can also find all 3 parts as a bundle for less than just buying the gaskets. If the car is a manual, I'd consider changing the clutch, and inspecting the bearings and couplers in the torque tube.
You may want to pull the intake and inspect the back of the motor as the oil pressure sending unit can cause a leak which runs down the back of the motor. Pulling the intake is much less work. The oil adapter plate above the oil filter which contains the oil temp sensor is also known to leak.
I'd buy a rear cover with rear main seal, rear cover gasket, and a new rear cover. If the seal is leaking, the rear cover gasket maybe leaking and you don't want to do it twice. You can also find all 3 parts as a bundle for less than just buying the gaskets. If the car is a manual, I'd consider changing the clutch, and inspecting the bearings and couplers in the torque tube.
You may want to pull the intake and inspect the back of the motor as the oil pressure sending unit can cause a leak which runs down the back of the motor. Pulling the intake is much less work. The oil adapter plate above the oil filter which contains the oil temp sensor is also known to leak.
Last edited by 93Polo; Oct 8, 2024 at 05:12 PM.
