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RISLONE Heavy Duty Rear Main Seal Repair

RISLONE Heavy Duty Rear Main Seal Repair

Regular price $35.30 AUD
Regular price Sale price $35.30 AUD
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Rislone Rear Main Seal Concentrate is specifically designed to seal rear main seal leaks, but it also works better than a conventional stop leak on all other leaks, including timing cover seals, cam seals, rear main seal, o-rings and other gaskets. Rislone Concentrated Rear Main Seal Repair is a unique combination of lubricity agents and conditioners that restores the seal to like new condition and also contains additives to stop leaks in severely worn seals and crankshafts.

Replacing the rear main seal in a vehicle incurs high labour bills, as replacement of the rear main seal in a front wheel drive vehicles usually requires the engine to be removed, and in a rear wheel drive the transmission usually needs to be removed.

  • Lubricates
  • Quiets Noise
  • Seals Rear Main, Cam Seal & Timing Cover Leaks
  • Restores Shrunk & Hardened Seals
  • Use in Petrol & Diesel Engines

Dosage & Directions 

1 bottle treats 3.5 to 6L of oil. Larger systems use 1 bottle for every 5L of oil capacity.

Add entire bottle of Rear Main Seal Repair to engine crankcase at or between oil changes. Do not overfill. Most leaks will stop within 150 km or 2 days of driving. To prevent future leaks, install Rear Main Seal Repair every 8,000 km or with every oil change.


Rislone Rear Main Seal Repair works with all petroleum-based motor oils including conventional, high kilometre and synthetic formulas.

Use in ALL 4, 6 and 8 cylinder vehicles, with petrol, LPG, Diesel, turbo or racing engines. Works in motorbikes/vehicles with a wet clutch system, however dosage is is 93ML/1L of oil.

Rislone Rear Main Seal is comapatible with Rislone Engine Treatment, Rislone Compression Repair and Rislone Oil Treatment..

If you are unsure what other additives could be in the oil system prior to adding Rislone, it is recommended to flush the system first.

Frequently Asked Questions

What is a rear main seal?
A rear main seal, also known as a main seal or rear main bearing seal is located between the engine and transmission. The crankshaft (the internal engine part that the pistons are connected to) sticks out of the rear of the engine, and the flywheel & transmission bolt to this crankshaft. The engine oil lubricates the crankshaft, pistons and other internal parts of the engine. The rear main seal is inserted into the back of the block and fits snug around the rear of the crankshaft and keeps the engine oil from escaping.

What are the symptoms of a rear main seal leak?
Depending on the severity of the leak the first thing you may notice is the oil level going down. The next thing that happens is spotting, where you will find oil spots, located on the driveway or garage. While looking under the vehicle around the area where the engine and transmission connect, you will find oil dripping, or an oil residue with dirt caked on this part of the vehicle, most noticeably under the oil pan and the front of the transmission. In some transmissions, it will actually be the oil leaking out of the front of the transmission. In some manual transmission vehicles, you may also notice some slipping of the clutch, which can occur with a leaking rear main seal.

What causes the rear seal to leak?
The most common cause of rear seal leaks is age and/or high kilometre. The seal can also leak due to the vehicle being stored for an extended period of time, or from running the engine low on oil. This causes drying and hardening of the seal leading to shrinking, cracking and tearing of the rear main seal.

What other factors can contribute to a rear main seal leak?
A few things can cause a rear main seal leak to worsen, which are not the fault of the seal itself. If the oil level is two high (filled over the full mark) or the PCV (Positive Crankcase Ventilation) system is not functioning correctly, leaks can occur. The PCV system prevents pressure from building up inside the engine and if it fails, the pressure will cause the oil to leak out. It is a good idea to clean or replace the PCV valve regularly to prevent this problem.

Do I need to use Rislone Rear Main Seal with every oil change?
No, we have found that you can receive good results if you reuse the product every other oil change.

How do you replace a rear main seal?
For most rear wheel drive vehicles the transmission is removed to replace the seal. On front wheel drive vehicles, it is usually easiest to remove the engine to gain access to replacing the seal. Either way, this is an expensive procedure.

What else can be done to stop a leaking rear seal other than replacement?
Rislone Rear Main Seal Repair is one of the only products of its kind on the market specifically designed to solve rear seal oil leaking problems. There are special oil additives on the market that are designed to swell the rubber of the rear seal and cause it to expand, thus sealing off the leak. You can also try using thicker weight engine oil, like 50 weight. The thicker oil can fill in the gap between the seal and the crankshaft, and could slow the leak down.

How does Rislone Rear Main Seal Repair work?
This product works in two ways to help solve most any seal type leak.

1) The seal restorer additive restores seal size, flexibility and elasticity lost due to engine heat, age and high mileage.

2) The seal polymer works by building a polymeric film around the rear main seal and also filling in any groove worn into the crankshaft by the seal.

What types of seals will Rislone Rear Main Seal Repair fix?
Because of the Rislone 2X Action formula, the product has additives to work on any of the three types of rear main seals, no matter what the material.

Will Rislone Rear Main Seal Repair work on other oil leaks?
Yes. Even though it is specially designed to seal rear main leaks, it also works better than a conventional stop leak on all other engine oil leaks. This includes the timing cover seal, cam seals, O-rings and other seals and gaskets.

Will Rislone rear Main Seal Repair clog my oil filter?
No. Unlike our cooling system products, Rislone Rear Main Seal Repair has no particles to plug the leak. It contains special polymers and seal conditioners to stop seal leaks.

Technical Information

CODE: 44240

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