2011 GS ADV | (Rear Main Seal Leak - 130K)

[venturer434]

Hello Everyone, 

 

Supporting a fellow rider trouble shoot/ fix his 2011 GS ADV specific to Rear Main Seal (RMS) Leak. 

 

History (Rear Main Seal (RMS)).

1. First Failure at occurred at 50K miles - Fixed

2. Second Failure Noticed at 130K miles - Pending fix

 

Questions:

1. What are some of the main causes for the RMS failure?

2. Engine Ventilation system check suggestions if any ?

3. Any suggestions/tips to investigate in to prior to start of the fix to better understand the reasoning behind the failure?

 

 

 

 

[dirtrider]

49 minutes ago, venturer434 said:

Hello Everyone, 

 

Supporting a fellow rider trouble shoot/ fix his 2011 GS ADV specific to Rear Main Seal (RMS) Leak. 

 

History (Rear Main Seal (RMS)).

1. First Failure at occurred at 50K miles - Fixed

2. Second Failure Noticed at 130K miles - Pending fix

 

Questions:

1. What are some of the main causes for the RMS failure?

2. Engine Ventilation system check suggestions if any ?

3. Any suggestions/tips to investigate in to prior to start of the fix to better understand the reasoning behind the failure?

 

Afternoon  venturer434

 

First off, you need to verify that is really is the rear main seal that's leaking. It is usually more likely to be a leaking rear accessory shaft/balance shaft seal.   

 

If it is the rear main seal leaking then check for rear main bearing wear as rear main bearing wear allows the rear of crankshaft to move around in the seal.

 

Also check for pinched crankcase breather hoses.

 

Don't get ahead of yourself in finding the problem, find out EXACTLY where the seep or leak is coming from, such as at the seal lips, or at the seal perimeter, or possibly at the crankcase seam, or even coming from higher up & running down. (maybe even an oil galley plug or cam chain pin)

 

It's a LOT of work to guess at the leakage point then have to go back in again at a later date due to mis-guessing the first time.  

 

 

 

 

 

[venturer434]

On 6/9/2021 at 8:36 AM, dirtrider said:

Afternoon  venturer434

 

First off, you need to verify that is really is the rear main seal that's leaking. It is usually more likely to be a leaking rear accessory shaft/balance shaft seal.   

 

If it is the rear main seal leaking then check for rear main bearing wear as rear main bearing wear allows the rear of crankshaft to move around in the seal.

 

Also check for pinched crankcase breather hoses.

 

Don't get ahead of yourself in finding the problem, find out EXACTLY where the seep or leak is coming from, such as at the seal lips, or at the seal perimeter, or possibly at the crankcase seam, or even coming from higher up & running down. (maybe even an oil galley plug or cam chain pin)

 

It's a LOT of work to guess at the leakage point then have to go back in again at a later date due to mis-guessing the first time.  

 

 

 

 

 

Morning dirtrider, 

 

Thanks for the detailed suggestions/investigation tips.. we will look into it closely and take it step by step.