Small oil leak on my R1150GS final drive, crown wheel seal or input seal?

[casparv]

Hi everyone,

I’m looking for a bit of advice about a small oil leak on my 2001 BMW R1150GS (around 100,000 km). The bike runs great and recently had the final drive bearings replaced last summer. However, there’s now a light oil leak on the left side of the final drive housing, near the rear wheel and brake caliper area.

At first, I thought it might be the input shaft seal (right side), but since the oil seems to come from the left side, I suspect it’s the crown wheel oil seal instead. The gaiter on the right is dry, and there’s no oil around the swingarm joint.

Has anyone seen this after a bearing replacement? Could the crown seal have been disturbed or over-pressurized during reassembly? Any recommended brands or tips on what this could be exactly?

Thanks in advance, I’m trying to confirm the exact cause before tearing into it.

Regards.

Caspar

x

 

[Paul Young]

Hi everyone,

I’m looking for a bit of advice about a small oil leak on my 2001 BMW R1150GS (around 100,000 km). The bike runs great and recently had the final drive bearings replaced last summer. However, there’s now a light oil leak on the left side of the final drive housing, near the rear wheel and brake caliper area.

At first, I thought it might be the input shaft seal (right side), but since the oil seems to come from the left side, I suspect it’s the crown wheel oil seal instead. The gaiter on the right is dry, and there’s no oil around the swingarm joint.

Has anyone seen this after a bearing replacement? Could the crown seal have been disturbed or over-pressurized during reassembly? Any recommended brands or tips on what this could be exactly?

Thanks in advance, I’m trying to confirm the exact cause before tearing into it.

Regards.

Caspar

x

Message says the ‘content is not viewable
In your region’ so unsure what you’re describing, but fluid near the calipers could be from the FD breather or from the caliper. It doesn’t travel ‘uphill’ so my suggestion would be to just look above where you’ve seen the evidence.

 

[casparv]

Message says the ‘content is not viewable
In your region’ so unsure what you’re describing, but fluid near the calipers could be from the FD breather or from the caliper. It doesn’t travel ‘uphill’ so my suggestion would be to just look above where you’ve seen the evidence.

Can you see it via this link? https://drive.google.com/file/d/1ImUJ_0aE8Weya_le4dGIbHPjvaJ4by97/view

 

[Paul Young]

Can you see it via this link? https://drive.google.com/file/d/1ImUJ_0aE8Weya_le4dGIbHPjvaJ4by97/view

That worked. That looks like it’s leaking from the gaiter so have you looked inside?

 

[casparv]

That worked. That looks like it’s leaking from the gaiter so have you looked inside?

Just checked inside my guess than it is my input seal right?

IMG_7750.jpg

drive.google.com

IMG_7754.jpg

drive.google.com

 

[Paul Young]

…or weeping from the back of the gearbox.

 

[Steptoe]

Instead of the guess work from a picture we can’t see .. take the rear off and see it’s leaking from the final drive flange seal.
And pull the gaiter back and see how much oil is inside the gaiter.

You mention could the output/wheel flange oil seal got damaged during reassembly after replacing the large final drive bearing …. You fit a seal if changing the final drive bearing .. you insert the seal after reassembly,