Left crankshaft oil seal

**jetmechmarty** · 06-05-2025, 09:20 AM

AT-205 RE-SEAL by ATP Automotive will stop the crankshaft seal leak. You can use that stuff until you resolve seal replacement. The stuff works as long as you’re using it. You add it to the oil.

**bikerphil** · 06-05-2025, 10:22 AM

Here is a thread discussing the changing of the left side crankshaft seal....

https://xs11.club/forum/idle-talk-forum/xs11-xj11-discussion/868577-oil-on-the-good-foot

**Appie** · 06-05-2025, 11:13 AM

Originally posted by jetmechmarty

AT-205 RE-SEAL by ATP Automotive will stop the crankshaft seal leak. You can use that stuff until you resolve seal replacement. The stuff works as long as you’re using it. You add it to the oil.

Thanks Jetmechmarty! I never thought of an additive… We don’t have AT 205 here but we do have equivalents that I can use while I get to know this bike. Does it thicken the oil? I have a cb 650 and thinking of those pinhole oil valves through the block to the camshafts I get nervous.

**Appie** · 06-05-2025, 11:20 AM

Originally posted by bikerphil

Here is a thread discussing the changing of the left side crankshaft seal....

https://xs11.club/forum/idle-talk-fo...-the-good-foot

How did I miss this? Thank you bikerphil, back to the drawing board. I’ll post with feedback as soon as possible. I appreciate the help.

You guys are legends!

**jetmechmarty** · 06-05-2025, 01:35 PM

Originally posted by Appie

Thanks Jetmechmarty! I never thought of an additive… We don’t have AT 205 here but we do have equivalents that I can use while I get to know this bike. Does it thicken the oil? I have a cb 650 and thinking of those pinhole oil valves through the block to the camshafts I get nervous.

AT-205 will not thicken oil. It softens that rubber seal riding the crankshaft. It is the only product of its kind that I have used that actually works. All bets are off on anything else where I’m concerned.

**speedlimit85** · 06-05-2025, 07:19 PM

left has an outer diameter of 48mm right is 45

**Appie** · 06-06-2025, 12:41 AM

Originally posted by jetmechmarty

AT-205 will not thicken oil. It softens that rubber seal riding the crankshaft. It is the only product of its kind that I have used that actually works. All bets are off on anything else where I’m concerned.

Thanks for explaining that for me. And in thinking about a substitute I fully agree. Better to try and source something that has been tried and tested on this forum.
I really don’t want to start a new topic ‘So I put this additive in my oil and….’ 🥴

**Appie** · 06-06-2025, 01:50 AM

Originally posted by speedlimit85

left has an outer diameter of 48mm right is 45

Thanks speedlimit85! Not what I was hoping for but I do have other options now thanks to you guys. I was reading that the crankcase needs to be split to replace the original seal anyway which is beyond my pay grade at this stage.

**jetmechmarty** · 06-06-2025, 08:13 AM

Originally posted by Appie

I was reading that the crankcase needs to be split to replace the original seal anyway which is beyond my pay grade at this stage.

I have yet to replace that seal, but I don’t believe splitting the cases is necessary, particularly with an aftermarket seal.

**DiverRay** · 06-06-2025, 09:32 AM

The OEM seals are no longer available, so you CAN replace it without splitting the cases. The hard part is getting the old seal out as you will need to remove the lip that is "locked" in the case, but it is doable. Just be careful of the crank as you work the old seal out.

**jetmechmarty** · 06-06-2025, 11:14 AM

Originally posted by DiverRay

The OEM seals are no longer available, so you CAN replace it without splitting the cases. The hard part is getting the old seal out as you will need to remove the lip that is "locked" in the case, but it is doable. Just be careful of the crank as you work the old seal out.

Perhaps a sheet metal screw and a Vise Grip plier is appropriate for that job?