New Season, Same Problem!

[chewy999]

Been a bit quiet on the forums over Winter, but as the weather gets 'warmer', doing the jobs I'd set to get ready for riding. Over the Winter I started her up once in a while to make sure all is well, always started well considering I drained the carbs each time, and didn't even have to put the battery on charge. Maybe it wasn't as cold as I'd thought!
Anyway, on one start, I noticed the tell tale sign of an oil leak, (drips on the floor), and yes, it's coming from the crankshaft seal, again.
Those of you that follow my attempts, will remember that I've had real problems trying to sort this out, but for some reason, I just cannot get it fixed. I have replaced the seal several times and even put a sleeve on the crankshaft which I thought had finally done the trick, but obviously not!

I took the radiator off to make more space, covers off and wiped the timing belt area and started up, after connecting a hose in place of the rad, and looked for the leak. No leak!!! I did check the oil level which was very low, just below the lower mark, so put a little oil in and checked again. Leaking again. Obviously not good to ride with low oil.

Going to try again, got a couple of ideas including using a thicker oil, and maybe not push the seal in so far, but apart from that I'm at a loss (again)!

Will keep you informed.

[flyin900]

Chewy,

Where’s is it leaking from the shaft or the seal area around the case?

[chewy999]

Chewy,

Where’s is it leaking from the shaft or the seal area around the case?

I've always assumed it was the seal around the shaft, but hard to tell with the belts in place. Once I put some powdered chalk over it so I could see where the oil was coming from. Seemed to show I was right in my assumption, but will try again. Thought about putting some sealer around the outside of the seal just in case. I have been wrong before! (Many times)

[flyin900]

Chewy,

Just some thoughts and the reason I was asking is if it is leaking from the shaft area.
It maybe an issue with the shaft not running linear and the runout is causing the seal to leak. A dial gauge would indicate runout on the shaft, so if you can possibly borrow one or a tool rental place maybe able to help there.
If it is from the case area then that should be an easier fix with some appropriate sealant used judiciously around the area and I believe you installed a shim in there too.
Normally the stock seals don't seem to be an issue though, so something is causing the continued weeping of the oil. Possibly it was damaged when it was installed the last time with the other shim part? The shim maybe also allowing a path since you now have two sides to seal with the shim if it is on the outer part of the seal and case area.

[Whiskerfish]

Were the cases of this engine ever split?

[chewy999]

Were the cases of this engine ever split?

Yes they were as I had a leak on the bottom of the engine when I got the bike. If I'm right about what you're thinking, I'm sure it's not leaking from the casing.

[chewy999]

Chewy,

Just some thoughts and the reason I was asking is if it is leaking from the shaft area.
It maybe an issue with the shaft not running linear and the runout is causing the seal to leak. A dial gauge would indicate runout on the shaft, so if you can possibly borrow one or a tool rental place maybe able to help there.
If it is from the case area then that should be an easier fix with some appropriate sealant used judiciously around the area and I believe you installed a shim in there too.
Normally the stock seals don't seem to be an issue though, so something is causing the continued weeping of the oil. Possibly it was damaged when it was installed the last time with the other shim part? The shim maybe also allowing a path since you now have two sides to seal with the shim if it is on the outer part of the seal and case area.

Thanks for that. FYI it's a sleeve on the shaft and not a shim. That said it may be leaking from the shaft/sleeve 'gap', although it was an interference fit. The instructions said no sealant was needed, but maybe I should it give another (one last) try. The sleeves are not to expensive.

https://www.ebay.co.uk/itm/99819-SKF-Sp ... 4d4cdc8c16

I'll also try to find a dial gauge to check the crankshaft, but (with the naked eye) it looks ok!

[flyin900]

So there was an issue with the output shaft requiring that sleeve to correct a problem? Was there pitting on the shaft area? If so then if that is still there the oil could find a path out if the pitting wasn’t cleaned up.
Also if the OEM seal is a single lip design possibly there is an aftermarket piece of the same sizing that will offer a double lip design for added protection.
I think the first order is to determine where it is leaking from and go from there.

[5speed]

are you running synthetic oil chewy?
Not sure if this is truth or fiction but I've heard engines that ran dyno oil and get switched to synthetic will sometimes develop leaks where there were none before.

[chewy999]

So there was an issue with the output shaft requiring that sleeve to correct a problem? Was there pitting on the shaft area? If so then if that is still there the oil could find a path out if the pitting wasn’t cleaned up.
Also if the OEM seal is a single lip design possibly there is an aftermarket piece of the same sizing that will offer a double lip design for added protection.
I think the first order is to determine where it is leaking from and go from there.

There didn't appear to be any pitting to speak of, but I'd tried several seals with no luck and sleeving was another option. Thought I'd cracked it as there were no drips on the floor for a while, but then after about the third start up over the Winter, it started again. As for the seal itself, get them from David Silver and are double lipped. When I get time, will have a look and report back, but don't hold your breath! Thanks for your advice so far.

[chewy999]

are you running synthetic oil chewy?
Not sure if this is truth or fiction but I've heard engines that ran dyno oil and get switched to synthetic will sometimes develop leaks where there were none before.

I've read several articles suggesting that, but not sure if it's an urban myth. In my (little) brain, if you have a leak, liquid will seep out. If all is secure, it won't! That said, they say antifreeze will find a gap where there was none before.
Fyi I've just bought some thicker oil, 20-50, to cover all bases.

[robin1731]

are you running synthetic oil chewy?
Not sure if this is truth or fiction but I've heard engines that ran dyno oil and get switched to synthetic will sometimes develop leaks where there were none before.

Not true. Unless you are running 0w oil. Which they do make. I've switched plenty of engines over and never had issues with normal weight oils.

.

[gltriker]

Did you utilize a seal protector to install the double lip seal?

Greatly reduces the probability of rolling the inner seal lip under itself when starting the double lip seal onto the shaft.

[5speed]

are you running synthetic oil chewy?
Not sure if this is truth or fiction but I've heard engines that ran dyno oil and get switched to synthetic will sometimes develop leaks where there were none before.

Not true. Unless you are running 0w oil. Which they do make. I've switched plenty of engines over and never had issues with normal weight oils.

.

I didn't have any problems when I switched my camaro to mobil 1 but I read it on the interweb..so it must be true right?

[chewy999]

Did you utilize a seal protector to install the double lip seal?

Greatly reduces the probability of rolling the inner seal lip under itself when starting the double lip seal onto the shaft.

I used an old microfiche over the crankshaft from a tip I found somewhere on this site. If someone could confirm how it should be done that way I would appreciate it, I just wrapped the fiche around the shaft, fed the seal on after smearing engine oil on the seal itself, and tapped it in place using a large piece of pipe. The pipe was a fraction smaller than the OD of the seal body.