Oil leak identification, just below tach cable on head?

[Bendrider]

Hello GS riders,
I have an oil leak that is coming from what I believe to be below the tack cable installation into the head. It looks like it’s coming from a bolt that’s behind and under the tack cable mounting point. Is anyone else dealt with this problem? I used UV dye in the oil in a black light that’s why everything looks funky green.

[Burque73]

I'll bet it's the O-ring on that sleeve or the seal around the Tachometer drive thingy that's leaking, they always leak eventually. It's pretty easy to pop that sleeve out and replace the seals. I went ahead and ordered a new sleeve, oil seal, drive thing and O-ring when I did mine. The sleeve sometimes breaks off when prying it out. No worries if you're prepared with a new one.

Maybe time that repair with your next valve clearance check as it helps to have the cam cover off.

[Bendrider]

I'll start with that repair and see how it goes...

[bwringer]

Ze instructions:

https://www.bwringer.com/gs/tachcableseals.html

Crikey, I last updated this page in 2004. So yeah, uh, this is a problem that's been around a while. Fortunately, it's an easy, cheap fix.

[steve murdoch]

Thanks, bwringer.
Close to twenty year old repair tutorial that is just as effective today as it was back then.

[Burque73]

I'll start with that repair and see how it goes...

I was looking through my pics and found these from a repair I did a while back. This was a GS1100GL, but you'll have a similar setup.

If that sleeve does break off, here's what to expect and how to get through it.

Mine snapped off flush with the head while prying on it.

1100 broken sleeve by Roger, on Flickr

I clamped onto the end of the drive thing and pryed on the vice grips, being careful not to damage any cooling fins on the head of course.

1100 removing tach gear by Roger, on Flickr

That marred up the drive pretty badly, but it didn't matter since the new part was on hand.

1100 tach gear with sleeve by Roger, on Flickr

[93Bandit]

I was looking through my pics and found these from a repair I did a while back. This was a GS1100GL, but you'll have a similar setup.

If that sleeve does break off, here's what to expect and how to get through it.

Mine snapped off flush with the head while prying on it.

1100 broken sleeve by Roger, on Flickr

I clamped onto the end of the drive thing and pryed on the vice grips, being careful not to damage any cooling fins on the head of course.

1100 removing tach gear by Roger, on Flickr

That marred up the drive pretty badly, but it didn't matter since the new part was on hand.

1100 tach gear with sleeve by Roger, on Flickr

Oh wow, thanks for posting this info. This is exactly what happened on my 850L when I attempted the leak. I didn't have a new one on hand and assumed I would have to pull the valve cover to fix it, so I smeared it with RTV and bolted it back together for a rainy day. That was Sept of 2017. There's been a lot of rainy days since then!

[Burque73]

Oh wow, thanks for posting this info. This is exactly what happened on my 850L when I attempted the leak. I didn't have a new one on hand and assumed I would have to pull the valve cover to fix it, so I smeared it with RTV and bolted it back together for a rainy day. That was Sept of 2017. There's been a lot of rainy days since then!

You're very welcome.
It's probably good that there have been lots of rainy days to help wash your engine since I can't imagine the RTV worked all that well. LOL

[93Bandit]

You're very welcome.
It's probably good that there have been lots of rainy days to help wash your engine since I can't imagine the RTV worked all that well. LOL

It actually worked better than I expected. Didn't start leaking again until late last year. But I've only put maybe 5k miles on it since I broke that part.

As for rainy days, I try to avoid riding in the rain.

[Grimly]

Mine started leaking but a new set of seal and o-rings only brought a temporary (two years ) relief.
Unfortunately, a supplier of NOS tacho drives had run out of them, so as a stop-gap measure I removed the internal shaft and plugged the hole entirely with RTV, and just rode tacho-less for a few months.*
Eventually I found a good used tacho drive, which is still going strong.
The problem is the road dirt grinds a notch in the shaft where the seal meets it, making the life of a replacement seal quite short.

*At that point I bought an electronic tacho, but haven't fitted it yet.

[bwringer]

Grimly, mine hasn't leaked since I documented the repair 20-ish years ago... I did replace the geared shaft at that time, though, because the old one had a worn groove. WIth a tach cable in place, it's hard to see how any dirt could get in there.

One trick for dealing with grooves on sealing surfaces you can't replace is to not install the seal all the way, so that the seal rides on a fresh surface. This is often not easy to do, but perhaps something as a spacer in the bore, maybe an o-ring, would help keep the seal 1 or 2mm further out.




Another detail that may be useful for someone somewhere: if you go to an electronic tach or eliminate the tach, there's a plug from this hole that was used on several GS models with a factory electronic tach. It uses the same seal band as the tach drive fitting. A much neater solution than RTV...

The Suzuki part number for the plug is: 26442-45000

https://www.onlinecycleparts.com/oemparts/partsearch/suzuki?partsearch=26442-45000

It was used, among several others, on the 2005 GS500 and is in the cylinder head fiche.

[bobgroger]

If the tach drive seal doesn't work check the valve cover gasket. If it leaks in the right spot it conveniently drains out that hole below the tach cable.