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Old 08-03-2012, 04:36 AM   #197
BergDonk OP
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Joined: Nov 2010
Location: Snowy Mountains Oz
Oddometer: 3,273
Countershaft Seal

As mentioned above I was supposed to heading to Queensland right now, but failed, and am now back home

Rode the DR to Sydney on Weds, now Fri, to meet up with Tim who was heading to the OCR. My plan was to travel with him and meet up with a few others coming up from Vic at Hungerford, then on to Julia Creek, then separate, and while the rest kept heading north for Cape and the OCR, I would then head for Townsville solo and catch up with a mate then home. I expected to be away for 2 weeks, and no longer, as have family stuff to do in a couple of weeks. I expected to do 6-6,500 kms and didn't have time to get to the OCR this time.

Prior to the off, I did the usual service and once over which this time involved a new chain and countershaft sprocket, a new cush drive bearing, and fresh oil.

I had previously noted the counter shaft seal starting to weep just a smidgen, so I changed it last week before I did the oil change. I knew it was coming, and had a fresh seal in the shed waiting. And because I knew I would be changing it, had another as well, so as to have a spare just in case after the change. I figured 47,000 kms for a cs seal was OK too.

I did the seal swap easily enough, bash the one in situ a bit to shrink the outer and lever it out, as I've done numerous times in the past on other bikes. All good. Press in the new seal with a large socket so it sitting just right, with the outer face in line with the bevel in the housing. No leaks, confirmed by a test ride. The ride was also the warm up for oil so I could dump it. Fresh Delo 400, and a filter, and good to go.

So loaded up the bike Tuesday, and ready for the off Wednesday. Out to the shed after the frost melted with plans to head to Sydney the back way. Roll the bike out of the shed, lock the shed up, and kiss SWMBO goodbye. It was her one morning off a week from work. I fired up the mighty DR and killed the choke after 15 secs or so like normal, and clicked into gear and off. A couple of seconds later, my attention was drawn to SWMBO yelling STOP, STOP, STOP.

What had I forgotten?

"Look down" she said. There was a large puddle of oil. "Bummer" I thought, "What's broken now? What have I stuffed up?"



Above is a pic of the oil trail. Bike was started on the concrete where most of the oil was dumped, but cleaned up before the pic.

'Hmmmmm, popped the cs seal" I suspected.

Rolled back into the shed and sure enough, the cs seal had popped. What to do? I pushed the seal back in, and wondered. I put 4 'dabs' epoxy metal on it to act as a keeper, and a couple of old seals I had lying about with the same ID. My thinking was that if it popped again, at least it couldn't fall out like it'd just done. Top up with 500 ml of oil and head north, and hour later than planned. No worries, just go a more direct route, and keep looking down at my left foot.

And wonder what might have been if my wife hadn't been there to wave me off. Fried engine? Crash on the twisties outside my gate with a rear tyre covered in oil

Stopped and checked it a couple of times enroute, and no problems, so one of those things?

Met up with Tim as planned, and next morning, Thursday, yesterday, 08.00, and we are off. I needed to top up with fuel, so 10 kms or so up Windsor Road, pull in to the servo, fuel up and have a look at the cs sprocket area and it wet with fresh oil.

BUGGER

So it seems that on 2 consecutive cold starts, the new seal has popped. Not catastrophically this time as my old seal spacers had worked as intended, but what to do? Tim said there was a bike shop a bit up the road at Windsor, so we pulled in there. I had the sprocket cover off, and the cs sprocket off just as the service manager for Hawkesbury Honda, Eric, came over to see what was going on. I had my back up fresh seal with me, and he seemed impressed. He took control, and I watched. After some discussion and checking, he inserted the new seal, commenting that it seemed to go in too easy. Fired it up, and all good.

What now concerned me was that we were heading over the mountains, west and north, and further away from help, spares, and my shed. I didn't have another cs seal, and what if it popped tomorrow on the next cold start. And why was it popping on cold starts?

Seals can pop from too much crankcase pressure which is something that happens at higher revs. This had gone with a cold engine at just over idle revs. A check of the oil flow diagram by Eric confirmed that the cs area gets pressurised oil.



You tend to get max oil pressure when the oil is cold, so, dunno? No issues with the housing in the case, as confirmed with Eric, and using Suzuki genuine seals. Eric checked the crank breather too, and all good, so WHY?

I sent Tim on his way solo and headed south for home, keeping an eye on my left foot.

Cruising down the Hume in case I needed mobile phone contact to call SWMBO to come and get me, I contemplated the problem, and kept an eye on my left foot.

I decided I would manufacture a seal 'keeper' so it couldn't pop again. I called in to Dahlitz in Queanbeyan and ordered a couple of new seals and then headed over to Fyshwick to get some 90 mm nylon bar. Cruising the Hume, I had developed a plan.

I arrived home about 17:30, and surprised SWMBO when she got home a few hours later.

Out to the shed this morning and unload the bike, then have a good look, and refine the plan.



Above you can see that the second new seal was still in place and there is some evidence of the 'dabs' of epoxy I'd applied, that had mostly 'gone walkabout'.





Above is similar pic, but if you look closely, you can see the old seal spacers I put in place, just in case.





Above is the cardboard template, then a version in 2 mm Al sheet, and then a slighlty different version, and hopefully the final one, Al in 3 mm sheet. Right to left.





Above is the 3 mm version bolted up. I've used the top 2 bolts from the gear shift cover, and the rear crank case bolt. A bit tricky getting all the spacers the right length. The crank case bolt is actually replaced with a stud I made up. Everything seems like it'll clear the chain, and the cover bolts up like normal.

Tomorrow, I plan to machine up some nylon that'll attach to the plate and lock the seal in place.

In summary, with nothing other than a fresh cs seal and oil it now pops them on a cold start. The oil is the same I've been using in it for the last 40,000 kms. I don't want to glue the seal in because that can be problematic when I have to change it later. I also recall that the big DR thread has had reported a few cs seals popping too, but I don't recall any analysis, or what the posters did to fix it.

More to come.
Steve
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BergDonk screwed with this post 08-04-2012 at 01:33 AM
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