Hello again – as promised a blog post about this Ducati 916 swinging arm bearing, pivot/pin that we had some issues with. This might be a long one, so please do bookmark this page.
The story started off with a customer of our who booked his bike in for an annual/routine service, and an MoT.
During the MoT test, the tester noticed the rear suspension not working as it should – it was pretty stiff. This then followed by Terry, our track day expert, testing the rear suspension (he knows his way around what a bike should feel like!), and it didn’t budge at all.
This then followed by Terry taking a seat on the bike, myself on the pillion seat and both of us bouncing on the bike whilst Simon hold it upright – not even an inch on movement, so we imagined the rear shock absorber was totally seized solid!
Having rang the customer, he approved for us to remove the shock absorber to take a closer look – and we proceeded.
But there was only one issue – as you remove the shock, you need to support the swingarm, so as it does not drop down. Of course, we had it all secured, but the swingarm didn’t move much – soon as you remove the shock, there should be nothing holding the swinging arm up, except for the pivot pin/bolt, so it should simply drop.
That’s where the problem was.
Magically, a swingarm floats, as per above pics.
The swingarm wouldnt budge at all – having done a quick internet search, we found various online forums where people just seem to argue and talk about horsepower and cylinder porting, and not many have the solution. Drilling and hammering parts is the *last* resort, according to most workshops and technicians, and it is for us too!
So we got out some tools, only to get some bad results..
A few slight hammer taps and still not going anywhere, so we got the big boy tools onto it. Below you will see a spring compressor adapted to suit the situation at hand.
It still didn’t want to budge. It got to the point where there was strain on the flat parts of the spring compressor.
Simon is very handy with a lathe, and welding equipment (well, he did build a few bikes – check out the 48 cylinder for a good example of his work!)
He manufactured a drift, which was the perfect diameter to mate against the swingarm pivot pin, but small enough to not damage the surrounding area. Even that, and a big hammer – the only result, a bad hand, and a very bad drift. See below pic for the results.
Running out of options, and the customers bill going up due to the time spent, we decided to start cutting. Even that was tricky, as it can only go so deep, so it was a case of drilling, pushing the pin from the other side, and more drilling. Eventually, we had one broken swingarm pin (well, remnants and powder of!) and a very warm drill bit! Not to mention various blisters from the whole job.
We replaced the pin – of course – and all the bearings and seals.
In the end, it was nearer 20 hours of labour – a whopping bill. We did manage to cap it to 12 hours however, but what a long job.
20 hours later, many blisters, skinned knuckles, a broken 1/2 inch drive allen bit, a bent drift – it was mission complete.
All this, because they weren’t greased as per required – so next time your bike is in for a service and the girl or guy behind the counter asks “would you like to have your swingarm bearings, or steering head bearings greased?” you now know what to say. Many customers still insist that they’ll do it next time; its better done now than having to pay over 10 hours in the future!
Most service schedules insist that they are greased every 4 years or so – when did you last grease, or have greased, your bearings?….