Swingarm, drivebox and shiny shocks – 21 Jun 2014.

Back so soon!

My next job was to fit the universal joint in the bearing in the swingarm.

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Guzzi UJs are expensive. I was surprised to find that this one was still in good serviceable condition. Although the movement of all its bearings are very “free”, there is no sign of any shake in them. The fit of the UJ in its support bearing is still good. They can spin in the bearing which then accelerates wear and makes the UJ vibrate and so then wear its joints. To try and keep things as they are, I froze the joint in the freezer then coated the mating surface with Loctite 641 bearing retainer and whacked it into place.

To get the UJ and swingarm into place you have to first remove the bolts holding the footrest carriers and frame sections together. I fitted the rubber boot onto the back of the gearbox without its clips and folded it back on itself. I put some grease onto the exposed splines of the gearbox and then it’s a case of making sure the spacers are in the swingarm seals on top of the bearings and offering it up. At the same time you have to fiddle the end of the UJ onto the output shaft of the gearbox. As soon as it was on I shoved the swing arm pivots in.

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You have to be careful with these as they are a nice fine thread and if you cross them it’s possible to damage the thread in the frame and I’ve certainly not got a tap that size. I’ve bought new pivots with an Allen key hole in. This is a much better idea than the mangled screwdriver slot in the originals. The pivots have to go through the middle of the spacers. I like to get them both started then screw one right in as far as it will go, back it out part way and do the same with the other one to make sure everything is seated. The swingarm then needs to be centred in the frame. I take up the slack in the bearings trying to keep the same amount of pivot sticking out of each side. Then I use my caliper to measure each side and screw one out and the other in by the same amount until they are even.

Next I put on the left hand shock to support the swing arm. Before I could do this I had to sand down the powdercoat on the top mount. In this photo I’ve also fitted the locknuts on the pivot bolts.

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Next the frame connecting bolts and footrest carriers needed to go back on. On the left hand side the rearmost nut has no clearance to the swing arm on full drop unless you mis-align it (and this is with the correct length shocks). It only just touches.

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It’s the same on the S3 which has had a half nut fitted here but I’m not keen on that arrangement as it leaves threads exposed to the dirt. So, I decided to bevel one face of the nut and this gave the necessary clearance.

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I then turned my attention to fitting the Jubilee clips that secure the rubber boot over the UJ to gearbox joint. This is easy as the clips are large and can be disconnected, fed round the boot then refastened. You don’t need to do them up so tight that they cut the rubber.

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The drive box was rebuilt some years back. I remember I drained the oil from the box during routine maintenance and it came out silver! When I went inside, I found that the pinion didn’t have one of its teeth intact. It had “vibrated a bit” but I was lucky a tooth hadn’t jammed the lot solid as I tanked down the M4. Rebuilding these is not for the faint-hearted and requires accuracy and patience.

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Here are the drive shaft parts and box with its gasket. You can see that the pinion housing has been kept in place during storage using the mounting nuts plus a couple of big nuts used as spacers. I use dome nuts on these studs as they are very exposed to road dirt.

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I greased all the splines and pushed everything together, securing the drive box loosely with the dome nuts. Before tightening these you should fit the rear wheel and its spindle to ensure everything is lined up properly. I just fitted the spindle, as the other parts aren’t ready yet, then wound the nuts up tight and it’s all ready for the remaining shock absorber.

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So this is where I’m up to now.

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I was very lucky to get hold of a pair of the correct Koni shocks as fitted to the bike when it was new. The originals are in a box somewhere showing wear to the shafts and with very rusty springs. I had previously fitted Koni dial-a-rides but these are now on the S3. Last year I got these from Robert Haag/Konimon in the States. He specialises in rebuilding Koni shocks and found a pair of new old stock dampers which he then cleaned out and rebuilt as some of the rubber internal parts can deteriorate. I’ve got the original box and fitting instructions and the dampers even have their transfers on still. He mounted a very good secondhand pair of original springs to the dampers and I bought them for about the price of a new set of Ikons.

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I’ll have to turn this spring to hide the wear . That’s all the damage there is as there’s none on the other spring.

 

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