All shimmed up

The end-plate is removed again ready for trying a 1.7mm shim. I use M6 allen bolts for this but other states have the proper T-Bar extractors in their toolkits (we don't have a full toolkit in the ACT, having only a few local members...). I'm an expert at this now! The best technique is to just start the plate moving with the extractors/bolts and then give it a sharp tap with a mallet on the thick lumpy bit next to the cluster bearing (marked with a blue arrow). Repeat until you can wobble it off. This tapping stops it going wonky - should have reread how to do it the other day...

Before doing the final shimming I check to see that the layshaft is still tight through the bearing. Yep, all good.

Back on with a 1.7mm shim, but it's too small when checked with a feeler gauge. Looking at the AF instructions and they recommend going up sizes until a shim locks the gearbox, and then going back one size, rather than trying to get an accurate measurement with a feeler gauge. The gearbox locks for me with a 1.9mm shim. Checking with a feeler gauge and a 1.8mm shim gives 4 thou clearance - looking good, and in line with the mental arithmetic I did before! Note, the max clearance in the instructions for the AF 5 speed is 5 thou. Much less than the 11 thou recommended for a standard box!

Now I'm happy with the shim size it's time to check that the rest of the box works. Paul Cain had recommended not fitting the cluster until after shimming because this makes it easier to take the end-plate on and off. Everything comes out again, I lube and fit the cluster bearing, and am chuffed to read in the AF instructions that the shim should not be fitted. There's obviously no room with a 5 speed cluster, but there is also a school of thought that the shim just stops oil getting to the bearing. I'd been in two  minds whether to fit it, but problem solved.

Cluster in and refit the loose gears...all looking good.

The final check is to fit the clutch spider, torque it up to 50 foot lbs, and see that all the gears mesh and work. Yep, they do.

The last job for today is to fit the selector rod and bracket, using allen bolts to give more clearance, as suggested by Mark. Fifth is sweet. First is clear, just. All will be good until we get some more wear in the linkages...

Well that was a productive session. Building a 5 speed is much more involved than a standard box, and of course I have to remove the end-plate one last time, to replace the studs I damaged at the end of Part 2. Hopefully Steve Diffey has some in stock.

<Next> <Previous>

If a job's worth doing, it's worth doing three times.

Having had a couple of night's sleep, and an Australia Day run on the Jet for pizza with the Canberra Swarm, it's time to think about the previous build. I'm obviously going to have to use some of the supplied extra shims. With the selector in first touching on the end-plate the layshaft needs to move back. A shim in front of the bearing will sort this...

Equally, I'd noticed that the layshaft bearing track wasn't 100% flush with the end-plate, so the first job was to remove it again, put it in the freezer, heat the end-plate and refit (I'd just hit it in at room temperature before). Anyway, result, it's now absolutely tight in.

My brain had wandered over what I'd down before, and I'd pondered on why the selector fork would have been hard against the dog? Then I remembered that I'd already "adjusted" it, while inspecting parts against the recommendations in Sticky's manual. Basically the recommendation was that you should be able to fit a 5mm drill bit through the holes and the gap between the legs should be approximately 64mm. This I'd done, but then we'd bent the top leg out again so that it cleared the dog...I'm now thinking that the top pawl may be sitting too high. Reading back though the AF instructions and they recommend moving the selector shims in order to adjust it's position, rather than bending one arm. Out comes the arm again, and sure enough the legs are out of line and over 65mm apart! So, fixed again...

Refitting the selector and following the AF instructions, I now use both shims above the O-ring, which gives a smooth movement and keeps the 64mm gap between the arms. This I recon optimises the contact area between the pawls and the sliding dog. Will this matter at the end of the day? Buggered if I know... 

Hmm, before I remove the hub bearing and put a shim behind it I should check that the loose gears align okay, just in case something drastic is required. Yep, they're pretty bloody good.

Onwards. Heating the casings and tapping on the layshaft brings the whole lot out in one. I'd decided to do this because the layshaft had been so tight in the bearing, so why remove it unless I have to...

The picture shows the shim. I opted to use the larger 0.5mm shim in front of the bearing because it seemed like I needed to move the layshaft a decent amount.

For refitting I froze the bearing and layshaft, and heated the casings. Yeah, Nicky is a proper scooter girl and doesn't bat an eyelid at bearings in the freezer (or casings in the oven).

Once the bearing and layshaft are back in all 5 gears are checked again. First now clears lovely, WAHOO!, but fifth has the selector hard up against the casings and no clearance between the dog and hub bearing, ARSE!

What now? File the offending selector arm, remove the layshaft again and refit using the smaller 0.2mm shim this time...

Third time lucky! The shaft is back in, after another round of heating and freezing. A feeler gauge proves there is a gap between the selector arm and the casings, and between the sliding dog and rear hub bearing. In first there is a clear gap to the end-plate. All is looking good. Next the loose gears are checked, and they all align perfectly!

If everything can shim up then we're home (probably). The smallest shim I have is 1.4mm, so let's use this and see how it looks. The end-plate is bolted down (using the 4 good studs - yes, yes, I know I buggered the other two...). Measuring the gap I can get a 20 thou feeler gauge in. Some head-scratching and mental arithmetic later and I figure a 1.7mm or 1.8mm shim will result in a perfectly shimmed gearbox, within the AF recommended limits of 1.4mm to 2.0mm. Well, that's the theory (why are we using thous and metric? Thank god the gauges have both written on them!)

Anyway, it's definitely time to leave the proof to another day. We've run out of beer so it has to be gin and tonic before packing the tools away. Hard life.

<Next> <Previous>

One thing at a time and two hands make light work!

Fellow scooters nuts and old friends Fleur and Mark were visiting Canberra. Mark, being at a loose end while Fleur worked, came around to lend a hand, which led to a productive day.

First up, checking the studs fitted yesterday. Sticky's manual recommends a minimum thread depth of 20mm and they all were over - result! Note, the longer and different coloured stud, which is fitted where the exhaust tail-pipe clamp gets bolted.

I'd checked and changed the engine mounts earlier. All club toolkits have silent block removal/replacement tools. Early purchases were these cheap versions. This one needed the chrome plating removing from the inside before it would work. We also had to replace the centre bolt after it had been used a few times. More expensive Casa Lambretta ones, supplied by Rimini Lambretta Centre, have now been included in many club toolkits. To use simply follow the instructions in Sticky's manual.

Now the fun begins. It's time to fit the rear hub bearing. I left Mark heating the casings while I went inside and put the new bearing in the freezer. AF recommend using a new double bearing, but this puts the rear wheel slightly out of line (or so some say). I went with a standard RIV Italian bearing, as supplied and recommended by Steve Diffey. After ten minutes in the freezer, this was packed with grease, the outside edges cleaned with parts cleaner and it went straight in to the heated casings with no force required. Note, Steve has since questioned why pack with grease, and I agree. This was in Sticky's manual, but using gearbox oil makes more sense. After all this is what it will run in.

To be 100% sure it was seated right I checked it with a bearing puller. Yep, she's home!

The next job was to fit the oil seal studs. Once again these were double-nutted in to place with a dab of Loctite Stud Lock.

Then it was time to fit the oil seal. This wasn't too tricky, just needed the inner edge easing in to the bearing with a finger nail and tapping fully home with an oil seal drift. I've got one for fitting mag housing seals that was a good size to use.

Now it's time to fit the oil seal spacer and flange. Flange. Love that word! Anyway, it's absolutely vital that the nuts are not overtightened, and the ABSOLUTE max torque setting to use is 4 foot-pounds, otherwise the flange will warp and the studs will bend. This has been the case on practically every Lambretta engine I've stripped. Due to the low torque setting, and the use of flat washers, I used Loctite on the threads and M6 Nyloc nuts (belt and braces). Well, I would have done, but I only had two! I've since been given more (thanks Nico at Motorini) and will use them for all four before the hub goes on, honest!

Now the AF 5 speed gets unpacked and the much head scratching over the instructions ensues! Do I need to fit a shim on the layshaft before it goes in the bearing? Quick phone Paul Cain! He's busy but phones back, by which time we've worked out that you need to build the box once without any of the extra shims, then measure up and use them if needed! Paul confirms this is the case explaining all the slight differences between what should be standard sized layshafts and bearings! I'm now beginning to understand why all the 5-speed suppliers recommend that only competent mechanics fit them.

I wasn't 100% happy with the condition of the splines on the Indian layshaft when I stripped the motor. It would probably be fine, but with fitting a 5-speed box, new hub and tuned motor, I'd decided to order a new one from Steve Diffey. He supplied a FA Italia one, which are excellent apparently. The sliding dog from the five speed was then fitted to this. This involves juggling springs and balls, and bionic fingers. Needless to say we didn't only do it once!

The AF kit instructions show some end-plate checks that I hadn't seen in Sticky's book, so these were carried out next. Basically the check is to see that the 6004 bearing face and the machined surface where the gear shim runs are parallel. Mine was good!

The kit came supplied with new gear selector pawls and circlips, so these were fitted next. Finger nails only required. I can never finger out how to use pliers on these tiny circlips!

Once fitted the pawls appeared to work perfectly in the sliding dog. Yeah, things are going too well! Note the new O ring that has also been fitted to the layshaft.

The selector fork has to be fitted in to the casings next. A new O ring is retrieved from the pack supplied by Steve, but then we realise that we have to drop the engine from the stand. The frame of the stand blocks us from inserting the selector rod. Only a minor annoyance but the first thing that hasn't gone like clockwork today. Following Sticky's instructions I'd centre-punched the rod and fork before removing, in theory meaning they can be put back in exactly the same position. Well it took some looking but we eventually found the punch mark...Also following Sticky's advice, and where an extra pair of hands was really useful, we made sure that the selector was bolted in place with no up and down movement, giving the tightest possible seal to prevent gear oil leaking.

The new layshaft was a really tight fit in the bearing. Light tapping was not going to help, and I wasn't going to use any other sort of tapping on a bearing!

I'd bought one of the MB Scooters layshaft pulling tools, but the shaft wasn't through enough for the puller's nut to fit on the thread! A bit of head scratching and I came up with the idea of using the hub cone in place of the much longer sleeve from the tool. This worked, but only thanks to Mark being able to grip a cloth bound layshaft enough to stop it spinning while the nut was tightened! This got it in far enough to use the tool, which includes a captured bolt that sits in one of the splines to stop the shaft spinning. It still took two even with the tool, one to hold a spanner on the sleeve and one to use a wrench to wind the nut!

Finally the shaft was fully home, however it wasn't spinning freely! Closer inspection showed that the top leg of the selector fork was pressed hard against the sliding dog. Sticky does mention this and shows someone bending the arm with a screwdriver between it and the dog. It give this a quick go, but, well, it looked like it'd just bugger the bearing. My plan was to remove the whole selector and bend the leg in a vice, but Mark suggested using a ring spanner over the arm to do it still in place. This worked a treat, and after three "adjustments" the layshaft spins smoothly and the selector slides lovely!

The next step in the AF instructions is to check the neutral position of the selector arm. Well bugger me if the arm isn't about 130 degrees out! Looks like we hadn't found the correct centre punch mark when fitting. The whole selector arm has to come out, the sliding dog needs removing, meaning the springs and balls need refitting...At this point photo taking was forgotten as we; removed the selector, found the correct punch mark, fitted the selector again, and somehow managed to refit the dog, springs and balls with the layshaft still in place. This last bit needed several attempts, a tap from the trademark Lambretta persuading mallet and a trip inside for a Bandaid… Finally the arm was in nearly the position shown in the AF instructions.

All five gears positions were selectable, but, to be sure, I fitted the tie-rod and gear arm brackets, using a trunnion to connect it all up. I wanted to make sure that nothing would stop all five gears being selected with all the gobbins in place! Sure enough there was one arm position where fifth seemed a bit dodgy, and one where first seemed a bit close. We spent a while unbolting the selector arm, carefully moving it one notch on the spline. Is that better or worse? We also tried some brand new Scootopia controls in place of the original Indian ones, which for whatever reason I had laying around. In the end we both agreed on the original position, the other one looking like an impossible angle for the cables to move the arm from fifth. Selecting first still moved the arm very close to the front bolt on the bracket, but Mark suggested that using an allen bolt in place of the hex head would give more clearance, and I was happy with that. Whatever happens I don't want to have to strip the whole engine down again due a problem found when cabling up! Worst case an after market set of controls might be required.

Moving on and it was time to replace the 6004 bearing and layshaft bearing track in the endplate. The old 6004 bearing was whacked out. I'd bought the proper drift for fitting the new one, in anticipation of this job, and fitting was quick and simple. Money well spent...

Steve had supplied a sealed bearing, so I rang him to see if I should remove the seals. While discussing this he mentioned a potential problem with the selector fork hitting the back of the engine casing, preventing fifth being fully selected, even though it looks like it's working. All good until riding for the first time when it jumps out of fifth! Checking this and I'm definitely fully selecting fifth with clearance between the selector arm and casings after the positive click in to fifth gear position. Phew. Still it's so good to be able to phone the dealers here in Oz and get this sort of advice on the spot. Both Paul and Steve have been phoned today, and both provided excellent hints and tips. I know the other superdealers will also do the same.

Next, change the layshaft bearing track. The 6004 drift worked great for this job as well.

At this point Mark was phoned by Fleur. Finally she's finished work and they can start the long drive back to Sydney. Thanks Mark. I made amazing progress today thanks to your help and suggestions! Two heads were definitely needed at times.

The AF instructions suggest fitting the layshaft bearing and end-plate at this point, to see that the layshaft still spins freely. So I do this and it does, which is nice.

Unfortunately it looks like first is no longer fully selected, the selector dog possibly touching the plate! Now I decide to call it a day, and have a beer before putting my tools away. I really should have done that, but halfway through the beer I decide to remove the end-plate and then stop. Oh dear, somehow the plate goes wonky while being removed and the threads on one of the new studs get porked in the process. 

Like that last run on the snowboard, that last round of schnapps, that last fandango, just don't do it!

​YOU ALWAYS FUCK UP THAT ONE LAST LITTLE THING...

This is the first part of an occasional series where I actually get my finger out and rebuild an Indian GP engine, taking the opportunity to use some of the club tools and plug bits from various super dealers.

As some of you will know I bought an Indian restored GP from AF Rayspeed six years ago. The "restoration" was basically a complete new build around the original 1977 frame, using all new Indian parts. Anyway, after 8000 mostly trouble free, and it has to be said often full-bore long distance kilometres, I pulled the engine apart in the knowledge that this was considered the usual "life" of an Indian built engine. Sure enough the crank, gearbox and various other bits and bobs were consigned to the bin!

The plan is to rebuild around a second-hand TS1 top-end and brand spanky new 5-speed AF gearbox, which was supplied by Paul Cain, the Australian AF Importer. Most other bits and bobs have been sourced from Steve Diffey of Lambretta Obsessions. Guidance gratefully provided by Sticky's Green Manual, which he and Stuart Lanning supplied to the club at a considerable discount, as those members lucky enough to get one will know.

So where to begin? Well I thought about following the manual page=by-page, but as I'd listed and bought new bits while I pulled the engine apart, all of which are now in various boxes around the garage with me only half-remembering what I have, I decided to work my way through the boxes and fit bits as they came to hand, in a hopefully fairly logical order (what can possibly go wrong?)

Step One - Replace the Gear Cluster Bearing Track.

Sticky talks about the Indians fitting the track proud (p116), and sure enough this was a problem with mine. Hence the cluster was pitted, overheated and generally buggered from a lack of lubrication, which did let me justify forking out for a bargain AF 5-speed box! Much better value than other 5-speed boxes and supplied with the new improved whatsit and all shims, shams and doodaas by a very professional Paul Cain.

Anyway, Sticky's manual makes removing the old track sound a bit daunting, but it turned out to be a doddle, using an old 5/8ths socket that had the required 22mm diameter, heat, grease and hydraulic pressure (heat, pack with grease and whack socket in to the middle of the bearing). With a single repack the track popped out like magic!

I wasn't happy with my first attempt to fit the new track. It still sat proud. So out it came again and after checking the casings for burring, I popped the track in the freezer for ten while heating the casings. This time a couple of taps with a bearing drift had it nicely in place

What next? Well the casings needed a final clean. Everyone probably has their own ways. I use Kero and old toothbrushes to remove the worst of the crap, then finish off with Supercheap parts cleaner. I also find white spirit is good for removing those last stubborn bits of old gasket. This picture shows the first of the utilised club tools clearly; the engine holding tool, which if my memory serves me right, was supplied by Chris Townsend.

The engine internals parts box throws up a new set of crank-casing studs, the Indian motor being fitted with bolts originally. Now those who fitted these because "that's what the racers did" back in the eighties will know what a recipe they are for stripped threads!

Fitting was a simple job of double-nutting. Sticky suggests using Loctite Stud Lock when fitting, but I've struggled to remove some in the past. I compromised by using a tiny amount of it.

The next things that could be fitted that came to hand were a new set of end-plate studs. I thought the ones I had looked okay, but Sticky said that some dealers recommend always changing them. I had them so why not? Sure enough some of the old ones came out far too easily! I happily fitted the new ones with stud-lock and refitted the dowels using Loctite Bearing Fit, as suggested.

Well that's it for part one. Not the most exciting start! Hopefully it contains some useful tips, and/or, you can let me know if I've stuffed anything up!

Cheers,

Chris.