Category Archives: Repairs

Left Rear Torsion Bar & Bearing

After the trials of the engine rebuild, see here: and the leaking rear mains seal: it was time to investigate something else.

For years my Aprilia has had a clunk in the left rear suspension. I’d rebuilt the shock absorber but that wasn’t the source of the noise. Next step was to investigate the torsion bar, t in tavola 15.

After I extracted it the first thing I noticed was a couple of wear marks on the inner end.

And putting it between centres in the lathe it had a 0.882″ (2.08 mm) bend.

My first thought was it had been hitting on the inside of the torsion bar guide tube at the differential end, N in the tavola above. I had a perfect spare that I fitted. After a test drive the clunk was still there but I thought maybe there was a little less roll and the rear end stuck to the road a little better.

All that was left to check now was the torsion bar outer bearing, 48056. This is an odd size, 45d x 78D x 18B, and not available from regular bearing suppliers.

I wont go into the details here of removing the left side trailing arm assembly but when it was out on the bench and the bearing extracted the wear in it was obvious. The bearing is located inside the assembly at X, see above Tav 20, and relies on two leather seals, 38-74025, to keep dirt and water out, these had failed and the bearing had pitted and rusted.

Cavalitto is the only source of replacement bearings that I am aware of so one was ordered along with a pair of seals.All is now quiet at the rear. Unfortunately our Covid-19 restrictions are still in place so getting out on the road is not an option right now.


Splish splash, seized water pump.

Just as I was getting near to solving the engine balance issue I discovered my water pump was seized. The pump had been modified in the UK and although they were on the right track the mod had a fatal flaw. An original factory pump uses a series of cork seals but my pump had a modern ceramic seal fitted to the impeller (see pic) with a steel insert fitted into the body to act on the seal. However, they had not taken into account the reverse thrust pushing the impeller back onto the rear PB bush, gradually the impeller was worn down, this allowed water to travel to the front and into the main bearing. I had fitted a sealed bearing there years back but it still seized.

Original pump with seized bearing

Impeller, note worn section and modern seal

Next I order a new one from Cavalitto (€400 plus shipping)

New water pump

When it gets here a trial fit reveals a problem, it’s too long by 5mm, which means the fan belt does not align with the crankshaft pulley. I’m starting to have visions of the radiator horrors from the past (

I contact Enrico, he promises to look into the problem. A few weeks later he ships another that they have modified. It “almost” fits, but still needs another 2mm trimmed to get the the alignment correct.

To cut a long story short I machine the body and the various internal parts to get the desired alignment.

Trim 1mm off the flange

Mill 1mm of the other body half

2mm off end of impeller and matching amount on body

Cavalitto have sold a lot of these pumps so in trying to see why it didn’t fit on my engine/radiator there could be difference in the extension on the front engine mount, I have one spare that is longer, maybe 2nd series are different, I really don’t know the answer.

A look inside the Cavalitto pump shows they have thought the design out thoroughly. The impeller has a collar on the back that works against the rear bush, there is a modern seal that runs in a nylon bush and a sealed bearing. The engine is about to go back into the car so we’ll see how this pump works…



A Question Of Balance.

As the Moody Blues once sang:

And he felt the earth to his spine,
And he asked,
And he saw the tree above him,
And the stars,
And the veins in the leaf,
And the light,
And the balance.

Unfortunately the Aprilia engine isn’t singing with the same lyrical ease as Justin Hayward.

To follow the long and winding road start here:

Tick, tick, tick

Another issue from the Very Long List is the ticking noise from the engine. Since I bought the car in 2006 this noise has always been there. Setting valve clearances and a complete rebuild of the rocker gear didn’t fix the problem.

With all the other engine problems going on I’ve started a complete rebuild, more details to follow in the future! Extracting no.1 piston reveled the source of the ticking noise, a broken piston ring. How long it’s been there I’ve no idea but luckily there was no damage to either the bore or piston.

The engine was rebuilt in the UK back in 1991: (,  and was fitted with AE/Nural pistons, quite different to the originals.



Starter motor

Following up from the “Very Long List” post. First task was take out the engine and gearbox, my favorite pass time!

The problem with the starter motor not engaging correctly quickly showed up when I tested it on the bench. The pinion gear wasn’t engaging fully, see the first video.

What should happen is this:

For those not familiar with the starter motor on an Aprilia it is a Marelli MCE 0.4/6R, mine is six volts, and is activated by pulling a lever under the dashboard then via a cable to another lever on the starter, none of those complicated electronic solenoids to fail, as long as the cable doesn’t break they are super reliable!

A close inspection and comparison with my spare unit reveled the cause of the problem. Someone in the past, not me, had soldered a copper button on to the contact unit and welded an extra bit onto the actuating lever, see the comparison with the spare motor. Simply put this didn’t allow the pinon gear to travel its full length and engage the ring gear correctly or sometimes not at all.

A simple job to remove the extra button, grind off the extra weld and I now have two working starter motors.


A Very Long List –

– of things to do! After the October 2017 ALR Castlemaine & Tasmanian rallies – – were ten-seventy was total rubbish the following is a tentative list of repairs/fixes needed:

1. Engine oil leak.

2. Clutch judder.

3. Rear suspension clunks.

4. Engine “ticking” noise.

5. Engine vibration.

6. Starter motor intermittently not engaging.

7. Left rear wheel hub leaking grease.

8. Gearbox – 2nd gear difficulty selecting down from 3rd.

9. Doors rattling on rough roads.

Some of the above have been addressed already, I’ll post details soon.



Pre Castlemaine 23

October every odd year means it’s time for the Australian Lancia Register’s Castlemaine Rally. This year it is number 23.

Lancia owners around the country are sweating in their garage performing last minute fixes, some small, others almost gargantuan.

This year I tried to avoid the last minute scramble, how organised am I? As mentioned in a previous post I’d overhauled the front brakes but after the last ALR run there was just a bit too much of a whine from the differential.

On the Narrywoolan* website you can read my two previous attempts to fix the problem. This time I entrusted the magic expertise of Mike The Three Wheeler to help me set it up correctly. Taking the whole back end out for the third time was fairly easy. Stripped everything down and got Mike over to help. Sorry I didn’t get any photos of what we did but using some gear marking paste, moving the pinion in and out and shifting the shims on the diff we seemed to get a much better pattern on the gears.

Diff 2015-033

Dropping the rear end. Simple job, remove hand brake cables, top hydraulic brake line on diff, fibre coupling on prop shaft and the four sub-frame bolts!

Diff 2015-058

Diff 2015-101

I took the opportunity to paint everything and clean up the André rear dampers.

Diff 2015-076

André damper with one broken friction disc. Got a new set from the UK, cleaned all the oil and grease off, applied a light smear of SKF LGHP2 grease.

Diff 2015-183

Mike recommended trying some Red Line Shockproof Gear Oil in the diff. Once everything was back in place and a few short runs everything seemed OK. However a longer 200km trip revealed some diff noise at highway speeds and, on return, a more than normal oil leak from the pinion shaft.

Diff 2015-103

The offending leaking pinion shaft.

Diff 2015-109

Even though there is an oil slinger and a modern lip seal it still leaks down the spline end of the shaft. Anyone have a better solution??

After some head scratching and consultation of the factory manual I decided to try some Penrite Gear Oil 140. It’s a mineral oil and the same 140EP spec as the original factory recommendation. Some further long test drives and the diff is now very quiet and the leak is just small. I’ve never been able to come up with a satisfactory solution to stop the leak in the early design of 1070’s diff. Lancia changed the design later in 1937 to incorporate a better system of seals.


Just to annoy me 2nd gear has become difficult to select when changing down from 3rd but it will have to stay that way for the time being. With less than 4 weeks before the rally I’m not going to risk swapping gearboxes as the spare, although all seems to be in excellent shape, has never been run.

From October 16 I’ll be posting a daily blog on the rally.


Front Brakes. New wheel cylinders and linings.

Recent comments about “wooden brakes” and the like from other parties encouraged me to investigate the Aprilia’s braking system. The rear brakes had been re-lined and wheel cylinders refurbished only a couple of years back so my attention turned to the front pair.

The shoes had been re-lined and the wheel cylinders sleeved back in 2008 but an inspection revealed all was not well in there. Both wheel cylinders were leaking and pretty much seized and the linings had virtually no wear, after 8 years something was very wrong.

Leaking cylinders and lining with no wear!

Leaking cylinders and linings with very little wear after 8 years!

Old wheel cylinder

On to the Cavalitto website to see what parts they had for brakes:
Two new front wheel cylinders and a set of brake linings were despatched via UPS

New parts

New linings and new alloy wheel cylinders

The shoes went of to BGT to get re-lined. Here I was advised not to use the supplied rivets but to bond the new linings. I don’t know why but they always coat the nice alloy shoes with some yellow/brown gunk that won’t come off, I guess no one sees them but I far and away prefer the clean alloy look.

New Cavalitto linings bonded to shoes

New Cavalitto linings bonded to shoes

The new cylinders were bigger than the old Lockheed originals, about 10mm longer and the piston 3mm greater diameter but I was assured by BGT they would be fine, just give a ‘higher pedal’

Top; new wheel cylinder, bottom old Lockhead cylinder

Top; new wheel cylinder, bottom old Lockheed cylinder

Old Lockheed cylinder

Old Lockheed cylinder

New Cavalitto wheel cylinder

New Cavalitto wheel cylinder


New wheel cylinder and re-lined shoes

New wheel cylinder and re-lined shoes

After fitting the new cylinders and shoes, bleeding the system using the one person bleed method and adjusting the shoes the first test drive revealed all was not well; the brakes were not releasing correctly and partially locking on! After much head scratching, more bleeding and adjusting the problem didn’t go away. An email was fired off to Cavalitto with the reply to make sure everything was cleaned with alcohol and the workshop manager would get back to me after the weekend. Advice from Puce Goose & Stainless Stephen thought muck in the master cylinder would definitely be the problem, what do they know?? I thought maybe the flexible brake lines were blocked or collapsed. In a moment of rational thought I phoned Mike the Three Wheeler, automotive engineer extraordinaire who lives not that far away. He was going to be driving past the next day and could stop for a look. Mike’s diagnosis was the master cylinder residual pressure check valve didn’t need to be there with the new wheel cylinder piston seals.

New wheel cylinder with modern seals

New wheel cylinder with modern seals

Removed the master cylinder from the car, always a fun job with not much room, stripped it down, found the inside to be spotless, and removed the inner rubber from the check valve.

Master cylinder hidding underneath the car

Master cylinder hiding underneath the car

Rubber valve removed from residual pressure relief valve

Rubber valve removed from residual pressure relief valve

Reassembled the lot, bleed the system again and adjusted the shoes. This time the brakes didn’t seize and stopped extremely well. A nice progressive pedal with room to heel and toe, and pulled up in a nice straight line. Once the linings are bedded in they will only improve, but right now its are the best they have ever been. A reply from Cavalitto on the Monday said new return springs for the shoes would have helped and probably worked, but doing what Mike suggested was also ok.


Instrument Switches

When I got 1070 the instruments switches were not the originals, I believe they were amongst the items lost during the UK restoration when the first company went bankrupt, so they had substituted these.

Non original switches with my labels!

Non original switches. The labels were to help Ben when he drove the car in 2013!

Earlier this year another Aprilia owner kindly donated two of the push button ones and a back panel they are all fixed to. Then, inspired by Andrew’s comment that my trafficator switch was fitted upside down and ergonomically inferior, I asked our friends at Cavalitto if the had any of the top type. They do, a nice modern reproduction.

Instrument switches-002

Bottom push button switch

Switches from cavalitto

Reproduction switches from Cavalitto.

Now the wiring under the dashboard is not exactly in the neatest condition. With extra wires for two flasher cans, a buzzer circuit for the indicators, some extra earth connections and a high beam relay not helping. The ideal solution would be to pull the dashboard off and sort it out, but I have a friend dropping by later in the week and every time he’s been the Aprilia was in bits and he’d never had the chance of a drive, so the for the time being I just fitted the new switches.

Instrument switches-008

It’s actually worse than it looks…

I rearranged them in close to the original positions, well sort of! Power to my fuel gauge is hard wired, it should go through a push and hold switch (1) and the high beam is switched via the top right switch (6), should be on the headlamp switch circuit with the ignition key(4), see the drawing for the correct locations and the following photo for my layout.

Page -011

New switches. Top left wipers, top right high beam, bottom left dash lights, bottom right interior lights

New switches. Top left wipers, top right high beam, bottom left dash lights, bottom right interior lights

So despite the wiring mess they worked and look much better than the others. Next project is to replace the front wheel cylinders and re-line the front brake shoes.


Petrol tank clean and repair

Back in the early ’90s when the car was restored in the UK the petrol tank had been lined with ‘Slosh’ tank liner. Recently I’d observed the liner was starting to bubble and leave a large amount of deposits in the fuel filter.

Petrol tank-001

Lifting and bubbling old ‘Slosh’

Petrol tank-002

Muck in the filter

Because of the internal baffles the only way to clean it out was to open it up. The tank is a clam shell design with a soldered seem around the middle. I took it to a local radiator repair shop. With an oxy torch the solder was removed and the tank opened. WARNING: Don’t try this yourself, a naked flame around a petrol tank should always be left to the experts.

Petrol tank-006 Petrol tank-007

Once opened the next task was to remove the old liner. Some of it peeled off in big chunks but for the rest I bought a fuel tank renewal kit from RustBuster. With this you get their ‘Aircraft Stripper’, basically a normal paint stripper, rust inhibiting degreaser and a can of new formula ‘Slosh’ (suposedly resistant to ethanol fuels). Below is the result after stripping the liner off. Luckily the tank looked in good condition with only very minor surface rust.

Petrol tank-008 Petrol tank-009

A day with the electric drill and grinder and all the old ‘Slosh’ was removed. The exterior paint was also stripped. There was some damage to the bottom section of the tank that had been filled. I took it all to Marc Bondini, Lancia expert and restorer, to have the dent fixed and the two halves soldered back together.

Petrol tank-011 Petrol tank-012

Next was to re-line the interior. After a clean out  with the supplied degreaser the new ‘Slosh’ liner was poured inside, carefully following the instructions to rotate the tank to ensure all the internal surfaces were coated before draining the waste out and leaving it for 4 days to fully cure. Next four coats of POR15 paint was applied by brush to the exterior and left for a further four days so everything could cure nicely.

Petrol tank-013

FIRA makers stamp. As Paolo kindly pointed out, Fabbrica Italiana Radiatori per Automobili. The same Lancia owned company made the Aprilias radiator.

Petrol tank-014

Painted and ready to go back in

Back in the ’90s when the tank had been installed after the restoration they found the fuel outlet had been clogged, so a quick solution was adapt the fuel outlet to the breather on top of the tank and a blank filled the correct outlet. To put it back to the correct setup the internal pickup tube cleared, the wire mesh filter on the drain plug cleaned of slosh, took about four soakings in paint stripper to get it clear, a new breather pipe was made and finally a new copper fuel line was bent up. Finding 8mm copper tube proved quite difficult, I had enough to do the breather but not enough to finish off the outlet, I only needed about 40cm. None of my local plumbing suppliers had any, but could get me some, however the minimum order was for 40 metres! So a quick search on the net found some with RS Components which they managed to deliver the next day, amazing.

Petrol tank-003

totally clogged drain plug filter

Petrol tank-004

Petrol tank-016

New breather tube

Petrol tank-015

Back in and looking good.

Once the tank was reinstalled  30 litres of petrol was added, the tank sender unit (a work of art in itself) was re calibrated , a quick check for leaks, none!, and we’re back on the road.