Narrywoolan*

Front Suspension 2008/2011 - 2012

While I had the engine and gearbox out and was waiting for the infamous radiator repairs to be done I took the opportunity to have a look at the front suspension units. They were making a fair bit of noise when the steering was turning, plus I was curious to see how these things worked.


2012. The car had developed a clunk in the front left suspension and grabbing the wheel you there was a lot of lateral movement. So time to strip the suspension down to see what the problem was. The top bush 38-73049 was badly worn, +50 thou in an oval fashion. New parts aren’t available so new ones had to be made. They needed to be case hardened and precision ground to .004” - .006” clearance - see below.

1st series manuals can be found here: 📗

There are four variations of Aprilia front suspension, this is the early 1st.
There are four variations of Aprilia front suspension, this is the early 1st.
If you look at the changes section you’ll see when the updates happen.
If you look at the changes section you’ll see when the updates happen.
As fitted just after the car arrived from the UK.
As fitted just after the car arrived from the UK.
My collection of home made tools.
My collection of home made tools.
Starting point
Starting point
Note the grease nipple for the bottom spring section, this should be an oil filler.
Note the grease nipple for the bottom spring section, this should be an oil filler.
Lower spring and parts.
Lower spring and parts.
p/n 48703.The thrust bearings had been running dry and were stuffed. New set from Cavalitto.
p/n 48703.The thrust bearings had been running dry and were stuffed. New set from Cavalitto.
Starting at the top.
Starting at the top.
Rebound springs. Very important to reassemble in the same order.
Rebound springs. Very important to reassemble in the same order.
Withdrawing internals.
Withdrawing internals.
Top parts.
Top parts.
Complete suspension unit. The only problems were the thrust bearings and the hard chrome on one base plug.
Complete suspension unit. The only problems were the thrust bearings and the hard chrome on one base plug.
38-604, 38-73052. Make sure the little flap valve is there and working
38-604, 38-73052. Make sure the little flap valve is there and working
All painted and ready to be reassembled.
All painted and ready to be reassembled.
New brake linings and overhauled wheel cylinders, done by BGT.
New brake linings and overhauled wheel cylinders, done by BGT.
Ready to go.
Ready to go.
New oil nipple. Make sure they both face to the front, or they will get damaged when turning.
New oil nipple. Make sure they both face to the front, or they will get damaged when turning.
Oil syringe. I use a mono grade 30W engine oil for the top and any heavy 50 weight oil for the bottom section.
Oil syringe. I use a mono grade 30W engine oil for the top and any heavy 50 weight oil for the bottom section.
By 2011 I had a persistent leak from the bottom of the front right suspension. Spotted this “crack”
By 2011 I had a persistent leak from the bottom of the front right suspension. Spotted this “crack”
The centre section is held in place with a wire clip then soft soldered at manufacture. In the end an easy fix.
The centre section is held in place with a wire clip then soft soldered at manufacture. In the end an easy fix.
2012. Front left hand suspension.
2012. Front left hand suspension.
The top bush had worn +50 thou oval.
The top bush had worn +50 thou oval.
Top sleeve showing the wear on top bush, new bearing collar inside.
Top sleeve showing the wear on top bush, new bearing collar inside.
L - R. Bearing Collar 38-73070, Top Bush 38-73049, Top Sleeve 38-73041
L - R. Bearing Collar 38-73070, Top Bush 38-73049, Top Sleeve 38-73041
TAV 25
TAV 25
TAV 24
TAV 24
The top bush can be tapped out with a brass drift.
The top bush can be tapped out with a brass drift.
New parts. My local engineering co. made them ($350!) Had to be case hardened and precision ground.
New parts. My local engineering co. made them ($350!) Had to be case hardened and precision ground.
Time will tell how the new part performs.
Time will tell how the new part performs.

2012 update

Special Announcement

From early July 2022 this website will close forever. If you wish to download anything from here do it now.

In the future you can contact me at macwhirter@iinet.net.au

Thanks for all your kind coments and advice over the past 12 years.

Noel Macwhirter