Series I vs. Series II front axles

[davidwheeler]

I am in correspondance with David Hill who has problems with wear in his 2nd series front suspension.   I have 1st series parts spare but they are substantially bigger than his.  Is the 2nd series really more slender than the 1st or has he an Ardea axle on there?

[Raahauge]

The bottom bush on our 2nd series car appears to have a nominal diameter of 40mm. I had the top badly worn bushes cleaned up and new sleeves made and they are now 42mm, they must therefore have been less than that when new but I doubt they were 40mm, maybe 41mm.
I have some parts off another axle on which the bottom bush dimensions are the same but the detail construction of both top and bottom bushes are  different.
The bottom bushes are interchangeable but the top not so.
I believe the Ardea has a narrower track and smaller drums.
Mike

[davidwheeler]

Interesting...   My bottom is 40 and the top 42 also.  David's, however, are 29 lower and 35 upper.

[simonandjuliet]

Can't comment on this just yet because I am due to take my S2 axle apart (very last type) soon. But in order to do it without damage I have had this tool made by a friend

[DavidHill]

Evening all,

find attached pictures of my sliding pillar bottom section. my Aprilia is a 1948 model, but am not sure whether the axle is original to the car. is this a 2nd series or 1st series part??

[Raahauge]

The bottom sections on our late car is the same as Simon's but those on the spare axle is like David's.
I think most of my spares are first series so I had supposed that the axle was too but maybe not.
A benefit of the later type is that when the lower blanking piece with the two drain plugs is removed the outer bearing is a no longer a blind hole and can therefore easily be ground/honed for renovation.

[simonandjuliet]

A little more on front axles .....

There are at least 3 types (maybe 4) and I think that the chassis range is as follows

early S1 (no picture yet) : until 238-3000
later S1 : from 238-3001
early S2 : not sure exact number yet, but largely similar to later S1, but different part numbers, up to 438-13713
Late S2 : From 438-13714 'til end

These figures taken from the parts books, but I will find other sources as and when I find them

[williamcorke]

My S1, 38-1427 has front suspension that is unlike other S1s I've seen, including my spare front axle. Omicron thought there were parts missing from it when I sent a photo, but whether or not that's the case, the top (damper) section is a different shape (much less tall) that the usual S1 in the second photo (with thanks to http://narrywoolan.com.au/ and his excellent Aprilia website).

[DavidHill]

3 or 4 different designs on one model in 10 years! Classic Lancia engineering.  I wonder what drove the redesigns? they all look equally complex and expensive to produce, so it does not seem to have been to reduce costs/or production time.  If they had wanted to change the handling then they could have simply changed the spring (within the same dimensions) or the damper valving...so that doesn't make sense either.  It would make an interesting Engineering degree project to compare the designs on a suspension test rig and for production costs and wear resistance etc.

[davidwheeler]

My S1, 38-1427 has front suspension that is unlike other S1s I've seen, including my spare front axle. Omicron thought there were parts missing from it when I sent a photo, but whether or not that's the case, the top (damper) section is a different shape (much less tall) that the usual S1 in the second photo (with thanks to http://narrywoolan.com.au/ and his excellent Aprilia website).

I think you are missing the spring shrouds.

[Andrew Cox]

I think there is a bit more missing than the spring shrouds. Noel Macwhirter and I spent a few minutes peering under his earlyS1 car this morning and comparing it with the picture provided. Without further info we are guessing that the pictured front end has been somehow converted to incorporate modern hydraulic shockers. With regards to David Hill’s comments about the four variants of the Aprilia front end, I suspect ( and Geoff Goldberg’s research bears this out) that the damping of the first three variants was considered inadequate by Lancia and the cause of some customer complaint. The last variant  ( designed by Francesco De Virgilio) fixed the perceived problem and became the model for the Aurelia.

[simonandjuliet]

Indeed ,the final incarnation is very similar to the Appia

[DavidHill]

hmm, so can anyone confirm whether the Series 2 front suspension provides a better ride / handling than a Series 1 front suspension?  Or was this Lancia being very picky with how the Aprilia behaved - ie Vincenzo said "not to change anything" after his first drive of one

[GG]

I believe there were problems with the upper valving - that upon too much driving, the oil would get too hot possibly, and misbehave. De Virgilio's studies look closely at the upper adjustment, and also oil temperatures from extended use. The problem was such that there was a need for the s.1 cars to frequent Lancia's service shop in Torino. They were quite relieved with the fix.

What was odd was trying to unravel when the fix was implemented. De Virgilio always told of fixing the Aprilia, but we found the fix implemented first (if I recall correctly) in the Aprilia Militare (during the war) and the Ardea, before showing up in passenger Aprilias. If interested, maybe take a look at his sketches in the "big book", shown below. 

[davidwheeler]

I have to say my 1938 car seems fine so long as I keep the front suspension topped up  with 10/40 oil!