Hello,
I have a 1972 Fulvia 1.3S. I am looking to replace the front shocks and the buffers that sit between the transverse leaf spring and upper control arms. The car sits a little low in the front, and the current buffers measure 61mm (front wheels off the ground). I would like a lift of 10-15mm. The available sizes are 90 and 70mm. Would anyone who has installed these happen to know how much a new one will compress when installed?
What I would like to avoid is installing a new 70mm, only to have the car back to where it is now if it compresses 8-9mm, and conversely I think a 30mm lift will look ungainly if I decide to go with the taller one and there is no compression.
I'd appreciate any insights. Thanks.
S2 front suspension buffers
Re: S2 front suspension buffers
Rubber (and springs including leaf springs) can be used elastically or plastically. If used within the elasticity limit it will return to its original form. Plastically is if the elasticity limit is exceeded. The rubber will be deformed permanently.
Those rubbers have always been an enigma for me.
Good quality natural rubber with the density and diameter of the buffers used by Lancia cannot work elastically. The limit is exceeded. So they deform permanently as you have noted.
Also the rubber has to be flexible and remain flexible. The length of half the transverse spring is much different form the length of the upper wishbone. The angle between the two varies when moving up and down. That requires a buffer which can still bend sideways when the wheel moves up and down. If the rubber can not bend sideways the spring will be bent in an S shape. Forcing a leaf spring in an S-shape is a good recipe for ruining the leaf spring including breaking.
Lancia must have known this. Still the buffer was used from the first Flavia in 1960 till the last Fulvia in 1976. Only for the Flavia Super Jolly Lancia used so called spring rollers. There is no page in all the Lancia parts books combined with more modifications than the page about the rollers in the Super Jolly parts book.
Some buy or make spring rollers for their Fulvia. Interestingly they use bearings meant for children toys rather than bearings which can carry the weight. The weight the roller has to handle is the same as the weight the wheel bearing has to carry. The latter almost has the dimensions of a truck bearing. I agree that wheel bearings spin at much higher rpm and have to handle axial forces as well but still.
So, the recipe is to use the 90mm one (the standard size Lancia used) and replace regularly. Drive and brake a bit before you judge the result. If the rubber has been too short and too thick and too hard for a long time (as seems to be in your case) the spring has to be tampered as well. The Lancia leaf springs are high tech. Very few who understand them and can do a perfect job in tampering.
If you take off the old buffers check if their length is equal. If not you most likely have vibration on the side of the shortest one (usually the RH one). Vibration does not only cause metal fatigue but als rubber fatigue.To limit peak loads on the rubber it is important to use monotube high pressure gas shock absorbers also called De Carbon shock absorbers. These are nicely progressive. The higher the load change the harder they work.
After driving a few 100 km's have the caster checked.
Those rubbers have always been an enigma for me.
Good quality natural rubber with the density and diameter of the buffers used by Lancia cannot work elastically. The limit is exceeded. So they deform permanently as you have noted.
Also the rubber has to be flexible and remain flexible. The length of half the transverse spring is much different form the length of the upper wishbone. The angle between the two varies when moving up and down. That requires a buffer which can still bend sideways when the wheel moves up and down. If the rubber can not bend sideways the spring will be bent in an S shape. Forcing a leaf spring in an S-shape is a good recipe for ruining the leaf spring including breaking.
Lancia must have known this. Still the buffer was used from the first Flavia in 1960 till the last Fulvia in 1976. Only for the Flavia Super Jolly Lancia used so called spring rollers. There is no page in all the Lancia parts books combined with more modifications than the page about the rollers in the Super Jolly parts book.
Some buy or make spring rollers for their Fulvia. Interestingly they use bearings meant for children toys rather than bearings which can carry the weight. The weight the roller has to handle is the same as the weight the wheel bearing has to carry. The latter almost has the dimensions of a truck bearing. I agree that wheel bearings spin at much higher rpm and have to handle axial forces as well but still.
So, the recipe is to use the 90mm one (the standard size Lancia used) and replace regularly. Drive and brake a bit before you judge the result. If the rubber has been too short and too thick and too hard for a long time (as seems to be in your case) the spring has to be tampered as well. The Lancia leaf springs are high tech. Very few who understand them and can do a perfect job in tampering.
If you take off the old buffers check if their length is equal. If not you most likely have vibration on the side of the shortest one (usually the RH one). Vibration does not only cause metal fatigue but als rubber fatigue.To limit peak loads on the rubber it is important to use monotube high pressure gas shock absorbers also called De Carbon shock absorbers. These are nicely progressive. The higher the load change the harder they work.
After driving a few 100 km's have the caster checked.
Re: S2 front suspension buffers
Thank you for the detailed response. I'll go ahead with the installation of the 90mm buffers.
The shocks in the car now have a fully exposed rod at the bottom end and an accordion style wiper seal that fits onto the upper tube. I've not seen that style in any picture so far.
The front left of the car is actually about 5mm lower than the front right measured from the ground to the wheel arch, and the front left buffer measures 61mm compared to the ~66mm for the front right. This slight lean is what prompted the whole investigation.
The shocks in the car now have a fully exposed rod at the bottom end and an accordion style wiper seal that fits onto the upper tube. I've not seen that style in any picture so far.
The front left of the car is actually about 5mm lower than the front right measured from the ground to the wheel arch, and the front left buffer measures 61mm compared to the ~66mm for the front right. This slight lean is what prompted the whole investigation.
Last edited by Nostromo on 17 May 2024, 04:08, edited 1 time in total.
Re: S2 front suspension buffers
Good idea to check the LH side for vibration. Might be tyres, CVJ's (inner and outer), hubs (if driving too long with a bad bearing, it may overheat and destroy the ring inside the hub, play on wheel bearing. brake rotors.
Re: S2 front suspension buffers
Success. Installed new 90mm buffers and shocks in the front. Car now sits perfectly level and rides well. The lower bushing was cut on the right side so the occasional clunk noise is gone.
I would like to add two photos, but got an error message that the files are too big. I guess this site doesn't automatically resize them. Any work around? I couldn't find a way to resize them on my phone.
I would like to add two photos, but got an error message that the files are too big. I guess this site doesn't automatically resize them. Any work around? I couldn't find a way to resize them on my phone.
Re: S2 front suspension buffers
Good to hear.
About uploading
I just checked with my IT manager. Automatic reduce should have been implemented. We will look into it.
In the meantime you can send the pics to someone through WhatsApp and ask the person to return.
Or send to me through WhatsApp +31653458044
About uploading
I just checked with my IT manager. Automatic reduce should have been implemented. We will look into it.
In the meantime you can send the pics to someone through WhatsApp and ask the person to return.
Or send to me through WhatsApp +31653458044
Re: S2 front suspension buffers
Downsized the images on my computer (site still returned an error for file size being too large).
So here you can see the old and new buffers, and the left buffer installed. Really happy with the attitude of the car now and the clunk from the torn lower shock bushing is gone.
So here you can see the old and new buffers, and the left buffer installed. Really happy with the attitude of the car now and the clunk from the torn lower shock bushing is gone.
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