Rear Suspension Foam Washers

[dave.armstrong]

Do any of you know the thickness and size of the foam washers that should be fitted next to the suspension bushes on the rear of an Alfasud?

I want to make some.

Thanks

[PETROLHEAD]

I might even have some of those dave.

Have you got a quick picture for me to compare?

[dave.armstrong]

Mine have all disappeared

[alfadave]

Use feeler gauges to measure the gap?

[PETROLHEAD]

Yeah i guess thats the case with most of them by now.

I've never had a sud/sprint yet that's still got them.


However, i have a sneaky suspicion ive got a packet or two of brand new genuine alfa jobbies, i think they're 8 per pack by memory which would make sense!


I'll have to dig them out for a picture

[dave.armstrong]

Great!

Thanks Shrew

[PETROLHEAD]

It might be later in the week before I'm over there dave, are you in a rush?

[dave.armstrong]

No rush

thanks

[Crank]

There are a few crumbs remaining of the foam washers on my 'get it finished one day' Sprint restoration and I have been wondering if its worth making up some new ones. But I can't decide as I don't know why they were fitted in the first place ! My guess would be that they are there to prevent clonks when the watts linkages are twisted under extreme cornering with the original softish rubber bushes. Does anyone have any other suggestions ?

[PETROLHEAD]

Beats me what they're for?

They're not substantial enough to prevent or dampen any movement or noise whatsoever in my opinion.

If its open cell foam, all it would do is trap damp, so I'm struggling to find the positive!

[dave.armstrong]

They are pretty useless really.

But in my younger more reckless days they used to stop metal to metal contact due to the soft bushes when cornering hard.

The Watts parallelogram make the arms twist at weird angles rather than just up and down and back to front.

Now I don't screw it round corners as hard it doesn't happen much.

[Crank]

I don't think I'll be needing them anymore either. Due to a combination of age, traffic and the poorly maintained roads in my part of the world.

[alfadave]

Just fit some large plastic washers if you want to replace them?

[Gary Orchard]

The part is still available new from Alfa - not cheap at £5.32 each and they come in a packet of 5 so you would need 2 packets
The part number is 60501922

[PETROLHEAD]

I'll be looking for my stock tomorrow, and if i find them they will be much cheaper,

£5.20 each!

[dave.armstrong]

Bargain!

[PETROLHEAD]

A little bit like these then?

2 x 5 packs, unopened, genuine beauties!

[dave.armstrong]

Hi Shrew

Please could you measure them for me.

Outside diameter

Inside diameter

Thickness

thanks

[PETROLHEAD]

Hi dave

I dont have my verniers with me, out the workshop till later in the week or weekend now, but i have the foam washers with me, ill have to ruler them for you as best i can.

Alternatively you can have this lot (10) for 20 quid delivered?

[dave.armstrong]

Hi Shrew

A measurement taken by ruler will be fine.

Thanks for the offer to buy - great price but unfortunately I need more than 10 so once I have set up to make a batch I can churn them out fairly quickly and they will all match.

Thanks again

Cheers

Dave

[PETROLHEAD]

No problem dave

I'll measure them up for you anyway, sit tight

[PETROLHEAD]

Ok Dave

foam washers are the following dimensions.

OD = 55mm
ID = 16mm
Thickness = 3mm


Its rather an odd material Dave, feels like both foam and felt fibre sort of thing?

best of luck mate

[dave.armstrong]

Thanks Shrew that's great.

I really appreciate it.

I am going to make them out of neoprene foam so hopefully they will last longer!

Cheers

Dave

[dave.armstrong]

I finally got round to making and fitting the foam washers.

I spent ages playing around jacking up the rear of the car at different points to see the Watts linkage working (I know I'm sad).

James Watt was a very clever man!

Its amazing watching the arms twist and turn differently depending on if the suspension is completely compressed or extended. You can also see the flexibility of the bushes giving an element of rear wheel steer to the dead axle.

The arms do make metal to metal contact with the mounting points in extremis.

After fitting the washers the ride at the rear seems more refined. Probably all in my mind I know, but the squeaking little mouse noise from the rear which used to drive me mad has gone.

I have read that when the Phoenix group took over Rover to save money they ditched lots of little bushes and felt pads to save money and that the cars in that era felt much looser and rattly.

Also, I remember years ago when it was quite common for insurance companies not write a car off but to have it reshelled if a new shell was available to purchase. Most people wanted to avoid this as no matter how well it was put back together the cars always felt loose and rattly as the little pieces of felt and foam were not even available as part numbers and thus were not fitted.

As you will probably gather from this post the rain was pissing down in Manchester this weekend and there was nothing on the telly. So, after reading Colin's book I was inspired to have a play with my clever little Sud.

I drove it a lot too!

[Crank]

Thats very interesting. I realised the importance of the soft rubber bushes after I fitted polly ones and ruined the handling. Sorry if that comment upsets anyone but that my opinion. I remember stories about Suds failing the MOT as testers thought that the soft bushes were worn when they twisted the Watts arms as they did not realise they are meant to allow quite a lot of movement. That did not stop me from fitting polly bushes though, I assumed they would be an improvement. I then realised I had made a mistake but I have never understood why and frankly I still don't! But I am convinced that the softer bushes are one of the key reasons that the Sud handles so well.

[Crank]

While on the subject of the subtlety of the Suds rear suspension design. I remember an article in the AROC magazine a few years ago about this, by one of the drivers of the Alfa UK Napolina sponsored Sud, which raced in the British Saloon Car Championship back in the 1970,s. Their first car was a very early car and apparently the very first cars made before sales began in the UK, had a shorter leading watts linkage in front of the wheel and the attachment point on the floorpan was closer to the axle. This was the original design but the car was so prone to oversteer that some customers complained that it would spin. As there had been a few accident Alfa decided it was a safety issue and lengthend the front Watts links to solve the 'problem'. None of the later Suds that the team raced handled so well. When they realised why, the team modified them to the old set up as it was quicker. That might give some of the racers some idea's. All you need to do is find a very early car in Italy to take some measurements. Come to think of it there is one in the Alfa Museum.

[dave.armstrong]

I definitely think that the compliance built in to the Suds suspension helps it handle so well.

It was intriguing jacking it up and watching the movement at different points.

I had a 916 Spider and most enthusiasts reckon that these handle better on standard bushes because of the element of rear wheel steer.

I have attended a couple of talks given by Peter Cambridge.

Peter did the development work on the Brera S whilst he was at Prodrive.

He is very scathing on polybushes and explains the amount of work that goes into developing standard bushes.

Apparently, they have different resistance on compression and extension.

And they have different resistance from different angles ie side to side compared to front to back etc.

Not sure Alfa were that advanced in 1971 though!

[Crank]

Thats interesting. Car manufactures do of course spend a lot of time and money developing new models and I am always reluctant to move away from the original specifications. Its interesting to note that the bushes in the front Watts links are thinner than those fitted to the rear links and there must be a good reason for that.

[alfadave]

If you look at Tims Alfasud pages
and click on Technical Data

there is a cutaway sideview which shows the front end of the front Watts linkage, well back from the front of the tank.

quite different from the actual production position I think?

Dave

[Alfasam]

I think there is possibly another twist to the story about the modifications that Alfa made to the rear leading arms on the series 1 Sud's.

I came across a strange anomaly whilst going through some new old stock parts I purchased as a job lot from a guy in Italy a few years ago. In amongst the parts was a left hand rear stub axle carrying an original Alfa Romeo part number sticker, showing the no. 700604. The part immediately looked odd to me, seeming to be somewhat smaller from how I remembered the used ones that I took off my Super for repair and powder coating a couple of years ago.

Sure enough, when I compared it to the ones off the Super it was approx. 30 mm shorter between the top and bottom arm fixing points. I then checked my Ti S1 parts book from Nov 73 and found that the original parts from 1972-73 are indeed shown as no's 700604 + 700605 right/left whilst on the Super fiche from 1977 they are no's 701256 + 701255 right/left

Seemingly, the changes in dimensions between the top and bottom arm positions on what is effectively the crank in the Watts linkage mechanism would alter the degree of anti-roll effect produced in the rear axle torsion beam, as the suspension is put under increasing load on one side or the other. If the leading arm lengths were also changed as described in the previous post this would appear to link-in with the change in dimension I discovered had been made to the rear stub axle back plates.

It is the case that some early road testers of the Alfasud (particularly the Ti) found that it could be made to consistently over steer if deliberately provoked in the right way. In particular the ex racing driver Paul Frere who wrote for Motor was quite critical in late 1973 when testing the Ti for the first time at the Naples press launch. He stated that in his opinion a front wheel
drive car that had over steer as its ultimate handling characteristic was too sophisticated for ordinary drivers who were much safer with a consistent bias towards understeer. He commented that in his opinion Alfa should modify the car accordingly to make it safer in the hands of the general public. It seems Alfa must have listened to him

As I am sure many on the Forum are aware Peugeot had just the same issue with the 205 series, particularly the 1.6 and 1.9 GTi cars which were very twitchy at the rear and could soon bite the unwary.