Front end Bushings on German ebay

[Lahti411]

http://cgi.ebay.de/VW-411-412-Satz-Fahr ... 3a638b6266

Interesting...

[wildthings]

Wish someone would offer these on the left side of the pond.

[Hulken]

Wish someone would offer these on the left side of the pond.

BillK - where are you?

[raygreenwood]

These ar actually easy to make. You want them made of glass filled Delrin for the control arm bushings. Any machine shop can do them for you quite cheap. The radius arm donuts need to be under 70 durometer in hardness. I do not recomend urethane unless you cast them yourself (pretty easy). You can have these made from most rubber shops from 3/4" thick black Buna N rubber at about 55 duro. Ray

[Hulken]

Delrin on the way from US....

[Hulken]

Could the control arm bushing be made out of this? http://www.prothanesuspensionparts.com/ ... rod=DIYMMI#

Make som sort of moulding and just pour this stuff in?

[raygreenwood]

Could the control arm bushing be made out of this? http://www.prothanesuspensionparts.com/ ... rod=DIYMMI#

Make som sort of moulding and just pour this stuff in?

Yes they can....but you would have to have the right urethane compound with the right durometer and rebound modulus. As nice as prothane is...their urethane formulations are pretty basic.

Also the 411/412 bushing with any suspension mods is too soft. Urethane would be too..unless is is ugly hard. Urethane has a poor life span because all urethane's start to harden up as they age...usually about 2-5% per year until they have squeaking and fit problems.

The other issue is that the configuration stock bushing shows that it was meant to be very stout because there is very high leverage on the long control arms....and even they were not good enough. They typically start getting cracks and slip to one side before 50k miles.

The stock bushing is about 4/5th's steel center bushing tube, about 1/8" of pressure bonded rubber and about a .020" thick outer tube. It makes a far better bushing to simply keep the center tubes or get something like it and have new surrounds made from glass filled delrin (cheap and last forever).
This is what a lot of the mid to late 90's audi's used on performance suspension systems. Ray

[Hulken]

I was thinking of the donuts, the others I will make of delrin allready laying around waiting. By the way, got 2 hours in the garage working on my 412 bort yesterday and today...

[raygreenwood]

I have made them already for my car quite a while back. You needto be really careful with the radius arm donuts. The stock ones were about 50 durometer. There were plusses and minus's to the stock ones.

The plus: they were soft enough to keep from cracking the "eye" portion of the ssuspension subframe in very cold weather when you go over hard bumps.

The minus: They were too soft.... they were soft enough that when the suspension went to maximum compression it loaded the radius arm rod too heavily against the plastic centering ring in the mounting eye. Typcially these centering rings got maybe 50K miles before just grinding out.

Some of this was just the design. The dish on either side of the eye for the track control donuts to sit in was just not deep enough to keep the donuts from slipping downward with age to the 6:00 position....making the load against the plastic centering ring very high. Add to that the centering rings were too soft...being polyethylene or polypropylene.


The problem with the hardness of the donuts is that the vast majority of comon urethane castings that will have spring rebound suitable for long life in this area...will also have too soft of a durometer (typically about 60+). Most catables will be in the 75-80 duro range.

I had a set machined from 80 duro back in the 90's. The first freezing day outside...it snapped both eyes when i went over a moderate bump....effectively wrecking the front end. I barely got home...and the material teh subframe is made of is not readily weldable. I was lucky to have a spare from the wrecking yard.

The problem is that the disc portion of the radius arm that bears against the back side of the donut.....when you go over a bump....simultaneously rotates in the eye...and changes angle in relation to the eye when looking at it from the side...say through the wheel arch. that means when the control arm moves upward....the gap between the top of the backing disc on the radius arm...at the 12:00 position....narrows considerably. Are you with me?

When this happens with a 50 duro stock rubber donut...its no big deal...hot or cold. However with 75Duro urethane....its a HUGE load against very hard urethane. Too much load.

However I have a new set I am working with and should have them together in the next month. They use a .030" thick bonded teflon outer face where they contact the disc and the centering ring in the eye socket. They have an approximately 1/4" thick center layer of 50 duro synthetic rubber and an outer layer on each side of 70 duro urethane. I will put together a pictorial on construction. You can get the raw materials in virtually any rubber shop.

My centering rings I had made of Delrin ages ago. Great mod.

In a further modication i am working on a set of radius arms to remove the flange or disc. I am replacing it with a sliding bronze 1" diamter half ball locked in place with a shaft collar. It gets rid of the problem of the changing angle of the plate/disc and allow the use of stifffer donuts without risking damage. An easy and cheap mod to do with just hand tools and drill press with much more effective track control. I will post a pictorial soon. Ray

[Hulken]

Sounds good Ray, looking forward to your pictorials on this and other issueswe have to overcome. I'm collecting parts to do a college front and rear end update off the car to keep it in traffic while doing modifications. Problems here in "little" Norway is to find all the strange material you over there seem to have available all over the place....

I guess with the right material, all needed to do is to use the holesaw in correct inner and outher dimensions. Do you have a link to someone selling this material online Ray?

[raygreenwood]

Yes....i will find you some links to the materials in Europe as I go. There are actually many...and you will want to buy them in Europe due to REACH law reqyuirements on shipping/importing chemicals.

In a pinch.....as you note....you can make suitable copies of the originals simply by getting black rubber 50 duro sheets of the proper thickness and using a hole saw. I made my first ones like this and they worked well.

The easy way to make them is to take the sheet rubber and use standard superglue (cyanoacrylate adhesive) to glue the rubber flat to a block of wood. Then hole saw the center out first so the center drill bit makes a guide for the large hole saw center bit so you can cut the outer. Use a grinder to radius the outside.

I will also be making sets of bushings for others cars for sale. They will be very affordable because I will charge materials and shipping only. Its simpler to cast "sets" of them and buying materials is cheaper when you get larger quantities....so if I make them for myself and have waster left over material...its actually more expensive for me. Ray

[Hulken]

Sign me up for at least one set...