Bushings for Type4

[VW 612 RS]

Hello!
Since there is no parts to get for the VW 411/412 I have started to make my own bushings from Polyurethan.
Even the "pyramid" bushings who holds the crossmemebers in place are going to be reproduced. Front end rear.
I´m planning to produce all the bushings. Have my own metal machine shop
So far it´s just been made for the rear axle. My friend "Hulken" are going to test this bushings on the road.

The big question. Is there anyone who also want this type of parts?
I´m starting to make a website where you can just click on the parts you want and pay with Paypal.
This is not a business to make a lot of money of It´s just a hobby and want to offer parts to other Type4 owners.

Thers is different hardnes of Polyrethan. At the rear axle I have used hardnes 95. This is very similar (maybe the same) to the VW type1 bushings.

This was my wife's idea. Why don't offers this to other owners also


And at last.
My 612 is at the paint shop so this summer I hopefully get the car on the road

Best Regards
VW 612 RS

Hans Olav Strand

[bradey bunch]

I would take a complete set of bushings depending on price. (maybe 2 complete sets....)

Braden

[Single 60]

I'll take a set keep us informed.

Thanks Terry

[raygreenwood]

I have made most of the bushings already. Polyurethane is not ideal. There are many recipes for urethane. The problem is that they tend to start squirmining under load in the maon positions where you find them in 411/412....the front control arm and rear trailing arms.

Also polyurethane begins to harden at a rate of about 3% per year. During this many recipes also shrink a bit. It gets squeeky. Delrin and/or glass filled delrin work much better for front and rear control arm bushings.

For rear beam pyramids (same as front sub frame pyramid)....urethane is too hard and does not conform well. It tends to compress to a certain point and then stop....which makes the sub frames out of alignment. If you do use urethane, the durometer would need to be 50 duro or less (shore A). this means that it must be a casting...not a machind part. urethane does not machine accurately below 80 duro.

For the radius arm bushings/donuts on the front end.....urethane can be used if its sandwiched with something softer and does not use the urethane in contact with the subframe eye. The urethane hardens considerably in cold weather and will crack the subframe eye on hard bumps.

Urethane cannot be used for the outer links. It snaps them like twigs in cold weather. I almost rolld the car this way.

Urethane works very well for the sway bar bushings. If you line them with bondable teflon dring casting...they work well. Otherwasie they will squeek like mad when they harden up. Ray

[fusername]

trust ray, but don't let it turn you off! do this. I don't even have a T4, but anything that keeps these thigns alive and your brain working is wort hit!

[Devastator]

I have made most of the bushings already. Polyurethane is not ideal. There are many recipes for urethane. The problem is that they tend to start squirmining under load in the maon positions where you find them in 411/412....the front control arm and rear trailing arms.

Also polyurethane begins to harden at a rate of about 3% per year. During this many recipes also shrink a bit. It gets squeeky. Delrin and/or glass filled delrin work much better for front and rear control arm bushings.

For rear beam pyramids (same as front sub frame pyramid)....urethane is too hard and does not conform well. It tends to compress to a certain point and then stop....which makes the sub frames out of alignment. If you do use urethane, the durometer would need to be 50 duro or less (shore A). this means that it must be a casting...not a machind part. urethane does not machine accurately below 80 duro.

For the radius arm bushings/donuts on the front end.....urethane can be used if its sandwiched with something softer and does not use the urethane in contact with the subframe eye. The urethane hardens considerably in cold weather and will crack the subframe eye on hard bumps.

Urethane cannot be used for the outer links. It snaps them like twigs in cold weather. I almost rolld the car this way.

Urethane works very well for the sway bar bushings. If you line them with bondable teflon dring casting...they work well. Otherwasie they will squeek like mad when they harden up. Ray

So, what material is a good substitute?
Nylon 6,6, Delrin, UHMW, Delrin AF, Rulon, PEEK, PTFE, ...?
FWIW, I use oil impregnated nylon for my T1 trailing arm bushings.

[raygreenwood]

I have made most of the bushings already. Polyurethane is not ideal. There are many recipes for urethane. The problem is that they tend to start squirmining under load in the maon positions where you find them in 411/412....the front control arm and rear trailing arms.

Also polyurethane begins to harden at a rate of about 3% per year. During this many recipes also shrink a bit. It gets squeeky. Delrin and/or glass filled delrin work much better for front and rear control arm bushings.

For rear beam pyramids (same as front sub frame pyramid)....urethane is too hard and does not conform well. It tends to compress to a certain point and then stop....which makes the sub frames out of alignment. If you do use urethane, the durometer would need to be 50 duro or less (shore A). this means that it must be a casting...not a machind part. urethane does not machine accurately below 80 duro.

For the radius arm bushings/donuts on the front end.....urethane can be used if its sandwiched with something softer and does not use the urethane in contact with the subframe eye. The urethane hardens considerably in cold weather and will crack the subframe eye on hard bumps.

Urethane cannot be used for the outer links. It snaps them like twigs in cold weather. I almost rolld the car this way.

Urethane works very well for the sway bar bushings. If you line them with bondable teflon dring casting...they work well. Otherwasie they will squeek like mad when they harden up. Ray

So, what material is a good substitute?
Nylon 6,6, Delrin, UHMW, Delrin AF, Rulon, PEEK, PTFE, ...?
FWIW, I use oil impregnated nylon for my T1 trailing arm bushings.

As I noted....glass filled Delrin seems to work very well. 6.6 nylon would be a bad choice for any suspension compoent. Too many issues with various salt reactions and water absorption. If you need to use nylon use nylon 12.

Nylons are not great for control arm bushings. The surface friction is too low. In these bushings you need a light pres fit. You are wanting to make sure that the bushing does not start squirming or turing in the bore of the arm...or around the steel bush in the center. When that happens it either starts to crack or gets sloppy because of quick wear.

A number of years ago while I was looking around at all of these same plastics while trying to figure out what I was going to make my bsuhings of...i took notice that a lot of the aftermarket hi-po bushings for the WC cars and the Audi S-cars were being made out fo glass filled delrin... and these have performed very well and they are easy to machine.

I also agree with what fusername noted. I'm not trying to turn you off. Any new bushing is far better than driving around on bad ones and breaking more parts attched to them. Just letting you know that in some cases...urethanes for instance....your result may be less than ideal and in some odd cases may even have adverse reactions.

But....in the beginning I cast most of my bushings from urethane. Easy to cast...hard to control durometer....but they worked and kept me going. So any method is good experience.

The nice thing about some common casting urethanes is that you can buy additives to reduce durometer. Typically most casting compounds are about 80 duro or harder. the problem is that durometer is not all you really need to worry about. Rebound....or elasticity...or flexural modulus is also important. Unless you are buying very high dollar engineered compounds.....those things are hard to control. Ray

[Hulken]

Since Hans Olav are gonna make me a set of bushings to try out, we really want to go the right way on first atempt. So, Ray and everyone else with experience, here are some questions;

Glass filled delrin, is it supposed to be bone hard? I bought some from ebay, but didn't think it would be this hard?

If we use this Delrin, my concern is that it would be too hard. The original rubber bushings do flex, If we use my Delrin they won't flex at all! But maybe that's ok, the bushings are only working as pivot points?

What about all others mentioned Ray, do you have some links to materials you advice us to use?

Regards
Arild

[Devastator]

Hope I can post this:

[raygreenwood]

Since Hans Olav are gonna make me a set of bushings to try out, we really want to go the right way on first atempt. So, Ray and everyone else with experience, here are some questions;

Glass filled delrin, is it supposed to be bone hard? I bought some from ebay, but didn't think it would be this hard?

If we use this Delrin, my concern is that it would be too hard. The original rubber bushings do flex, If we use my Delrin they won't flex at all! But maybe that's ok, the bushings are only working as pivot points?

What about all others mentioned Ray, do you have some links to materials you advice us to use?

Regards
Arild

Yes...they are rock hard. The object is to get something that transmits vibration less than steel....but does not have teh nasty flex that the stock ones did,. The stock ones were too soft. You want the control arms to stay in a stable psoition. The radius arm bushings you want flexable material in.

If you are really worried about vibration you can make delrin bushings to fit around teh steel bush on the inside and keep them just the lenth of the width of the control arm and put a urethane disc aroun the outside where it faces the yoke in the center subframe.

People had teh same worry with the solid bronze idler bushing (a must have).....until they real;ized that VW replaced all of them with bronze in about 1978. You will never feel it.

These bushings are an upgrade. They will make your suspension slightly stiffer handling....and thats better. Ray

[bradey bunch]

I would much prefer delrin to urethane for any of the pivot points. Aside from heim joints I believe it is about the most precise bushing material.

Braden

[VW 612 RS]

The reason I would choose to use Urethan is because this type of urethane is upgrade for all vehicle and it´s well tested.
If you visit the Poweflex website you see all the bushing is made of Polyurethan (95).
Summitracing, Energisuspension are using the same products
I bealive there is a reason why all the companies choose to use this type. It´s have been thoroughly tested before they start a large production line.
I wisiting a company today not far from where I live.
They´r making Polyurethane and they said this is the only upgrade. Delrin is way to hard.
They have been casting Polyurethane for 30 years and said the only cold problem is when it get below -40 degrees celcius (-40 fahrenheit?) they became a little bit stiffer. When I asked about Polyurethan will be harder by around 3% pr. year they said that´s wrong.

The upgrade for VW type1 is used of Polyurethan.
My VW 1303 has all bushings from Polyurethan and it still works

So why is the VW 412 so "special" and can´t use it?

Anyway, I will make a complete set for my 612 and test it before I start any production except for the donuts.
The will remain in stock so far

Best Regards
Hans Olav

[Bill K.]

I like polyurethane for the sway bar mounts.

Delrin control/trailing arm bushings are a common upgrade over polyurethane: Rubber < Polyurethane < Delrin. Harder bushings maintain wheel geometry (camber/toe) during high speed cornering resulting in improved, and more predictable, tire grip.

Examples for 911 & 914:


914 parts from http://www.tangerineracing.com




Works great on 411/2 also! I used 1-1/2" diameter glass filled delrin from McMaster Carr (http://www.mcmaster.com/#8719K16).

412 Front (with slotted carrier and eccentric head bolt for camber adjustment):

Control arm bushings2.jpg

412 Rear:

rear wishbone bushing installed.jpg

rear wishbone bushing.jpg

[raygreenwood]

Nice pics! Thanks Bill!

A long time back I had cast rear control arm bushings from urethane with etched teflon rings on the inside. Urethane works really nice for sway bar bushings. Most of the ones from the known manufacturers uesed to squeek for many of the same reasons my first ones did before I put teflon in them.

Its great for sway bar bushings because even as it ages a bit more hardness wont really hurt sway bar bushings.

To answer he question as to why not use urethane for other bushings when companies like topline are using it as an "upgrade".....I do not really consider what topline is using for supers as that great of an upgrade. Not insulating what they make...just that I have found many of what topline and Energy makes to be to hard after a short period of time. its brutal on other parts.

Also...there are "0" OEM parts using urethane. its life for a control arm bushing and the issues it has with changing hardness are too hard to warrant. Plus...urethane is hard to dial in during compounding.

A bit more.....you need to understand how the 411/412 front and rar control arm bushings were built. many other factory bushes are made this way and its a great method for general use...and even high performance if designed right.
The bushings on your 411/412 when youdisect them....are pressure cast and bonded synthetic black rubber. The control arm bushings are an external tube that is pressed into the cavity in the arm. It has a very thin band...about 5mm...of rubber surrounding about a 7mm wall thickness steel tube bushing.
The important thing to know is that during molding....the inner bush and outer tube are put into a die. Rubber resin under very high pressure...specifically engineered for the end product ...is injected in and then heated.

By adjusting the injection pressure they can adjust the final durometer, rebound and elasticity of the final product at will. Urethane can do that to....but it shrinks with age...thats a problem.

Why is the 411/412 different? Because it has some of the longest control arms you will likely see. They also pivot at the center. This creates huge leverage on the control arm bushings, radius arm bushing and idler arm bushing. So...as you drive forward..thrust on the wheels spreads your toe-in outward. This impinges on the control arm bushings...loads the radius arm bushings....and the control arm tries to pivot in space. This leverage over time works the bore in the control arm oval. It insome cases..allows teh entire metal outer tube to slip. Usually the arm slips forward andis then rubbing on the mounting yoke.
In most cases its the rubber bushing that starts to shred.....and slips forward and rubs on teh yoke.

Also the 411/412 has just about the longest strut cartridges you will ever see...adn one of the longest center tie-rods. It was just not the geratest geometry for soft bushings.

Urethane will work well....better than stock rubber....but not for the long haul. How often do you want to do this?

The delrin has a proven track record for front and rear bushings.

Also....with stock bushings....I have found that when you move to a larger tire.....the 205/60-15" tire on 5" x 15" wheels work superbly on the 411/412.....the extra thrust generated by the tires flexes teh stock control and radius arm bushings harder. For best results you need about 1.0-1.5 degrees more total toe-in. With delrin control arm bushings you can actually use slightly less toe-in than stock. Ray

[Hulken]

Looking good Bill! Did you make front and rear delrin bushings 100% the same dimensions? Did also make them the exact lenght as the metal bushing inside them?

Would also like to se some detailed photos of the slotted carrier and excentric head bolts!