Making the poly radius arm bushings...

ubercrap · Post by **ubercrap** » Tue Jan 10, 2006 9:47 pm

Looks crude, but should be effective.

raygreenwood · Post by **raygreenwood** » Wed Jan 11, 2006 7:50 am

Yep..you are on teh right track. But...be very carful on teh hardness. that bushing should not be much over 65-70 durometer shore A...or it will crack teh "eyte" on teh subframe in cold weather. Ray

ubercrap · Post by **ubercrap** » Wed Jan 11, 2006 7:55 am

It's pretty soft, 60 Duro.

raygreenwood · Post by **raygreenwood** » Wed Jan 11, 2006 10:32 am

Cool. I pretty much do the same thing. I use thicknesses of Urethane laminated together. I temporarily glue them to a block of wood. I have a hole saw that cuts the inner and outer at one time.
Also make sure that teh "centering ring"....that piece of hard polyethylene that is sandwiched between teh two donuts and snapped into the hole in the "ear" is good. This keeps teh rod end from contacting the metal of the eye...wearing out...and vibrating.

I had mine machined from delrin. They will last forever. I am experimenting with asimple delrin sleev...that slips over the end of the rod....goes through the middle of bothe donuts and alleviates the need for a seperate centering ring. Ray

ubercrap · Post by **ubercrap** » Wed Jan 11, 2006 10:35 am

The centering rings are present and look to be in nice shape.

Bill K. · Post by **Bill K.** » Wed Jan 11, 2006 2:20 pm

Looks great. Not crude at all.

I'll buy a set if you have one to offer.
-Bill

ubercrap · Post by **ubercrap** » Wed Jan 11, 2006 3:53 pm

OK, I'll get cranking tonight on some.

Wally · Post by **Wally** » Thu Jan 12, 2006 1:32 am

Looks very good! Nice to have an (better) alternative for these!
I hope they don't squeel.
Very curieus how they would work out on the road.

Tnx,
Walter

Guest · Post by **Guest** » Thu Jan 12, 2006 3:29 am

What you have in the other side, rubber. Does this also increase caster angle?

Guest · Post by **Guest** » Thu Jan 12, 2006 3:30 am

Anonymous wrote:What you have in the other side, original rubber ring or urethane? Does this also increase caster angle?

func412 · Post by **func412** » Thu Jan 12, 2006 3:31 am

Sorry, that was me...

raygreenwood · Post by **raygreenwood** » Thu Jan 12, 2006 5:21 am

Wally. I have about 7 years on mine. They work great. They don't have squeeling problems because there is very little rotational movement on them.

As I noted, the onlky things to watch for or worry about is getting them too hard.

The real "control" part of this pair of bushings ...is the forward most one. That one should be the harder of the two....if there are going to be any differences. This is because you do not want a lot of rearward compression of the forward bushing....because it alters the toe-in as you are driving.

With that in mind...the softer one needs to be in the rear. There has to be some "give"...especially when the suspension travels downward and both bushings compress against the metal in the center.

Urethane....hardens with age by an average of 5%...so keep an eye on them. In cold weather....urethane also temporarily can gain another 5-10% hardness. It is in this situation when the suspenion has to travel long on terrible roads that you can risk cracking the mounting point.

Since the forward bushing is most responsibel for control, I recommend making it of urethane...and teh leaving teh rearward one either very soft 40-50 duro urethane...or black 40 -50 duro rubber.

Yes...this is one potential way to gain some castor angle.....but at a risk. beware.

Putting shims behind the forward bushing will push teh contol arm fowrad slightly, increasing rake and castor. But...thgis also greatly increases pressure on the control arm bushing, accelerates wear to teh control arm bushing yoke, and wears teh shims out on teh radius arm very qucikly. The castor can also be temporarily lost due to road shocks and compression of the forward radius arm bushing.

The method Ubercarp is using to slide the subframe forward is the very best method of adding castor on this vehicle.

If your radius arm droops when looked at from the side...or rattles up and down in its mounting socket....the centering ring needs to be replaced. Ray

vwbill · Post by **vwbill** » Mon Jan 16, 2006 10:32 pm

Great job Uber!!! Those look sweet!! How do you know the hardness??
Is it a standard for that material? Where did you get that stuff? If you are selling let us know! Thanks again for another great post and picture and great comments and replys! bill

raygreenwood · Post by **raygreenwood** » Tue Jan 17, 2006 6:02 am

Its worth it to check the hardness. there are several baseline formulas for urethane. among those baseline formulas...there are literally thousands of custom variations. There are cast, centrifugal cast and injection molded versions of urethane.
I use sheet Urethane that is actually made from squeegee material for screen printing shops. This is because the "good" stuff...is within a known range of durometer.
All urethanes have a range of variation in hardness. They tend to have a +/- of 5 durometer. That means an "average" cheap piece of Urethane of 60 duro can have a range of about 10 durometer with this plus or minus. It can range from 55-65. The squeegee rubber...the better stuff.....generally has a range of +5 durometer/-0.

It gnerally comes by the foot, in a standard thickness of about 10mm and a standard width of about 50mm.
It also comes in dual durometer varieties. This is a cast sandwich of say 65 duro on bothsides of the outside and a 90 duro rib in the middle.
I generally use a stack of two pieces for each bushing. Ray

MGVWfan · Post by **MGVWfan** » Tue Jan 17, 2006 8:48 am

Most excellent job Uber! That's next on my list of suspension mods, along with the lower control arm bushings.