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[elvin315]

I hate to throw more fuel on this fire but I found poly/ball joints on an off-road site. They use Chrisgixer's method of a steel ball insert sandwiched between 2 poly races, inside a steel casing. The bolt has a zerk fitting for lubricating the ball. They come is 2 flavors:

2 inch (50.8mm) OD w/ 7/16 inch (11.1125mm) bolt
2.5 inch (63.5mm) OD w/9/16 inch (14.2875) bolt

Neither comes close to our serving our purpose but here's the kicker. They are rebuildable, all the parts are available separately. They use snap-rings and washers to lock the ball and races in place. Maybe we could combine the 2 inch OD with the 9/16 inch ball and races to make one bushing that with a little machining would solve our problem. The outer case is meant to be welded to fabricated control arms and looks pretty beefy. It should stand up to a little shaving to bring it down to 49mm. Likewise the 2.5 in. poly races could be shaved down to fit the 2 in. casing. They are designed for the rigors of off-road duty so the should hold up nicely on-road. What do you think?

http://www.4wheelparts.com/Fabrication-Tools/Flex-Joints.aspx?catID=86&subCat=528&ptID=101460&pg=1

2 in./11mm:


2.5 in./14.3mm:


Exploded View:


9/16 in./14.3mm Ball:

[elvin315]

I've hit the jackpot today! If we can't find a way to use one these flex-joints or poly-joints for our cars then we may as well give up. The poly-joint is similar to razzo's method but the poly insert is shaped with voids to provide room for flex. Plus it uses the zerk bolt for lubrication at add extra slip like the GM bushing's silicon goop.

http://www.daystarsuspensionparts.com/universal-flex-joints.asp

Daystar KU70001BK 2.0 Inch Poly Flex Joint


Daystar KU70003BK 2.0 Inch Poly Joint


Greasable Bolts:
http://www.daystarsuspensionparts.com/Universal-Greaseable-Bolts.asp

[05omegav6]

I want to believe, I really do... but...

1. The smaller one would be perfect, the core needs 2mm shaved off either end. No biggy.
2. The outer diameter of 1.87" translates to 47mm so 2mm too small. Bugger.
3. What application is this designed for? Will the loads force it apart as Chris found with his hybrid ones?
4. Will the hollow bolt survive the fitting torque and operating loads?

 

Looking at the latest link, the top one is indeed promising, just needs a turn on a lathe to drop the OD to 49mm Questions 3and 4 still stand though...

The bottom suggestion offers little or no gain over the Black Sierra TCA bushes I have fitted

[elvin315]

I think I can answer numbers 3 & 4. These things are made for big fat American 4X4s and you know us 'Muricans love to bash our trucks over hill and dale (not me of course). I'm sure they'll hold up to us wannabe sporty car racers.   

I love the tech of the Poly-Flex with its shiny silver ball ( I like shiny things) but 12mm bolt bothers me. Mixing up parts from the 2 in. and 2.5 in. and modifying them all to fit together is an extra pain & expense, and then it might not work for us.

The simpler Poly-Joint's steel case could easily be shaved down to 49mm and its poly insert drilled to take the bigger 14mm bolt w/tube. The voids around the insert would allow it room to flex and deform. The TCA bushings are designed as pivot joints and therefore not as flexible when used in the vertical position. Considering its intended use as an off-road  joint, maybe the firmness of the insert is less then the ones you and razzo are using, lessening the bending force on the wishbone. Maybe.

[chrisgixer]

Slap the centre in the lathe, bore to the right diameter, then turn a collar for the outside. Job done, bish bash bosh.

Away you go then. £115 to find out

[05omegav6]

I think I can answer numbers 3 & 4. These things are made for big fat American 4X4s and you know us 'Muricans love to bash our trucks over hill and dale (not me of course). I'm sure they'll hold up to us wannabe sporty car racers.   

I love the tech of the Poly-Flex with its shiny silver ball ( I like shiny things) but 12mm bolt bothers me. Mixing up parts from the 2 in. and 2.5 in. and modifying them all to fit together is an extra pain & expense, and then it might not work for us.

The simpler Poly-Joint's steel case could easily be shaved down to 49mm and its poly insert drilled to take the bigger 14mm bolt w/tube. The voids around the insert would allow it room to flex and deform. The TCA bushings are designed as pivot joints and therefore not as flexible when used in the vertical position. Considering its intended use as an off-road  joint, maybe the firmness of the insert is less then the ones you and razzo are using, lessening the bending force on the wishbone. Maybe.

The TCA bushes that I am using don't stress the arms in same way as Razzos blocks, as they allow the full range of movement. They are a push fit, and are the same diameter and height as the original GM bush.

The issue with the simpler ones you suggest is that no one knows how much the flex/deform, which is how it has taken 4 stages (including Chris' ) to get to what's fitted on mine. They are however the only ones that might fit the wishbone, the others being too small

I'm struggling to see where those bushes might be used on a 4x4 axle locating rod perhaps

[aaronjb]

Slap the centre in the lathe, bore to the right diameter, then turn a collar for the outside. Job done, bish bash bosh.

Away you go then. £115 to find out

Sod that, I'm fine with my Elite handling like a barge.. (and have new GM bushes in the boot of the M3..)

[elvin315]

The TCA bushes that I am using don't stress the arms in same way as Razzos blocks, as they allow the full range of movement. They are a push fit, and are the same diameter and height as the original GM bush.

The issue with the simpler ones you suggest is that no one knows how much the flex/deform, which is how it has taken 4 stages (including Chris' ) to get to what's fitted on mine. They are however the only ones that might fit the wishbone, the others being too small

I'm struggling to see where those bushes might be used on a 4x4 axle locating rod perhaps

The bushings are used when fabricating control arms and/or locating arms for serious off-roading. These 4 wheeling fanatics fab suspension pieces to lift their trucks much higher than stock and to survive the intense shocks and stresses, real or imagined, that their vehicles may encounter. I haven't spoken to the manufacturer with regard to their bushings' Shore Hardness Index but when you compare the weight of a Ford F150 4X4 to that of an Omega/Catera I think our cars couldn't possibly flex these bushings to the point of failure.

After seeing the damage to razzo's wishbone I'm weary of using a solid poly bushing such as the ones you're using. I don't know how the highways are treated during the winters over there but here they spread liberal doses of rock salt to melt the ice & snow. The chances of salt corrosion damage is high, and then adding the type of stress a solid bushing places on the wishbone is just too much risk for me.

When I'm ready for new bushings I think I'll go with the Poly-Flex option, unless you guys come up with something better.

[chrisgixer]

It's like you've been reading my history Elvin.

As I recall, I prety much concluded, after looking at those 4x4 bushes, that the main restriction or concern is the height of the void in the omega subframe. There isn't the space to fit the metal encapsulated ball joints in the space available.
 
Looking at it another way, make a ball joint, in the correct dimensions. Draw it out even. By the time the ball is small enough, on a 14mm bolt, with a tilt angle needed, there is very little material left, to hold the metal ball in the poly.

We at basically looking at a ball joint, with dimensions that don't work for a ball joint. At that point, IMO, we have to accept one if two options. Find the nearest sized poly ball joint and adjust the sizes of the wishbone AND the subframe to fit. Or, stick with rubber bushes.

Thinking further. If a ball joint was made to the same dimensions as the oe rubber bush, the ball could easily pop out. Now, wether there are appropriate forces to make that happen is another story.

I have some pics somewhere.

[chrisgixer]

Forgot up add, the reason the oe rubber bush works at all, IMO, is because it's bonded. Otherwise it would pop out it seems to me.

[chrisgixer]

Drawing shows 20 degrees of tilt and a 2" bush body



Omega bush body height is 25.6mm or the that is the height of the wishbone void anyway.


Which means, by the time the wishbone is fully tilted we get this much gap, roughly, between the wishbone and the the subframe. Its tricky measuring this gap in an actual subframe as its concealed, but you get the idea.


So, by the time the bush body height is narrowed down to 25.6mm... Ok let's say 30mm as there is a bit of room, highlighted by the screw driver, by the time the poly surrounding the ball is added, there's not much poly in contact with the metal ball. Certainly less than the 2" 4X4 bush.


If that makes any sense at all.

[chrisgixer]

Considered these but discounted on bolt size and bush too big

http://www.pumaspeed.co.uk/product-Powerflex-PumaFiesta-Mk4-5-Front-Wishbone-Lower-Rear-Bush-set_196.jsp

[chrisgixer]

This type pop out going by entries on some forums
http://www.ebay.co.uk/itm/Powerflex-Bush-Poly-Audi-S3-Mk1-Typ-8L-4WD-Front-Wishbone-Rear-Bush-/380663446274

[chrisgixer]

Too big?

http://youtu.be/_O3bRw-OUZI

[chrisgixer]

Close. If they don't pop out or break the wishbone.

http://www.ebay.co.uk/itm/Ford-Puma-Front-Wishbone-Anti-Roll-Bar-Bushes-Rear-Beam-Mounts-Poly-/370607560265