This project has failed.. read the below replies for more info..

The rubber bushing in one of my rear control arm's broke, so i decided to rebuild the entire thing out of 3M urethane (Window Weld). My 1st advice is to wear gloves, if this stuff gets on your hand, it's going to stay there for a while! (Speaking from experience here)

The thumb on one of my disposable gloves had stuck to the urethane and ripped, getting the stuff all over my finger.. Kerosene, gas and Gojo hand cleaner all failed to get it off..  

A next thing is you need to make a mold and clamp system to hold everything accurately in place while it cures.. I used wire to tie down the control arm and also bolted the center pin to my mdf mold to keep everything in place..

To get out the old bushing, i used a hammer to knock out the center pin and a hack saw to cut up the old rubber bushing..


A little heat was added via a propane torch..


and the old bushing came out pretty easy..




A drill and wire wheel cleaned up the surfaces pretty well..


Custom mold was made out of mdf. The center pin was properly positioned to be exactly as stock and bolted in place.


The control arm was set in place and carefully packed to encure there was no air pockets..


It's not the neatest job (i got a bad tube of urethane and had to make the best of it) but hopefully should provide me with some good service.. To add, the tube of urethane cost me $11 vs a new arm from the dealership at $105..



All i need now is some good sun for it to cure and i should have that sucker back up for some durability testing.. Will update on how well it holds out..

I think i posted this in the wrong forum, could someone please move it if necessary please..

I hate to be a constant naysayer - but - there are different hardnesses of urethane, and window weld is typically a lot softer than would normally be used for suspension bushings.

Have you ever worked with "factory made" urethane bushings, let's say the type of stuff that Prothane or Energy Suspensions makes?  It's more like plastic than it is rubber.

Using polyurethane bushings on an off road vehicle is something that needs to be approached with caution - the general idea behind poly bushings is to limit suspension flex (which promotes better handling and road holding), which is the exact opposite of what you're trying to achieve with the Calmini lift kit etc.

^ All ideas are always welcomed..

I have used energy suspension bushing already, so i have an idea on their stiffness.. This is my 1st time trying the 3M window weld, so i'll have to wait until it dries to get a good idea on how stiff / soft it is..

I was thinking that since the Calmini kit allows for alot more flex in the rear, it will place extra stress on the factory rubber bushings and cause them to wear our faster..

Now, if the window weld is flexible enough, shouldn't it theoretically work like a stock rubber bushing, but last like an aftermarket poly bushing?

Also, will stiff bushings actually limit suspension flex? I thought that was mainly down to the length of the dampers and spring rates...

I'm now getting a good luck at the pictures you posted - for some reason they wouldn't open completely when I first read the post.  I was puzzled earlier by your reference to a "center pin" - there is no center pin perse, but rather a sleeve, through which a bolt passes - I get the impression that in your case the sleeve and bolt have "bonded" due to corrosion - this will probably cause the bolt/sleeve to tear out of the window weld, making it a very short lived repair.

Think about this - in an "on-road" situation, lateral movement of the body relative to the suspension will occur primarily in a turn due to weight transfer.  The weight shifts off of the inside wheels (the body lifts) and onto the outside wheels (the body settles), and we look for ways to limit this effect, such as anti-roll or anti-sway bars.

In an "off-road" situation, there is less body movement due to weight transfer, but there is a greater need for long suspension travel.  As you drive through a trail you want the wheel to follow the terrain rather than limit the motion in any way - one wheel goes over a hole or low spot, you want that wheel to travel downwards as far as possible, staying in contact with the surface and transmitting drive, if the wheel goes over a hump, you want it to travel up, rather than lifting the body, and the remaining wheels causing them to lose contact with the surface - the exact opposite of what's needed "on-road".

Incidentally - I take it you're aware that some some folks disconnect and/or remove the anti-sway bar when off-roading, to prevent it from limiting suspension travel, which by the way, I do NOT recommend on a daily driver, that sees only occasional off-road use - I mention this to further emphasize the perhaps diametrically opposed nature of suspension tuning for "on-road" & "off-road" use.

Rubber suspension bushings are usually bonded to an inner sleeve and if circular will typically also be bonded to an outer shell - in this case the link rod.  These sleeves are usually tightly secured so that the suspension deflection comes from the flex in the rubber - traditional polyurethane suspension bushings do not function in this way, they are engineered to have a minimum of flex, and they allow suspension motion by allowing the center pin to rotate as if it were in a bearing - this is why poly bushings must be installed with a special grease.

Will stiff bushings limit flex?  That would depend on your interpretation of the term flex - they limit deflection and if the desired suspension motion depends on that deflection, as would be the case for lateral movement in a five link design like the back of a first gen GV, then there will probably be some reduction in suspension travel.

I couldn't find the correct term, but when i said center pin (which i knew was wrong) i really meant the sleeve.. My sleeve and pin is actually in good condition with no rust / corrosion to speak of. I just used the bolt to hold the sleeve down to my mdf mold so it would not move around.

Rubber suspension bushings are usually bonded to an inner sleeve and if circular will typically also be bonded to an outer shell - in this case the link rod.  These sleeves are usually tightly secured so that the suspension deflection comes from the flex in the rubber - traditional polyurethane suspension bushings do not function in this way, they are engineered to have a minimum of flex, and they allow suspension motion by allowing the center pin to rotate as if it were in a bearing - this is why poly bushings must be installed with a special grease.

I just came back from under my GV and was taking a 2nd look at the factory suspension components.. I agree that the inner sleeves are tightly secured to the vehicle when mounted, but i still believe that some movement must come from the sleeve rotating about the center bolt..

If all the flex were to come from just the rubber bushings, and judging from the way they are designed, i can see that they will never last long with the increased flexibility from the Calmini kit and would thus appear to be a weak spot in the new system..



If you look closely at the factory rubber bushing design, you can see that the factory bushing is designed to flex a very minute amount in the horizontal plane (left to right) but not much in the vertical plane (up / down) because of the solid design (by the arrows).

When i get time, i will only connect 1/2 of the trailing arm and manually rotate it up and down to see exactly where 'flex' or movement occurs..


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If you look closely at the pic, you will see where the rubber is beginning to crack around the center sleeve..

I think i am going to take down all 5 rods and put some grease between the inner sleeve and the mounting surface on the vehicle to help allow for better rotation..

What do you think?

some movement must come from the sleeve rotating about the center bolt..

Nope, the bolt squeezes the sleeve between the bracket they're bolted into.  If not then the bolt's not tight enough and will make a heck of a noise. The only movement is in the rubber.  That' s actually what the little holes and arrows in the rubber are for, proper orientation for up/down and side/side flex.

The window weld did not work.. It's definitely too soft and the inner sleeve let go as soon as i put some force to it..

I was now looking at the Calmini replacement arms



and judging by how those bushings are designed, the arm is free to rotate without any need for bushing flex.. I wonder if it is possible to convert the factory arm to something like the Calmini design..

Do Calmini do both upper & lower links?  I only see the lower ones on their site.

They state that they use reverse cut polyurethane hourglass bushings that allow more deflection and twist than the stock bushings - presumably this means that the inner surface of the bush is tapered and only makes contact with the sleeve at the outer edges.  It will allow more articulation but how well will it locate the axle in the long term?

When you ask about converting the factory link are you referring to making it adjustable or to the reverse hourglass bushings?

Theoretically making them adjustable should not be difficult - find a suitable sized turnbuckle and a machine shop that can cut both right & left hand threads and cut the link and thread it to take the turnbuckle - mind you, making them adjustable and safe is a different question, now you have to start considering the type of metal, etc.

The reverse hourglass bushings might actually be easier - a custom mould and the right shore (hardness) polyurethane - you'd have to do two piece bushings for each end because of the taper.

Why not just order a set of OEM links - try SouthWest Suzuki - compare their prices to LifeStyle Motors, they might well be cheaper.  LifeStyle has to source spares through Simpson Motors in Barbados, and for parts that are not being shipped directly from Japan, you'll end up paying duty & VAT in Barbados and then again in Trinidad - I've been able to source parts from SouthWest for less than half of what Simpsons quoted.

Just so you're aware - the Calmini links are not designed to add flex but rather adjustability - to correct a pinion angle problem created when you lift the vehicle.  As the vehicle goes up the four trailing links tip the rear axle nose upwards and the end result is that the rear drive shaft UJ angles are no longer equal and the end result is vibration - extending the lower link is the fix (or shortening the upper link, but that has less desireable side effects as the suspension moves).  My suspicion is that reverse hourglass bushing was created as a solution to the reduced flexibility of the more traditional cylindrical polyurethane bushings that I had raised earlier.

As far as i know, Calmini just have the lower links..

I was referring to converting the just the bushing to copy the Calmini design.. but it sounds like more trouble than it's worth, assuming i could find the harder polyurethane and build it right..

The upper control arm from Southwest Suzuki is $71 US, but by the time i add in shipping / customs & VAT, it will come up to more than Lifestyle motors.. so in this case, i'll have to buy local..

Thanks for the info on Pinion angle, learnt something new there.. Do you think it's advisable for longterm reliability to get the adjustable Calmini arms, even though it is not really recommended for the LWB vehicles..

I tend to agree on custom made bushings in single vehicle quantities being more trouble than they're worth, especially since in my case it means tracking down and importing the right hardness polyurethane - what I can tell you is that modifying off the shelf poly bushings probably will not work - you can cut them, but it must be done with a very sharp blade - and machining (lathe, etc.) type stuff is a no-no - it destroys the surface of the polyurethane which then disintegrates quite rapidly.

With regard to the adjustable arms on a LWB vehicle, it's probably not necessary - because of the link lengths involved, a two inch lift (just as an example) on a SWB vehicle will cause a greater change in the pinion angle than the same two inch lift on a LWB vehicle.

One option, if you have a welder, would be to pick up a Johnny Joint and a bung.  Cut your existing tube, put the correct size and thread bung in, then the Johnny Joint and your done.

I think someone else did similar, I would have to hunt through the threads to find it though.

One option, if you have a welder, would be to pick up a Johnny Joint and a bung.  Cut your existing tube, put the correct size and thread bung in, then the Johnny Joint and your done.

I think someone else did similar, I would have to hunt through the threads to find it though.

Interesting! A urethane bushed ball joint..

http://www.currieenterprises.com/cestore/johnnyjoints.aspx

I was watching the video on that website and saw the joint can rotate in both the horizontal and vertical plane.. would that work good in the Grand Vitara suspension or could it cause alignment problems?

the prices seem pretty reasonable for what you are getting..

http://www.zukiworld.com/forum/build-diaries-how-to-diy/sj-410-rear-4-link-build/

found some great info here.. will look further into the Johnny Joints.. thanks for the info!

I recognize that thread. 

What you want to make sure of is that the width where the joint replaced the existing bushing is the same.  Otherwise you will need to use a washer or a similar device to act as a shim to make up the difference.  If you do it right you will have the same length as before, just with a beefy new joint.

The rig you want to look at for whitfield's Tracker.  I'm pretty sure his is the one where I saw the modifications done to the stock arms to lengthen them a bit, as it's the only reference I can find on the site.  But almost all his pictures are dead.