Spherical Bearings 1/4/18

This is a race car.  So, of course, I’m always looking for faster lap times.   Making the car handle better is one of the best ways to do this.

When I built the car, I considered many options for the suspension bushings – rubber, poly, and Delrin.  At the time, there were no good options for rod ends and spherical bearings.  On the advice of the good folks at Flyin’ Miata, I used rubber bushings with a higher durometer rating than stock.  That was the hot ticket.

To be honest, I was never really happy with those.  They just didn’t move as well as I wanted them to.  They required a lot of force to move them around.  From previous experience, I knew that was a bad thing.  I wanted the suspension to move freely, without transmitting movement to the frame and body.

I considered a lot of options, and settled on a set of bushings from    Miata Roadsters .  Now, this is not a cheap option, at $1,535.  +$100 to have them drop shipped from Japan.   But if it got me what I wanted, I figured it was worth it.

This is a well designed kit.  The spherical bearings are in a pillow block set up.  And they are sealed with a rubber dust seal.   There is no provision for greasing them, though.  We’ll see how that works out.   If you’ve worked on Miata bushings, you know that they are not all the same size.   These are all well marked for location.  Don’t get them mixed up!

Well packaged and labeled for location
Good documentation, too.
Pillow block Assembly, ready to install.

 

 

 

 

 

Different widths for different locations.

Installing these into the stock suspension components requires a fair amount of force.  You cannot do this job without a press.  Don’t even consider doing this with a vice or a C-clamp like you can with rubber bushings.  You NEED a press.  Fortunately, a cheap Harbor Freight 12 ton press will do just fine.

Harbor Freight 12 ton press works fine.

Also, do not plan on sending all the bushings and parts to a machine shop and having them pressed in, bringing them home, and installing them.  They will need some fine adjustments during installation.  The bushings will need to be moved a little bit here and there to fit right.

I used sockets of various sizes to support the pieces and press in the bushings.   You just have to be a bit imaginative to get everything set up the way you want it.

Two areas that need extreme caution.   The front lower arms do not fit around the

You can easily bend the arm.

base of my press.   It would seem obvious that you just put the whole arm in to the press.   If you do that, you’ll bend the arm.   I didn’t plan on re-using the arm, so I did it anyway, just to show what would happen.  It’s not good.  You can see that this arm is ruined.

 

The same issue occurs with the rear lower arm.  I planned to use that one, so I needed a better plan.  I welded a piece of angle iron across the ends for stability.  Then Pressed in the new bushings.   After that it was easy to cut off the steel and repaint the arm.  Although, I could have left the angle iron in place, there was enough room, and it might have added some strength.

Temporary support welded on.

 

Bushings safely pressed into place.

 

 

 

 

 

You would think that all of the bushings would be centered in their respective spaces.  But, that’s not the case.  Some are, and some are not.   That is why you need a press handy, to make those fine adjustments.

Centered. But the spindle bushing was later moved off center.

 

Offset to fit the chassis.

 

 

 

 

 

Once all the bushings are in place, it’s a “simple” matter of assembly.   Put everything back together the same way they came apart.   You’ll need to set ride height, corner weights, and do an alignment.

There is a very small amount of resistance to movement from the rubber dust seals.  But it’s very small.  Gently finger pressure moves the arms up and down.   There is no bind at all now.   I haven’t had a chance to drive the car yet, but I think it’s going to be a whole different experience this year.   🙂