A Arm Bushing

[E Sully]

I am going to replace the front suspension bushings on my 1973 911T with the Neatrix bushings. The directions say to scribe the arm at the existing angle to set the angle of the brackets. Both left and right rear brackets on mine are 30 degrees. The front bracket on the right arm is 32, and the left is 37 degrees. I am curious what angle others have used for their replacements. Thanks for any help.

[steely]

Rears 20, Fronts 34.

[E Sully]

Thanks for the info.

[steely]

I admitted to having fretted over these - used one of those magnetic level from sears. Was glad L&R were the same and I was interested in the "real" numbers. I saw some references here, and I think think the nicer bushings furnish recommended numbers, but mine went back on (A Arms back onto the undercarriage) the frame easily enough. I don't know how much preloading if any was involved. I think when they are very loose, the holes lends them selves to some angle slop that gets eliminated when you tighten down.

[E Sully]

I read the directions for the more expensive ones and they were 15 and 19. Mine measured about twice that when I removed them. I know the two bushings are manufactured differently. I just wondered what the factory used, since this seems to be what Neatrix wants to duplicate.

[hcoles]

Is the intention to have the bushings relaxed when installed at the wanted ride height or are they wanting to split between bushing windup comparing full compression and rebound? These could be different or the same.

[moneymanager]

I think a degree or two here is irrelevant. The bolts will pull everything into position when you reinstall the A arms and the rubber will accommodate.

[hcoles]

agreed, but I curious re. the intent then for different cars the target is known

[Flieger]

Since rubber bushings act just like another torsion bar the intent should be to set the bushing to be relaxed at full droop/extension. To be "safe" I would overshoot this by a few degrees, then adjust the torsion bar accordingly to set ride height.

[hcoles]

maybe what you are saying is the bushings will slip around to "find" a position of least maximum rotation stress in both directions.. good thought, if yes then as you say the bushing install angle is not that critical

[Flieger]

Are Neatrix hard plastic or rubbery? If hard plastic, then the angle is irrelevant. They do not act like a torsion bar, just a simple bushing.

[Bill Verburg]

Originally Posted by Flieger

Since rubber bushings act just like another torsion bar the intent should be to set the bushing to be relaxed at full droop/extension. To be "safe" I would overshoot this by a few degrees, then adjust the torsion bar accordingly to set ride height.

rubber bushes do act like a torsion bar and need to be set where the relaxed position is at the ride height, even though they act in torsion they are not designed to substitute for or in addition to a t-bar . You want the minimal amount of twist in the rubber as the suspension moves through it's range in both directions

[hcoles]

thx Bill, I would hope the material, whatever it is, can flex enough to not cause "slippage" only flex during operation, this was probably part of the original design.

[Bill Verburg]

Originally Posted by hcoles

thx Bill, I would hope the material, whatever it is, can flex enough to not cause "slippage" only flex during operation, this was probably part of the original design.

It is, rubber bushes twist w/ a fixed outer race

plastic bushes have fixed outer races w/ steel rotating in the inner race.

spherical have fixed outer races w/ teflon sliding inner races

[pete3799]

Originally Posted by Bill Verburg

rubber bushes do act like a torsion bar and need to be set where the relaxed position is at the ride height, even though they act in torsion they are not designed to substitute for or in addition to a t-bar . You want the minimal amount of twist in the rubber as the suspension moves through it's range in both directions

So should the angle be measured before dis-assembly with the weight of the car on them. Just curious as i'll be doing mine this winter.

[hcoles]

that seems like a good idea, Elephant has instructions online including the install angles, so it might be an idea to compare numbers

[E Sully]

The Neatrix bushings are very similar in size and feel to the original rubber. Elephant recommends 15 and 19 degrees. As I stated earlier, my stock bushings were 30 and (32,37). They are the original bushings. I was wondering if anyone has an A arm with stock bushings off the car that they could measure the angles to compare.
In the photo the Neatrix is in the center of the two stock bushings.

[E Sully]

Just a quick bump to see if anyone has any new input on the angles.

[redridge]

I wouldnt sweat it to much... if you install it while it is still wet from the liquid soap, it will fall into its relaxed state.

[ivangene]

yea, I agree with Ferd....in fact I never even looked at the "angle" of the fronts as it is a rotational fit (although I didn't use rubber replacements....)

I will mopst likely be replacing mine again with something other than the Weltmiester ploy-graphite crap! (read: squeak squeak)