Greasable pivot shafts / polygraphite bushings

[AJReigart]

I am rebuilding factory LCA with sway bar tabs for a street performance 66 Dodge Coronet.

I will be stiffening the LCA's with plates and installing a 1 1/8" sway bar, installing heavier torsion bars (either .96 or 1.03), and using urethane bushings most elsewhere.

My planning assumption is that front-end weight will around 1800 to 2000 lb (50:50;F:R).

My questions -

(1) what are people's experience with greasable pivot shafts / polygraphite bushings? I've heard these pivot shafts have been known to walk ..... (hearsay).

(2) with all the stiffening/tightening up of the front suspension I am doing (compliance), would rubber be a better choice in the LCA to 'soften' the feel?

 

[AR67GTX]

Poly bushings don't do well in the lower control arm due to the off-axis movement resulting from the torsion bars as the arms rotate up and down. It's a similar situation to mid-year Corvette rear trailing arms that have to twist slightly as the cycle up and down. Poly bushings do well to last a year or two in them. It just tears them apart and they crumble. Upper a-arms is probably OK for poly.

 

[PST]

We have seen now issue with crumbling or deteriorating polygraphite bushings. When used with the greasable pivot. The end of the shaft that goes into the control arm is oversized so it eliminates the use of the inner sleeves. On the oem set up (rubber bushing) the bushing is not designed to retain or hold the the pivot shaft in place. It is held in part by the strut rod being attached to the control arm and the torsion bar. The idea behind greasable pivot shaft is to allow the arm free movement to move up and down as quick as possible in and out of turns/cornering to keep the tire planted. The ride will be stiffer than rubber due to the durometer rating difference between polygraphite and rubber, but will give you a more modern ride. We have sold 851 sets of greasable pivot shaft with no issue pertain to the bushings coming apart.

Thanks
James From

 

[AJReigart]

We have seen now issue with crumbling or deteriorating polygraphite bushings. When used with the greasable pivot. The end of the shaft that goes into the control arm is oversized so it eliminates the use of the inner sleeves. On the oem set up (rubber bushing) the bushing is not designed to retain or hold the the pivot shaft in place. It is held in part by the strut rod being attached to the control arm and the torsion bar. The idea behind greasable pivot shaft is to allow the arm free movement to move up and down as quick as possible in and out of turns/cornering to keep the tire planted. The ride will be stiffer than rubber due to the durometer rating difference between polygraphite and rubber, but will give you a more modern ride. We have sold 851 sets of greasable pivot shaft with no issue pertain to the bushings coming apart.

Thanks
James From

Thanks James.

Question : There also seems to be confusion as to whether a solid (non-greasable) pivot shaft with inner sleeve can be utilized with a polygraphite bushing. My assumption is the diameter of the greasable pivot shaft is (at least) that of the OD of the OEM shaft/sleeve.

Can/should the OEM pivot shaft be utilized?

Thoughts / comments?

Best Regards,
Al

 

[PST]

If you are using a stock oem pivot shaft and would like to use a poly lower control arm bushing. You will need to reuse the inner sleeve. The greasable pivot shafts that we offer are over-sized on the OD to the same size as a non greasable shaft with the inner sleeve already installed.

Thanks
James

 

[AJReigart]

If you are using a stock oem pivot shaft and would like to use a poly lower control arm bushing. You will need to reuse the inner sleeve. The greasable pivot shafts that we offer are over-sized on the OD to the same size as a non greasable shaft with the inner sleeve already installed.

Thanks
James

Thanks Jim. Is this an acceptable/recommended alternative installation practice with your outer shell / poly bushing supplied in the rebuild kit?

I've read and/or been told this (solid pivot shaft with poly bushing) is the recommended practice/install method (by poly bushing and/or other suspension component suppliers).

Any thoughts or functional/performance issues?

I assume the bushing/shaft would eventually get noisy (squeak).

Also, I'm also looking at your adjustable strut rods. Read in another FBBO post where PST was looking into poly bushing at the K-frame end as an alternative. Any status update there?

 

[PST]

Yes it is an acceptable practice. As for the adjustable strut rods we are still only supplying that with the solid mounts.