Log in

View Full Version : potential grease compatibility prob. w/polyurethane control arm bushings



Grubester
09-09-2024, 07:19 PM
***This is a duplicate post -- please comment on the other one that starts with: "Yikes!" -Thanks... "the poster" ***

The FFR Assy. Man. mentions urethane bushings for the mounts for the differential on IRS units, but are the bushings that come preinstalled in the control arms also urethane?
This is a big deal because after talking with Lucas Oil (they make the petroleum-based grease I used: Red 'n Tacky) they said it is not compatible with urethane materials.
Further, I spoke with a tech guy at Thorbros, (Francisco, IN) and he said that petroleum grease degrades urethane over time. Thorbros makes urethane bushing assemblies.

(when I asked Thorbros about design criteria regarding length of sleeve inside the bushing assemblies, he said their design rule is that the sleeve is 0.005" to 0.010" shorter than the stacked length of the two bushings. This gives a light-crush on the bushing assembly once the bolts are fully torqued [I'm pre-greasing, following w/grease gun]. I asked because when I get anywhere near the torque value on the IRS upper control arms they are effective locked up: there are several remediation paths possible, but that's a different post.)

Anyway, I may need to disassemble front and rear suspension and clean/re-grease the bushings... we'll see.

Factory Five Racing:
1) please comment on the material type used for control arm bushings,
2) please comment on grease-compatibility issues I've mentioned,
3) page 16 of "Req'd Supp." doesn't mention anything about grease type

Thanks all!

cv2065
09-09-2024, 08:06 PM
I used green synthetic grease. It’s compatible with just about everything. The joints should be a little tight at first but will loosen up once the grease is circulated around. Just make sure you pre grease and don’t grease after you torque the joint as it will deform the bushing.

Jeff Kleiner
09-10-2024, 07:37 AM
I recently changed all of my poly bushings to spherical bearings. They had been lubed regularly for 17 years and 30k miles with regular petroleum grease and looked new when I pulled them out.

Jeff

Grubester
09-10-2024, 09:32 AM
Sorry for duplicate post -- please comment on the other one that begins with "Yikes!"

When I first posted, it looked like the first one had not gone through. Sorry... and Thanks!