Poly Suspension Bushings - (15 Year Review)

I have been using Polyurethane Suspension Bushings for 15 years in my 3800 Supercharged Pontiac Fiero and have learned the good and bad side of living with these over the long term. These same lessons could be applied to the C5 Corvette when considering upgrading the stock rubber to poly bushings. Here is my 15 year review & who I think might benefit most from using them.
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[eddiemcmurray]

I'm a taxi driver in The UK and would drive up to 50, 000 miles per year. I thought poly bushes were The best thing ever for a number of year's as I would get at the least twice as much life out of the poly bushes that would from the rubber bushes. Until I started to notice that the metal that was in close contact with the bushes was wearing away. The wishbone arms would lose there tightness at holding the bushes to the point that the arms would need replaced so they could properly hold the bushes again. Another thing was the pins and sleeves and would wear and occasionally seize making it very difficult to get the arm apart again. I went back to using the OEM-quality rubber bushes and never had to replace an arm again. Just like to pass on my experiences when using poly bushes at high milage.

[Schrimpieman]

This is the most realistic, non-bias, &informative vid I've seen on a long time. Most just brag about how new and great everything is, but long-term operation is more important than the initial "wow" factor.
Thanks for sharing !!

[frankpeutz]

Try to wrap a single layer of teflon tape around the inner (steel) bush thereafter smear a little silicone grease and you will reduce maintenance drastically (5 years or longer, you’ll see).

[pavlos]

This convinced me to go with simple rubber for the daily driver. Thanks for saving me a lot of grief.

[sst]

Thank you for the video. I always consider buying these for better handling/performance, but with daily driver going to pass seeing the maintenance. Extremely appreciate your time. I will save a check.

[Friedbrain]

I was going to buy polyurethane bushing with about 10% more stiffness, but they also had the benefit of grease fittings and used red bearing grease. Those would be the best of both worlds I think unless you really want to race on twisty roads all the time.

[vice]

Nice video, Kenneth.
People, keep in mind that your current Fiero's rubber bushing are probably at least 15 to 35 years old. So, it's not firm like it used to be. So, replace it with new rubber bushings & you'd be surprised how firm they are.
I see too often people switch to poly, thinking rubber bushings are terrible but they forgot to consider the fact that their rubber bushings are OLD.
Most of us probably will never use the track for racing full time or try the track few times doesn't mean you should switch to poly. Nope!

[pmodd]

Good video, covers the issues with poly bushes nicely. I always avoided them for moving arms and favored press-in vulcanised rubber bushes. After going from a full set of rose-jointed arms to HardRace vulcanised rubber bushes (Nissan 180sx), the handling wasn't quite as crisp with the rubber, but it was decent. Meanwhile, NVH was massively improved. I found the same thing changing from poly rear subframe mounts to nismo vulcanised rubber bushes; no noticeable performance difference but my word the NVH was better with the hardened rubber.

The biggest trap imo are polyurethane gearbox bushes for a RWD. The clutch kicks with the poly bush were great, there was no mechanical binding and the gear shift/release didn't stick, but I hated the noise the bush pumped into the cabin so much that I put a stock one back on 2 hours after installation at 10pm. Replaced the factory rubber bush with the Nismo hardened rubber version and it was 80% of the poly bush in terms of performance and only a minor increase in NVH.

Personally, I don't think poly is worth it at all, unless it's a dedicated track car and you don't want to keep replacing heim joints. The main reason I think rubber gets ignored for performance is that people don't pay the extra for hardened versions, then they torque the arms with the car on stands. Rubber bushes won't function properly if they aren't torqued at static ride height, as deflection is a component of their function (i.e. internal deflection is what allows their rotation).

[dscary]

Wrap Teflon tape around the Bushing and metal sleeve along with that clear sticky grease and you shouldn't have squeaky bushings again EVER!!!

[williamdejeffrio]

Wow - thanks for sharing that. Wasn't aware of the increased need for maintenance.

[kurdtpatton]

This was super helpful! Thank you so much for concise and thorough explanation.

[patrickjohnson]

That's what I want to do this weekend relube my bushings.

[venskus]

youre a godsend im over here trying to choose betweem replacing my bushings or just getting new control arms all around. this easily just put me over the edge and im just getting new arms all around to avoid instllation hassle.

[YanDaOne_QC]

I filled the stock rubber lower torque mount of my Sentra 2.5 ser spec V with Lepage® Polyurethane construction adhesive in hope of getting it last for more than a year or two (after 3 replacements). It ended up adding a bit of stiffness. 4 years since I did it and the mount is still fine. Total cost: 5$. I'm about to replace the rear axle beam and will probably do the same with thoses bushings, just to try it.

[BCole-bjlv]

I just happened to see another video by a British fellow tell how he tightly wraps his sleeve with overlapping wraps of teflon tape plus the bushing itself and the ends. He said he never gets squeaks this way. He smears a little of that grease on first, wraps it, then adds more lube and installs.

[tracewallace]

I suppose I'll be there one to say it, 🙄
Damn nice vice you got there boss 💪🏻🇺🇸😎

[j_moonchild]

Old video, I know, but one thing i like to add. Some polyurethane bushing manufacturers have different choices of hardness to choose. Usually three from soft to hard on Durometer Hardness Scale A, or ShA for short. Scaling from 0 to 100, where 100 is hardest. For example:

Light car, street use - pick a soft bushings. 75 ShA
Heavier car, street use - pick mediums. 85 ShA
Heavier car with occasional track day use - hard bushings. 90ShA
Light car for track or race, pick medium or hard bushings. 85-90ShA.
Usually I choose 75ShA bushing, because they give me the best compromise between stock rubber and polyurethane.

By the way. I don't know what grease came with PowerFlex polyurethane bushings, but they don't squeak even after 8 years after installing them. Or they use some engineering magic to eliminate squeaking? Also, it depends what car you have. For example BMW e46 has so comfortable ride quality with stock bushings, i replaced all of them with Power Flex and they didn't make the car harsh and don't let too much road feedback to the wheel. And the car is still pretty quiet. But, never put polyurethane to gearbox or engine mounts, it ruins the quality of almost vibration free engine and gear knob. On the other hand, very lightweight Mazda MX-3 will go full "race-mode" when changing the bushings to polyurethane, or you have to find a manufacturer who make very soft ones for you.

[rooh]

I went with the prothane entire suspension poly bushings kit for my SRT-4, and I've been incredibly happy with it, had them in for about 18 months now.

[psychkosys]

I replaced my dog bone with Rodney's solid mount bone. I drive a 2.5 so...you want to talk about vibrations! I replaced the trans mounts, sway bar, end links and control arms with red poly. She rattles like crazy but i love it

[videomaniac]

I upgraded the stock anti roll bars on my 370Z with some stiffer Hotchkis sways that have polyurethane bushings. The U shackles for the bushings have zerk grease fittings and so I just shoot some polyurethane grease into them every other oil change, no squeaks after two years.