Rubber vs Poly bushings

[Scotsman]

Regarding rubber vs poly bushings. I have heard the poly bushings can still give a significantly harsher ride.
What are the downsides of rubber other than durability. AND how long should you expect rubber bushings to last, recognizing that this will be a weekend driver.
I have read posts saying the rubber bushings have been improved with greater durability . Is this true

 

[TR4A_IRS]

Welcome to the forum. If you haven't already, I recommend you do a search on this topic on the forum. You will likely find all the opinions you can stomach. ;-)

Your next question should be about oil and ZDDP!

FWIW, I like poly.

 

[TR3driver]

I have read posts saying the rubber bushings have been improved with greater durability . Is this true

Could be, I don't know. But the rubber sealing rings I bought and installed just a couple of years ago are literally falling off the car. I found one laying in the street the other day!

My opinion, tires (and springs) make a much bigger difference to ride quality than the bushings do. I didn't notice any real increase in harshness when I converted from rubber to Nylatron (which is firmer than the hardest poly). Before that, I was replacing the rubber every year or two.

I had the chance to change my mind when I built my current TR3 from the wreck of my previous TR3A. Instead I kept the Nylatron. One less thing to go wrong.

Some have reported that poly can develop an annoying squeak when it gets dry. A generous smear of silicone grease should keep that from happening for a long time, though.

 

[70herald]

Your next question should be about oil and ZDDP!

:lol:

There are different "grades" of poly. I have several "blue" bushings on my car which are about the same level of hardness as the rubber. There are other grades which are harder and much harder. On the front control arms I have a different type and they are HARD, and the roughness is noticeable.

The rubber breaks down do to age, contamination etc... how much you drive affects the lifespan but it is not the only issue.

 

[KVH]

My new rubber bushings failed quickly after being installed. It was a long, careful front end rebuild, and party redone just to get those twisted, cracked "new" rubber bushings back out.

I wouldn't use the standard rubber bushings. I now have poly and my ride is quiet and smooth. For a Triumph.

 

[TR4A_IRS]

I have read posts saying the rubber bushings have been improved with greater durability . Is this true

Could be, I don't know. But the rubber sealing rings I bought and installed just a couple of years ago are literally falling off the car. I found one laying in the street the other day!

My opinion, tires (and springs) make a much bigger difference to ride quality than the bushings do. I didn't notice any real increase in harshness when I converted from rubber to Nylatron (which is firmer than the hardest poly). Before that, I was replacing the rubber every year or two.

I had the chance to change my mind when I built my current TR3 from the wreck of my previous TR3A. Instead I kept the Nylatron. One less thing to go wrong.

Some have reported that poly can develop an annoying squeak when it gets dry. A generous smear of silicone grease should keep that from happening for a long time, though.

Agreed about the possibility of squeaking. The poly sway bar bushings on my daily driver (a BMW) emit a healthy groan.

 

[Member 10617]

The rubber bushings on my front suspension lasted less than one year before they began to fall apart. I had them replaced with poly and all looks fine two years out. I can't say if the ride has become harsher.. and I don't detect any squeeks. Just for good measure, however, I'll apply some silicon grease, as Randall suggests.

 

[tdskip]

I'd never install rubber bushings on one of our cars at this point. The "harshness" concerns are overblown in my experience, while the handling and control improvements are quite real. Good lube on the bushings, which comes with them, will take care of most if not all of the squeaking.

 

[Geo Hahn]

I used poly on my TR3A -- if it makes the ride harsher on a '3' then it would merely be taking it from 'very harsh' up to 'extremely harsh' - IOW, not really noticeable.

Oddly, my TR4 has the orginal 48-year-old rubber bushings and they are fine.

Do the Brits keep the formula for rubber a State secret? They certainly knew how to make them.

 

[glemon]

I have never noticed an appreciably harder ride on the cars I have used poly bushings on, including my current TR250. Funny the squeak should be mentioned, I drove my car Sunday and noticed a squeak going over some speed bumps, I went in and put some silicone grease on the poly bushings in my front sway bar (I think I originally greased the suspension bushings, but not the sway bar), anyway it is much quieter now.

As far as longevity the lower inner front suspension bushings on most of the British cars I have owned seem to last forever in rubber, which is god because they usually have a metal insert that rusts to the bolt permanently. Other bushing seem to have much more variable lifespans, and I have had some lengevity issues with new rubber bushings too, especially upper inners on 4A-6 frt suspension.