Polyurethane vs. Rubber - PeachParts Mercedes-Benz Forum

lsmalley · #1 11-14-2013, 11:32 PM

Thinking of replacing my rubber bushings with polyurethane. What do you guys think? Pros and cons?

TnBob · #2 11-14-2013, 11:48 PM

Bad idea. Done right, polyurethane will last about 5 times as long.

What would you do with all that free time ?

pawoSD · #3 11-15-2013, 08:30 AM

Do they make Polyurethane bushings for the W126?

DieselPaul · #4 11-15-2013, 08:35 AM

Who makes poly bushings for a 201/124? I've looked and ever found any. We used to run poly everything in Fieros.

lsmalley · #5 11-15-2013, 10:27 AM

Quote:

Originally Posted by DieselPaul

Who makes poly bushings for a 201/124? I've looked and ever found any. We used to run poly everything in Fieros.

What was your experience with using the polyurethane components?

DieselPaul · #6 11-15-2013, 11:05 AM

If you don't use the proper grease they squeak like hell.

Otherwise they do improve the handling of the car but a lot of that is probably from simply replacing worn out bushings. I've never, and I doubt few have, put poly bushings in a brand new car. Usually we are putting poly into cars with 100,000 miles on them and are blown away at the improvements.

On some worn out cars you could probably put URO bushings on it and be blown away by the improvement for a few days.

How much are the bushings? There was a Malaysian guy I think selling poly bushing kits for just over $1,000. To me that's not worth it. On fieros poly bushings are the same price or cheaper, so upgrading was a no brainer. But the difference between your car and a DTM car is not the bushings, so don't expect to smoke M3s in the twisties with bushings alone.

lsmalley · #7 11-15-2013, 11:17 AM

I will definitely not be dropping $1000 for bushings. This is just more for an upgrade to torn boots and high stress parts like transmission mount, strut/shock mounts, and sway bars. I have noticed that the boots on my tie rods are showing small tears and my ball joint was just replaced, but I'm thinking of taking off the rubber boot and putting on a poly boot.

DieselPaul · #8 11-15-2013, 03:54 PM

Poly joint boots suck. At least on fieros they don't hold grease very well. Poly is harder and less pliable which is why it is nice for handling in bushings but for boots it doesn't move well with the joint and let's grease out and crap in. Mercedes themselves sells just boot kits.

Can you provide links to what you're thinking about buying? I've never seen off the shelf Mercedes parts like what you're talking about.

lsmalley · #9 11-15-2013, 04:42 PM

a picture of the polyurethane ball joint boot. It fits nicely. and once its installed it will compress as seen in the other photo to create a nice seal

BillGrissom · #10 11-15-2013, 10:03 PM

I use polyurethane dust covers on all my ball joints and tie rods. I just put one on a lower ball joint on my 300D, after forcing grease in. It looked OK, with <10 mil play, just dry grease and slight surface rust. I found the right-side ball joint too worn, with no boot left, nor grease. Why I am on here searching. I do have a shop press, once I get the part. If a cheap rubber boot, I will install a poly one. I had a bag of Energy Suspension 5.13102R dust covers for my old Chryslers that fit well.

TwentyFiveSixteen · #11 11-15-2013, 10:40 PM

Quote:

Originally Posted by DieselPaul

Who makes poly bushings for a 201/124? I've looked and ever found any. We used to run poly everything in Fieros.

I have bought them from Ake at Hedgehog Motorsport in Thailand. You can choose your hardness (street/race) and he'll ship them out worldwide.
He makes ALL PU bushings for 201 and 124 chassis as well as some others that are interchangable. Also has adjustable suspension links and 201 bodykits. This guy is a treasure to the MB community.
He's taking orders right now for a December group buy of bushes so get on it quick!

https://www.facebook.com/HedgehogMotorsport

97 SL320 · #12 11-15-2013, 11:39 PM

Be very careful when replacing rubber bushings with poly. Some rubber bushings are designed to flex in operation, if you install something stiffer it will bind.

Rubber bushings are usually bonded to the inner and outer sleeve, this prevents squeaking. Poly bushings are not bonded so they will make noise.

lsmalley · #13 11-16-2013, 01:05 AM

Quote:

Originally Posted by 97 SL320

Be very careful when replacing rubber bushings with poly. Some rubber bushings are designed to flex in operation, if you install something stiffer it will bind.

Rubber bushings are usually bonded to the inner and outer sleeve, this prevents squeaking. Poly bushings are not bonded so they will make noise.

Yes, I did do done research on the stiffness of the poly components and I an familiar with its somewhat slightly stiffer properties. I am also familiar with the squeaking and plan on combating that with some multipurpose high pressure bearing grease. So I'm actually thinking of only doing just the dust boots and maybe the sway bars. There was a suggestion from a company for the flex disc, but I think I'd rather not do that just yet until I know its a good idea for sure. I do want to do the transmission mount though, as oil and spilled transmission fluids are causing the robert to deteriorate fast.

Zulfiqar · #14 11-16-2013, 01:14 AM

Just replacing all rear links with new lemforder bushings along with new subframe bushings, you will prolly be blown away how your 201 feels, The difference is an african winter night and a california spring day.

The 2 major rear links are the pushing and camber link, the pushing link literally takes the entire forward thrust of the car when it moves - using poly there can help for longevity.

TnBob · #15 11-16-2013, 01:27 AM

There are several 'How tos' on youtube on how to make your own.