Apparently, the Pedders heavy duty rubber strut mounts (5851) are better than the other rubber strut mounts out there. I purchased some back in December along with their bearings (5030). I currently have the Whiteline strut mounts installed and I agree with your assessment as it relates to NVH.

I'll be installing the Pedders strut mounts this weekend along with Koni strut inserts and shocks, among other things.

From Pedders as it relates their redesigned heavy duty rubber strut mounts (5851) and bearings (5030): http://d22enj1fxubdc2.cloudfront.net/sites/default/files/docs/product-release/tn1295493082.pdf

I bought mine at GTOG8TA.com as they agreed to price match ultrarev.com's shipped price.

 

I'm curious what other suspension mods you have done, I'm running stock other then the Whiteline Poly strut mounts and the difference in NVH is non noticeable to me. I'm wondering if it's worse if you add other stiffer suspension components with them.

 

Stock FE3 suspension. When I replaced the collapsing OEM mounts, my struts were still in pretty good shape.

SuperPro (I think) has two mounts - one that is like ever other mount and one that is sort of a "lite" poly mount. It's construction more closely follows the original design and it is supposed to add very little NVH. Part number should be SPF1590AK.

Good information and definitely something I'll look into if the Pedders HD rubber strut mounts fail earlier than expected.

That material reminds me of a similar light blue material that Moog uses in some of their bushings for other vehicles that is meant to last like poly but perform (NVH) like rubber.

 

SuperPro (I think) has two mounts - one that is like ever other mount and one that is sort of a "lite" poly mount. It's construction more closely follows the original design and it is supposed to add very little NVH. Part number should be SPF1590AK.

 

Carrying on with this. Based upon the post and review in the following thread, the SPF1590AK (Polyelast®, another trademarked name like polyurethane): strut mounts seem to be much better than the SPF1590BK (polyurethane) strut mounts. The SPF1590BK (polyurethane) would be similar to the Whiteline poly strut mounts and others out there. While the SPF1590AK (polyelast) would be like the OEM rubber (little-to-no NVH) but will actually last long. It is newer and cheaper as well.

SPF1590AK (polyelast): GTO Front Strut Mount with Bearing | SuperPro SPF1590AK

SPF1590BK (polyurethane): SuperPro SPF1590BK Front Upper Strut Mount w/ Bearing. SuperPro SPF1590BK

In hindsight, I kind of wish that I went with the SPF1590AK (polyelast - NVH of OEM rubber but long lasting) strut mounts since I'll be swapping everything out this weekend, but I'm just over the Whiteline polyurethane and looking forward to getting back to rubber (Pedders rubber HD strut mounts; new design). If and when these Pedders HD rubber strut mounts fail, I'll move over to the SuperPro SPF1590AK (polyelast) strut mounts.

 

Personally i have bone stock FE2 80k original parts (other than Whiteline strut mounts) , which will all be replaced soon with Koni's and possibly Tein springs.

 

I've bought some SuperPro Polyelast's, but it'll be a few weeks before they get into the car. They're essentially the same hardness, and feel just like the same material.

When I get the other mounts off, I'd be able to tell for sure what the differences are if any.

 

Well, the differences between the SPF1590AK (polyelast) and SPF1590BK (polyurethane) are quite obvious.

See the all rubber/polyelast construction (SPF1590AK - polyelast) and the dull rubber-looking material vs. the metal construction/sleeve under the bearing (SPF1590BK - polyurethane) and the shiny and hard plastic in the following pictures for comparison.

SPF1590AK (polyelast):

SPF1590BK (polyurethane):

Enough to increase NVH in my opinion. I suspect your OEM rubber ones will be similar in construction to the SPF1590AK (polyelast) strut mounts.

EDIT: Pedders 5851 HD rubber strut mounts for comparison.

strut mounts at 4000 miles - LS1GTO.com Forums

 

I was referring to the stock mount style versus the PolyElasts.... I'm not blind. But perhaps I didn't clearly specify.

 

I know you were. I was just providing some insight for anyone else.

When I change mine in the spring, I will be going with a set of Moog's.

There is zero evidence that the Moogs have been redesigned compared to the original GM mounts. And mind you, GM made a revision to the mounts and they still fail from what I've read. You'd be really wasting your money and time if you end up going with the Moogs (or Mevotech or anyone else that hasn't been mentioned above).

Your best bet is either Pedders (heavy duty real rubber that has been redesigned) or SuperPro SPF1590AK (polyelast, not to be confused with polyurethane: OEM rubber feel and comfort but long-term durability of polyurethane).

 

When I change mine in the spring, I will be going with a set of Moog's.

 

And you'll be replacing them in no time again.

 

Like Jova, I'm waiting for spring to put my polyelast bushings in too. Just a thought, does the latest Chevy SS still have bushing problems? Maybe the latest GM one won't collapse as fast as the original design , '97 Cadillac Catera

 

They seem to be having the same issue even though theirs is a different part number.

Strut Mounts Issues? - Opinions wanted

EDIT: Same new part number for all: 92272959

 

Well, ordered up some Polyelast mounts tonight and will be installing them sometime in the next few weeks, so I will be sure to post my impressions afterwards.

 

Seems that half the folks that switched to poly strut bushings notice increased NVH and half don't. I'm in the half that didn't notice any change in NVH. I want to point out that I watched my factory rubber bushings collapse so by 8500 miles I changed to poly. So I can't recommend rubber for strut bushings. They won't last.

 

Seems that half the folks that switched to poly strut bushings notice increased NVH and half don't. I'm in the half that didn't notice any change in NVH. I want to point out that I watched my factory rubber bushings collapse so by 8500 miles I changed to poly.

I agree with this as some people are more sensitive than others.

So I can't recommend rubber for strut bushings. They won't last.

That is quite subjective and vague and it all depends on how we classify strut mounts. From what I've read and agree with, strut mounts are a wear item, just like brake pads and rotors, struts and shocks, tires, etc.

While Pedders uses the same grade of rubber as the OEM piece, the surrounding ridges have been redesigned. One poster (LS1GTO.com) explained it as viewing the surrounding edges as a series of waves.

The OEM design troughs (sunken areas) are wider than the crests (raised areas). The Pedders strut mounts have wider crests and narrower troughs. It is the crests that make contact with the body of the vehicle and thus having wider crests provides a larger contact area. Also, Pedders' strut mounts have a larger ferule.

But yes, the Pedders strut mounts will also fail in time.

The SuperPro SPF1590AK (polyelast) strut mounts are a good replacement if they truly have the same feel as OEM rubber. I'll wait for some more reviews since I already have the Pedders mounts and will be installing everything tomorrow.

 

I honestly didn't notice a change in NVH going to poly strut mount bushings. And I'm pretty darn picky about NVH.

 

Polyelast is essentially a polymer synthesized from polyurethane and elastomeric rubber. I did some reading, and it essentially is meant to act like rubber and resist breakdown and deformation like poly. There are lots of variations, so I didn't dig that deep into the actual composition.... as if that matters LOL.

Since here in NC I've only had one set of mounts fail, I would posit that the chemical exposure in certain areas leads to advanced wear. I'd say rock salt from areas that use it would be the best known culprit.

Like GXP25 said... it's a wear item like brakes, tires, etc.... Not much you can do but replace them when they go.

 

Actually, Polyelast is a thermoplastic as well.... As far as the properties of each, I wouldn't read the marketing brochure to discover what the difference really is. You have to look at the actual engineering bulletins on each material....

Were the marketing brochure's to be believed, everybody has the best part available.

Edit... P.S. for the record, I can't really find the appropriate EB since there are so many variations of PolyElast that I don't know which one to pick.... aside from asking for that EB from the manufacturers using it (if they'll provided)

 

I think I am going to get a set of Whiteline Poly bushings. I have all Whiteline bushing in my GTO and they are great.

 

I installed the Whiteline poly strut mounts in the G8 this past weekend. Other than my steering feeling a bit smoother, I cannot tell a difference in the ride quality.

I think the Whiteline poly material is a softer durometer. On my GTO, I found also that the Whiteline poly subframe bushings also did not give a harsh ride.

I think Whiteline is the way to go.

 

Well it looks like the Pedders mounts are starting to collapse. I'll be looking into the SuperPro SPF1590AK (polyelast) mounts when the replacement (warranty; it was leaking oil up top) Koni strut insert comes in.

 

Well it looks like the Pedders mounts are starting to collapse...

How much time elapsed when the Pedders heavy strut mounts started to collapse? Also, do they require the specific Pedders strut mount bearing (5030) or are most regular bearings compatible?

 

The Polyelasts are good quality parts, but I didn't like the bearings. I reused the bearings I had (inspected them thoroughly) since they had only been in the car for about a year.

It might have been just me. Anyhow, overall the quality and feel aren't going to be identifiable different.

 

Aren't there different sized bearings (the plastic rings)?

I currently have Whiteline polyurethane strut mounts and their bearings (sitting in the garage) and the Pedders strut HD rubber strut mounts and bearings.

 

It wasn't the size of the bearings. Mostly, it was the overall perceived quality of them. They were not smooth in operation and didn't handle compression well.

The mounts are as good as can be expected.

We'll see how they measure up in longevity. Any mount will eventually wear out, but I expect these to never have to be replaced again (or at least not in a reasonable amount of time) given the amount of driving I intend to do going forward with the G8. 4-6k driving a year means these should last a good long time.

 

It wasn't the size of the bearings. Mostly, it was the overall perceived quality of them. They were not smooth in operation and didn't handle compression well.

Oh, I honestly thought that there was a size difference in the rings (not the actual balls) which made then incompatible with the other mounts out there.

The mounts are as good as can be expected.

We'll see how they measure up in longevity. Any mount will eventually wear out, but I expect these to never have to be replaced again (or at least not in a reasonable amount of time) given the amount of driving I intend to do going forward with the G8. 4-6k driving a year means these should last a good long time.

Yeah, the Whitelines I pulled off looked a bit worn on the sides but they were nowhere near collapsed, which was good.

My ride quality was deteriorating and I attributed it to the strut mounts. Of course, it was the struts. However, since this point of contact was rubber from stock, why not reinstall rubber, especially considering the forces involved. But now that there's a mount with the durability of polyurethane and the alleged comfort/NVH of rubber, why not?

 

The chemical reliability will only really be important to folks who live and drive in climates that consistently use rock salt.

Here in NC, I have learned that rubber holds up very well.

As far as road comfort, the front end responds about as expected after installing the Super Pro control arms and radius rods. It's harsher than before, but not to such an extent that it is noticeable at normal speeds. So, I would say that the mounts are indeed comparable to rubber as far as road feel is concerned.

Do they "deflect less?" Considering the hardness of the original stock mounts, not really. It isn't like the OEM stuff was flimsy.... After completing an entire bushing job, I can honestly say the mounts have had an impact that is indiscernible.

I bought them more as an experiment, so I'd not say I wouldn't buy them again. Come back in 7 years and I'll tell ya LOL....

 

so I'd not say I wouldn't buy them again. Come back in 7 years and I'll tell ya LOL....

So you'd buy them again? Double negatives. :laugh2:

 

Bearing are rarely an issue. The only time people have problem is with install errors. If the mount is not fully seated on the spring plate, the bearing can catch and break on the spring plate inner lip.

 

A long while ago, I got into a debate with an engineer. We were talking about Micron Gauges, and he insisted that I had my terminology wrong when describing an aspect of the sensor. He was insistent in his correctness, and I yielded.

He came back to me and apologized and he said, "Mike, stick to your guns. You shouldn't yield just because you think the guy next to you has more experience or that he is smarter than you. You were right."

I learned to stick to my guns, and I'm doing it now.

I followed the installation procedures correctly for the bearing installation, and I verified it twice. These two bearings were the only ones to have ever failed on me during that procedure, period.

Consider it what you want, but sometimes there are other reasons problems arise than just somebody's error.

That said, we're good, I'm not mad. However, I am opinionated, and this time I am sure.

 

That said, I am 100% willing to entertain the idea that I simply got a defective set of bearings. Still, it was my experience, and I was sharing it.

 

Replaced the partially collapsed Pedders HD strut mounts yesterday with the SuperPro SPF1590AK (polyelast) along with replacing the failed Koni strut instert (warranty).

These mounts feel good. I still have a clicking noises when braking and turning sometimes and I think it may be the driver side sway bar endlink.

I also changed out the sunroof motor with a 2008 motor (set and forget); good mod and easy to replace.

 

Wow
This is an active thread in 2017, 8 years after the G8 dried up and proves there is still a lot to learn as well as aftermarket support.

Want to have my LCA fix done soon at a dealer and seeing if I can get some new strut mounts on hand for them to install at the same time, instead of doing this myself. Was going to just get some stock replacement ones or the rubber ones on gtog8ta.com but kept hearing about Superpro bushings, which I hadn't read of on here until more recently when I actually started paying attention to the forum again for the first time in a few years.
Found this thread today and pretty much convinced I shouldn't want real heavy duty poly bushings because the roads here are horrendous.
Looks like the softer ones will work for me - it's just a regular driver, nothing crazy.

 

Unless mentioned in another post, the G8/VE listings at SuperPro show both mounts (AK & BK versions), but VF (Commodore/Chevy SS) lists only the AK mount. FWIW.

 

Possibly due to the updated bearing that comes standard in the VF.

I look forward to seeing the long term results from the updated GM design.