My SPF1590AK's are doing really well since I installed them in November. Same ride quality as OEM. No signs of any collapse yet. They came with the orange colored bearings which I have seen some information that these may be newer updated bearings. I am happy with mine, would recommend.

 

One thing I learned the other weekend , when I did a mount and spring change. I found the AK and BK mounts are 2 different heights. The AK polyelast are the stock height.
The firmer Poly BK mounts are about 3/8" shorter. So if you want to close the front fender to tire gap a bit. the BK mounts are your ticket. If you want to restore ride height and performance from collapsed mounts. the AK are what you want. The AK also perform close to OEM rubber mount ride quality. Rubber mounts will always collapse because of the material. The 2 year old BK mounts I removed showed almost no wear. Just signs of the upper and lower washers surfaces. Clean and re-lube the bearing and they are ready to go back into service. Both the AK and BK mounts are great products.

 

Are you referring to the uninstalled height? Do you think the AK poly mounts compress to roughly to the same installed height as the stiffer BK poly mounts?

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Installed my SPF1590AK strut mounts today. Probably driven only 20 miles total, but they are quiet and smooth as stock. I'll try to update with more time and miles, but these seem like the perfect aftermarket mount.

 

That's a bummer. I think I ordered mine from that same site. Got them quickly. I am sure they have periodic stock orders from Australia and do not adjust the website based on inventory. It always says In Stock!

 

That's where I ordered mine from. They even sent me 2 replacement bearings free of charge (which I asked to pay for) when I dropped the damn thing and it exploded all over my garage.

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OMEGA, if the car is too low, do not install the BK's . It will make it even lower, which sounds like exactly what you don't want. Stick with the AK's

 

These are not Whiteline, they are SuperPro

 

One of my so-called "improved design" mounts just collapsed after less than 9 months so going for the SuperPro SPF1590AK ones and hopefully not have to do the job again for years!
Colin

 

So what was the brand so others won't be fooled into wasting their time and money?

 

I've recently install the superpro polylast bushings and so far I'm happy and haven't had any issues.

 

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?