# @Airlift - Why are the strut bearings made of plastic???!!!



## Forty-six and 2 (Jan 21, 2007)

I have to call you out on this question. I'm sure EVERYONE that uses your front bags is dying to know why their bearings are made of plastic that fail within 5-10k miles?! There seriously needs to be a very good reason for the use of what seems to be completely senseless choice of material.

Parts in question...




I need a good reason as to why I should not have these made of a suitable metal...


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## trefive (Nov 15, 2010)

I believe these aren't plastic, but a material called delrin that has lubricant qualities. My other guess of why they use these opposed to a bearing is to gain maximum drop from the struts as the bearings will typically take some thickness thus prohibiting the drop.


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## VR6OOM (Nov 8, 2002)

I'm in the same boat. I've replaced the drivers side "bushings" 6 times now over the last 2 years. The passenger side only 1 time. This most recent time I lubed the **** out of them with heavy grease. Each time I replaced the driver side, the noise returns with different levels of severity. I stick to their install instructions and only tighten the top nut air'd out to 25 ft lbs as well. I use the two supplied thin washers because once I install the circlip, everything is flush and locked in. The top mounting plates are new too but that didn't help. The strut wiggles around inside the strut mounting plate just slightly.

What I've discovered is the noise _GOES AWAY_ if I do not adjust the air pressure. If I air up or air out, the noise returns for about 50 miles. I haven't touched my air switch box for almost 2 weeks now since this discovery. Prior to this discovery I went on a front end rebuilding kick because I was thinking it wasn't the airlifts. Alas, it is. My entire front end is new minus the steering rack. Once I put all the new parts in (minus new strut bushings) I went for a test drive and the noise was still present. I then put the bushings in and there was a 75% improvement in noise reduction.

I've had email discussions with Jeff and the only real solution is to send in the strut for examination. But with this problem prevalent on so many of their applications, I'm shocked they haven't determined the cause of the noise. I'd be a guinea pig, but I'm not in a position to send them this strut.


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## Forty-six and 2 (Jan 21, 2007)

Ok, so the logic behind using the "plastic" "bearing" is for it's self lubing qualities, due to not using a ball bearing because of "packaging" reasons. 

Is there any reason a stainless replacement should not be used? It would certainly need a suitable grease, and possibly a groove machined into it, for grease retaining purposes. Possibly use a teflon shim between the two bearing plates. 

I am not having noise issues, but am having a good deal of play, when on a jack. I can only imagine airing out on dry pavement, while parked, exerts a tremendous amount of pressure and stress on the ridges of the bearing plates causing them to fail. Adjusting your height while rolling does not allow the energy to be stored in the bearing. 

Any thoughts on this Airlift? I'm sure one of your engineers is capable of solving this problem. Having your customers constantly needing to rebuild their bearings is a bit absurd! Reputation should be a higher concern than rebuild kit revenue...


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## hyphytrain203 (Jun 9, 2003)

Forty-six and 2 said:


> Ok, so the logic behind using the "plastic" "bearing" is for it's self lubing qualities, due to not using a ball bearing because of "packaging" reasons.
> 
> Is there any reason a stainless replacement should not be used? It would certainly need a suitable grease, and possibly a groove machined into it, for grease retaining purposes. Possibly use a teflon shim between the two bearing plates.


I know you're upset, but you are going about this all wrong... You should really talk to someone at Airlift with your issue before you start making design suggestions to their engineers. You clearly have no comprehension of the dynamics of the upper strut mount nor do you have an understanding of the materials you are suggesting.


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## Forty-six and 2 (Jan 21, 2007)

Maybe, maybe not... If I were to simply call airlift, it would end up as a one sided conversation. Meaning that they may explain to me their material choice, but highly doubt they would even consider any change to the design, due to me being a "consumer". It would get me no where with resolving this issue.

I believe that if you have a complaint about something, you should provide an idea for how to make an improvement...

You clearly have no understanding of the dynamics upper strut mount or materials I suggested. Stainless is a highly corrosion resistant dense material. It would better resist the forces that cause the original bearing to fail. Thus being a candidate for material substitute. The suggested grooves are simply an idea for grease retention.

As for the teflon shim... Teflon is a material used in the stainless races of spherical bearings. A bearing that designed rotating rather than spinning. The strut bearing is a bearing that simply rotates as the car is turning. I'm sure you can understand the similarities. Teflon is used for it's self lubrication qualities. In the case of this stainless strut bearing, this would be necessary. 

My brainstormed solution may need it's adjustments, but I believe has address the two major concerns that are needed to be a more reliable replacement. First the strength of the stainless, and two possible solutions for lubrication.

I understand the majority of enthusiasts are completely satisfied with being a consumer. I am not... This thread was started in hopes to start a discussion on a more suitable bearing replacement, with or without Airlift's input. I figured due to the failure rate of the current material choice, the community would be far more receptive to a more reliable replacement discussion.


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## VR6OOM (Nov 8, 2002)

As confused as to how / why they fail. With the naked eye, comparing the new bearing kit to the used one I can see no difference.


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## ocdpvw (Jul 19, 2005)

My suggestion to you is, if you you are so convinced that your suggested use of materials and/or redesign is the solution do some independent studies. Test your design, prove it then sell it to Air Lift or as an aftermarket replacement. Air Lift I'm sure has good reason for the design and materials of all components. Good luck.


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## SMG8vT (Oct 8, 2004)

FWIW I've been running HPS fronts for 4 years using OEM strut mounts / bearings with zero issues. Maybe the engineers at VW knew what they're doing? If a setup isn't broken don't fix it.


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## 89turboteg (Jul 1, 2009)

How old are these struts? I know they have gone through quite a few design changes as well as strut manufacturers. Are these their most current design?

From what I remember, Airlifts original design from about 10 years ago used an actual strut bearing. It was a chrysler I believe. They replaced that with a delrin bushing in the same dimensions of that bearing. Since then, they have played around with a few different designs. Why? cost most likely.

Now my 2 cents.
I agree that finding the right material is difficult, but in this case I don't know that the noise can be blamed on the bushing. I have dealt with a few different problems with their strut designs and its tough pinpointing it. Just like someone said, if you dont air it out of lift it the noise will go away. In that case, the bearing isn't changing yet the noise goes away. By taking it apart and installing a new bushing, are you solving the problem or just making a change that causes it to go away for a short period of time. Steering the vehicle and cycling the suspension while driving moves the bushing yet it still doesnt make noise unless its aired out. That makes me wonder if its something with the shock when it compresses.

Delrin has been used for suspension bushing for a very very long time. Teflon would work, but its more expensive. Telfon and Delrin are very similar in their lubricating properties, Delrin being slightly harder. 

From experience, an exposed greased bearing or bushing is less than ideal in the environments cars deal with. Any dirt, dust, sand and debris will get stuck to it and eventually work its way into the area and destroy the bearing. On the strut cars I bag, I prefer to go with an off the shelf bearing but finding one that is compact and allows the most drop is always the challenge. In Airlift's case, I think they are going for the most compact cost effective option possible.


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