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New mustache bushing updates?

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    I firmly believe there are other options for rubber moustache bar bushings out there but the problem is figuring it out.

    The original bushings pressed in (lightly), and then were swaged over for permanent retention. I bet a workable solution would be to use a new bushing of "similar, but slightly smaller OD" than the original and press the new one into the remains of the old bushing. Kinda like what you do with poly, but do it with a new rubber bushing instead.

    All that needs to be done is for someone to find that "similar, but slightly smaller bushing".

    I saw some pics of Miata diff mount bushings that looked interesting... Anyone have a Miata that could measure some bushings?

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    7 hours ago, AK260 said:


    Now that would be very cool if it would stand the stresses!! emoji106.png

    I can't remember who it is (anybody?) that is reproducing the small rubber parts but he would probably have the experience to make an attempt at it.  

    Here's another good link.  Understanding how to create a good mold, following instructions, and knowing what can screw things up (moisture, contaminants, etc.)  are the key.

    https://www.fibreglast.com/product/introduction-to-urethane-casting-resins/Learning_Center

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    Here's a start along the lines of what CO has been suggesting, the google search below.  It might be distasteful to many, because it seems "hacky," but a person could fill the void of an undersized bushing with metal-filled "space-age" epoxy (AKA JB Weld) and probably have a nice solid bushing assembly.

    https://www.google.com/search?q=motor+mounts (browse the images)

    https://www.jbweld.com/product/steelstik-epoxy-putty-stick

    https://www.jbweld.com/products

     

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    We are talking about replacing the original bushing with something that has similar characteristics. We know the PU aftermarket bushings transfer a lot of diff noise to the body so making any bush out of PU doesn't seem to has any advantage.

    I have made PU insulators for the fuel lines and other stuff for my own 280Z, but getting it to hold to the metal components enough to take the stress would be hard to achieve.

    It would need to be a part from another car with a similar purpose. For example the original positon for the bolt was in the vertical position, otherwise it would probably fail quickly due to stress it was not designed for.

     

    IMG_0012.JPG

    DSC_0884.jpg

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    I have used 2 part polysulfide rubber on teak boat decks and understand it's also used to glue up lap joints on the exterior skins of commercial jet fuselages because of its strength and flexibility. Probably too soft for this application? 

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    1 hour ago, EuroDat said:

    We are talking about replacing the original bushing with something that has similar characteristics. We know the PU aftermarket bushings transfer a lot of diff noise to the body so making any bush out of PU doesn't seem to has any advantage.

    I think that the commercially available replacements bushings were all made from a hard (high durometer) PU just because it was easy and cheap.  Probably chosen for a single application like the smaller front control arm bushings then they just started looking around for any rubber part that could be replaced, using the same material.

    You can get PU in super-soft to brick hard.  An 80A would be pretty soft but firm.  PU's are very versatile, you can't discount all PU's because somebody in the past used them for the wrong purpose.    You just have to pick the right one.

    https://www.polyglobal.co.uk/a-guide-to-shore-hardness/#:~:text=Polyurethanes are most commonly used,maintain their profile under pressure.

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    6 hours ago, Zed Head said:

    a person could fill the void of an undersized bushing with epoxy

    I was picturing making a metal sleeve with an OD such that it pressed into the original outside shell (which you would leave in the moustache bar just like for a poly install) and an ID that would accept a smaller bushing pressed into place. I don't think I would trust epoxy there.

    The thicker the sleeve, the smaller the bushing could that be used. I would want to keep it as close to stock as possible, but just something available instead of unobtainium!

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    2 minutes ago, Captain Obvious said:

     I don't think I would trust epoxy there.

    No offense intended to anyone that has posted on this topic.  But some of these things just need to be experienced to be understood, I think/guess.  Carving up a piece of solid metal leaves an obviously strong part behind, made of metal.  But, if you go out and buy a piece of Steel Stick, or one of the other metal-filled epoxies, and try it out you'll understand how strong it can be, if prepared properly.  "Epoxy" is a nebulous word, the variety is large.

    The same goes for polyurethane.  Rubber is used in the automotive industry because it's cheap.  If you've ever worked for a company that supplies automotive parts you'll understand how every fraction of a penny matters to the automakers.  They'll spend hundreds of thousands on engineering staff to design a part made from the cheapest materials.  Because the volume of parts is so high.  Making rubber parts cost quite a bit in tooling also.  Rubber parts are not poured, they are formed via pressure from rubber sheet or other solid form, and cured using heat.  I don't think that anyone is going to reproduce the rubber parts, in rubber.

    I'm just posting options.  But nobody can really discount them off-hand without taking a closer look.

    When I was messing with my mustache bar I bought some big rubber washers from the local hardware store and stacked them up to take up the space that the worn out scalloped washer used to fill.  AK260 could try that instead of carving up a PU bushing.  There are endless ways to get the big old chunk of mustache bar steel to stop moving around, clunking, but still avoid transmitting sound.

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    Here's a shorter thought - Nissan got rid of the mustache bar design when they went to the ZX body.  And they modified the parts a few times over the years. 

    It's really just a bad design from the beginning.  Simple ideas should be possible for easy improvement. 

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    I've often wondered whether the problem with aftermarket polyurethane bushings not the fact that they're made from polyurethane, but that they're made from the wrong polyurethane.  The traditional suppliers of these PU bushes have always skewed their products toward the performance buyer.  The result is a vehicle that's hard to live with on real-world pavement.  I'm sure there are lower-durometer synthetic materials -- PU or otherwise -- that could be cast from the same molds.  Unfortunately, supporting a second product line called 'street' would cost a lot of money.  The 'performance' segment of the market is, arguably, a lot bigger and certainly more lucrative.

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    12 hours ago, Zed Head said:

    It's really just a bad design from the beginning. 

    Agreed. I'm not a mechanical engineer, but my design sense tells me that they designed it for predominant forces in the wrong direction. They should have designed the bushing orientations for predominant forces in the up-down direction (both for gravity and for driveline torque) Instead, it seems they designed it for lateral forces first and then up-down second.

    They fixed that with the ZX mounting scheme and I've pondered a little on ways completely change the Z to a different scheme. But for now, just finding a modifiable bushing that could be adapted to the existing design would keep me occupied.

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    3 hours ago, Namerow said:

    The traditional suppliers of these PU bushes have always skewed their products toward the performance buyer.  The result is a vehicle that's hard to live with on real-world pavement.

    I think the biggest problem is that everyone thinks "poly is better than the crappy soft stock systems".

    Just ask everyone. It's all over the internets.

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    Lucky for me I have no previous experience driving with stock rubber bushings. All my bushings were replaced with poly or solid mounts so the NVH (whatever it is) will be the standard in my finsinhed ride! lol

     

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    AK260 could try that instead of carving up a PU bushing.  There are endless ways to get the big old chunk of mustache bar steel to stop moving around, clunking, but still avoid transmitting sound.

     Well funny you should say that chap! The other eve I was having similar thoughts and ordered some of these for that exact reason!  

    b2465748ae77ca2d369f259d7da1f223.jpg&key=748b5e971d50203870f513a49221c266df128e84a8adf9239d90990d8aae97c0

     

    Interestingly, I am making my own RT mount equivalent as my rubber insulator had totally failed - now that insulator is a true example of bad design working in the opposite direction. But I guess 43 years is 43 years wherever the rubber is.

     

    75c41c6a64e483b9ab480bf20ac4cddd.jpg&key=f5f5f4431ab696c471f297f70b822f163a4f61d76dca98039f5a43cc6a051530

     

     

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    The point being that I bought the bushing used in the TTT mount and I find it to be rock solid. So I’ve bought more of those rubber washers above with a smaller ID to space it out with - that way I get a little bit of give for reducing high frequency noise but the solid resistance to lift of the red poly bush.

     

    Here she is, mocked up out of aluminium and masking tape ;) final version will be 3mm steel. This is definitely stronger than the giant rubber band ;)

     

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    I call this the AK mount !!

     

     

     

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    Hey Guys, quick update on the reproduction rubber bushings. Heard back from my contact in Nissan USA.

    Bad news is that there is not a lot of information on the mustache bushing parts within the US organization because everything was produced in Japan and "sold" to the US legal entity, so limited visibility.

    Good news is they are following up with some contacts within Nissan Japan to track down the original supplier and minimum order quantity to reproduce. 

    At some point, we are going to need an estimate of how many potential orders the Z community might have for these parts if they could be made available. Is there a polling option within ClassicZCars or something that we could set up to send out to the community? Was thinking we could also reach out to Courtesy to see how many requests they get for these things each year.   Open to other ideas!

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    This is a great thread.  I want to replace all the rubber suspension parts on my ‘75 280Z, but so far, I’ve only replaced the f/r sway bar mounting bushings and their drop link bushings.  Also replaced the compression rod bushings.  I have the inner transverse link bushings to install soon,  Still lots more to do to freshen up my suspension.  (Rubber) parts lack of availability has been the major hold up.

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    8 hours ago, dmuzial said:

    At some point, we are going to need an estimate of how many potential orders the Z community might have for these parts if they could be made available. Is there a polling option within ClassicZCars or something that we could set up to send out to the community? Was thinking we could also reach out to Courtesy to see how many requests they get for these things each year.   Open to other ideas!

    That would be terrific if this happened, any idea what their minimum run would have to be?

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    That would be terrific if this happened, any idea what their minimum run would have to be?


    Pretty sure there would be a market in Europe too if the price isn’t silly with import duties.

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