Mustache bar bushings

[Jason240z]

22 minutes ago, Captain Obvious said:

I've never seen a good dimensioned sketch of the washer ends. I'd be interested if you want to make one up!

Are the two stock washers the same, or did they have different hole diameters in the middle to account for the bolt they ride on?

me neither.

 

current thinking is to buy some 70sha bar, machine the bushings, then with a large washer, bond a disc of 70sha poly to it using silka flex, creating the exact same setup out of 70sha?

[Namerow]

On 8/4/2017 at 8:18 AM, Namerow said:

I believe I read that the end washers are also NLA.

Well, not quite NLA... but close ($145!)

http://www.ebay.com/itm/Datsun-240z-280z-Differential-Bar-Stopper-Mount-Bushings-Upper-Lower-NOS-/282099223385?hash=item41ae6c8b59:g:w4oAAOSwY45USAog&vxp=mtr

[Acemon]

I'm going to revive this 7-months-old thread because I also want a rubber bushing.

I looked at one of the FSM diagrams and the exploded view seemed to show a separate inner sleeve (with a collar of some kind) going into the rubber bushing. It's an interesting idea but depending on the wall thickness of the sleeve, there might not be enough space for the rubber itself.

I wonder if a "recycled" bushing might work. With the bushing still in the moustache bar, burn the rubber out. Clean the tapered sleeve and the inside shell of the bushing. With a little ingenuity (something all Z owners have) make a jig to hold the moustache bar in place, and keep the pin centered, and maybe use a couple pieces of wax to form the voids. Pour liquid rubber inside and let it cure. I found 2-part mixes with a variety of hardness here: https://www.polytek.com/product-type/polyurethane-mold-rubbers and here: http://www.uscomposites.com/moldmaking.html. I think replacement "washers" could be made using a mold from an existing one and using a very hard urethane mix.

They might not be as ultimately good as the Nissan version, and might even have to be replaced every few years, but I think it's a better option than what we presently have.

Comments? Thoughts? Suggestions?

 

Edited March 17, 2018 by Acemon

[Zed Head]

1 hour ago, Acemon said:

I'

I wonder if a "recycled" bushing might work. With the bushing still in the moustache bar, burn the rubber out. Clean the tapered sleeve and the inside shell of the bushing. With a little ingenuity (something all Z owners have) make a jig to hold the moustache bar in place, and keep the pin centered, and maybe use a couple pieces of wax to form the voids. Pour liquid rubber inside and let it cure. I found 2-part mixes with a variety of hardness here: https://www.polytek.com/product-type/polyurethane-mold-rubbers and here: http://www.uscomposites.com/moldmaking.html. I think replacement "washers" could be made using a mold from an existing one and using a very hard urethane mix.

They might not be as ultimately good as the Nissan version, and might even have to be replaced every few years, but I think it's a better option than what we presently have.

Comments? Thoughts? Suggestions?

 

Won't you end up with polyurethane in the same places as if you bought an aftermarket polyurethane replacement?  The polyurethane replacements would probably work great if they just made them from a lower durometer (softer) polyurethane.  And polyurethane is generally very durable, as durable as rubber.

A person could make a mold from an aftermarket PU bushing then just pour a softer PU.  With a mold you could try several durometers.

By the way, there's no need to burn out the old rubber.  If you just heat the mustache bar ends the surface of the old rubber will soften and you can easily press it out as a chunk.

[Acemon]

They have a variety of compounds. One was described as being similar to a tire tread. I like your idea about creating a softer bushing in the modern style but I wonder if flexible types of PU are available as a block or a bar? It might be easier to carve/machine a few pieces instead making a mold.

What about skateboard bushings? They're also PU but they would need to be fairly flexible for the rider's weight to turn the board back and forth. There are plenty of small-scale board makers, so I wonder if one might be interested in a niche market for vintage Japanese sports car suspension parts.

[kats]

11 hours ago, Acemon said:

I'm going to revive this 7-months-old thread because I also want a rubber bushing.

I looked at one of the FSM diagrams and the exploded view seemed to show a separate inner sleeve (with a collar of some kind) going into the rubber bushing. It's an interesting idea but depending on the wall thickness of the sleeve, there might not be enough space for the rubber itself.

I wonder if a "recycled" bushing might work. With the bushing still in the moustache bar, burn the rubber out. Clean the tapered sleeve and the inside shell of the bushing. With a little ingenuity (something all Z owners have) make a jig to hold the moustache bar in place, and keep the pin centered, and maybe use a couple pieces of wax to form the voids. Pour liquid rubber inside and let it cure. I found 2-part mixes with a variety of hardness here: https://www.polytek.com/product-type/polyurethane-mold-rubbers and here: http://www.uscomposites.com/moldmaking.html. I think replacement "washers" could be made using a mold from an existing one and using a very hard urethane mix.

They might not be as ultimately good as the Nissan version, and might even have to be replaced every few years, but I think it's a better option than what we presently have.

Comments? Thoughts? Suggestions?

 

Hi Acemon, I am thinking same thing, I hope some one can recycle rubber bushing, same for all the mounting parts like for engine , transmission, rear final drive etc.

Sorry for uploading many pictures, they are my questions and studies.

My 1970 Z432 and 240Z, both have later style upper and lower stopper for the bushing, this is not original but I took this solution because

it worked quite well for deleting noises and vibrations.

Kats

Edited March 17, 2018 by kats

[jerz]

Just to add to this thread that European-specification cars, at least from 07/71, were equipped with solid rubber inserts between the concentric metal bush parts, part number 55476-E4102, which probably helped to firm up the suspension.

[Patcon]

2 hours ago, jerz said:

Just to add to this thread that European-specification cars, at least from 07/71, were equipped with solid rubber inserts between the concentric metal bush parts, part number 55476-E4102, which probably helped to firm up the suspension.

 

Good info, much easier to fabricate too.

@kats

That is excellent info and the pictures are outstanding!

[Zed Head]

That's one of the odd things about the mustache bar.  Nissan shows the best picture of it in the Rear Axle and Suspension chapter.  But it's not really a suspension component.  So tightening up the mustache bar bushings won't really tighten up the suspension, except for stopping the diff from flopping around during spirited driving.

I wonder if Nissan kept that solid bushing from 7/71 on or if they switched back to a looser one later.  The early cars had the forward mounted diff, which caused its own half-shaft vibration problems.

[jerz]

Yes,

Quote

2 hours ago, Zed Head said:

I wonder if Nissan kept that solid bushing from 7/71 on or if they switched back to a looser one later.

in Europe, according to my R-Drive factory fiche (see below), Nissan retained the solid rubber bushings until the S30 ceased production in1978. It is a good point you make about the moustache bar not actually being a suspension element.  

[Acemon]

Thanks to all for that great information. It explains a few things on my '71, which has the stoppers with the large ridges and solid rubber bushings. It also explains why some of the nuts and bolts were nearly loose - the PO, or the previous PO, must have replaced the bushings and stoppers but never really finished the job (or the car). After seeing these pics I'm going to keep what I have and see how they work when the car is back together.

I'm still going to order some of the rubber compound that's supposed to be the approximate firmness of a car tire and do a little experimenting to see how similar it is to the bushing material.

[Captain Obvious]

I've got a moustache bar here from a 74 260 and it has the solid bushings. I don't know for positive, but I believe they are the ones that came from the factory and have never been replaced. I'm assuming they softened the whole mounting scheme over the years to reduce noise from the diff. I'm guessing they just kept reducing the contact points over time (with slots in the bushings and wavy end washers, etc) until they got the noise down to where they stopped getting complaints?

I'm getting ready to put the slotted bushings in my 77 bar, but I need to figure out something for the upper and lower rubber washers first.

Acemon, Were you thinking of trying to mold up something for the wavy washers too, or just the bushings? Also, the material you ordered... Is it rubber (that needs to be vulcanized), or is it polyurethane?