TheSamba.com :: View topic

Thu Dec 14, 2023 5:46 pm

raygreenwood wrote: DesertSasquatchXploration wrote: I never called anyone out (Lets make that perfectly clear) but MR raygreenwood seems pretty miffed. The self proclaimed plastics expert that has done nothing to solve our (gaslighted) (shifter bushing problem).

I'm not the bad guy here. Delrin is not superior. I'm simply Stating the replacement bushings are perfectly fine grease them during installation they will last your many years. You can use your VW to get a Christmas tree take the family to mini golf or your wife on a date everything's fine.

End of Conversion

I love that....."end of conversation" :lol: ....as if the choice is YOURS or you have any control over it at all! :wink:

First....not miffed at all!

Second!....where did ANYONE......ANYONE.....state that Delrin/Acetal was ....."SUPERIOR"?

Point it out please!

This thread is NOT about me wanting to make shifter rod bushings out of Delrin. It's about the fact that someone already has....and it's about whether that material will work or not. Yes....it most certainly will work. How long and how well depends directly on which version of Delrin is being used.

Also unsaid here, which lubricant is used will factor heavily in how well ANY of these plastics work. In my experience a dry graphite or MDS would be best for any plastics mentioned here.

If you look carefully at what I posted both here and in numerous other threads concerning these shift bushings ....I actually subscribe MOST to an injection molded nylon alloy....something like Mitsubishi Nylatron 105 which is MDS filled nylon 66 cast in billets for machining or granules for molding. You can also get it in filament now.

Yes it "can" be machined but is better molded. Actually all of the plastics mentioned here....even Delrin....would be better and tougher if molded. Machining is not ideal for any of them for this part....but for the cost most are willing to pay it's the best answer.

By the way....if you have any experience at all with what's currently available as stock bushings for quite some time.....you would know as others have stated as well....that what's available (not all but plenty of it) has serious problems. Some of them are the wrong material altogether.

Of course.....as a "self proclaimed"....machinist expert.....you should already know this....right? :wink:

Ray

Great post Ray. It just seems like sometimes people have so much ego they are triggered and speak before reading and understanding what was said. In essence, their ego speaks before their mind does.

When I posted this thread, it was not to say Delrin of any type is superior. Just to bring awareness to a product that is available that has a possibility of being better then the current market options. When possible, i like to upgrade a part with a better one, especially when its a pain in the ass job like the bushing. Some of these cars been sitting for 30-60 years, and we need to go through everything. So researching options is important.

Also, if someone comes in the thread, and states "my stock bushing lasted 250k miles", that doesnt help a guy that just bought a bug that has no bushing cause it rotted away years ago and its metal to metal, and there is not a genuine OE German bushing on the market to at least duplicate the 250k story.

Another thing that made me MORE interested in Delrin type options, is what Chrislstf mentioned. The fact that the supplier that i bought my Bronze bushings from has switched to one of the Delrin variations tells me that he made a educated move when he swtiched. After selling bronze bushings for years, he picked 1 type of Delrin, and now goes with it only. This is educated, not random. He sold those bronze bushings for over 10 years and gathered feedback. https://www.thesamba.com/vw/classifieds/detail.php?id=1740498

Thu Dec 14, 2023 6:47 pm

jpaull wrote: raygreenwood wrote: DesertSasquatchXploration wrote: I never called anyone out (Lets make that perfectly clear) but MR raygreenwood seems pretty miffed. The self proclaimed plastics expert that has done nothing to solve our (gaslighted) (shifter bushing problem).

I'm not the bad guy here. Delrin is not superior. I'm simply Stating the replacement bushings are perfectly fine grease them during installation they will last your many years. You can use your VW to get a Christmas tree take the family to mini golf or your wife on a date everything's fine.

End of Conversion

I love that....."end of conversation" :lol: ....as if the choice is YOURS or you have any control over it at all! :wink:

First....not miffed at all!

Second!....where did ANYONE......ANYONE.....state that Delrin/Acetal was ....."SUPERIOR"?

Point it out please!

This thread is NOT about me wanting to make shifter rod bushings out of Delrin. It's about the fact that someone already has....and it's about whether that material will work or not. Yes....it most certainly will work. How long and how well depends directly on which version of Delrin is being used.

Also unsaid here, which lubricant is used will factor heavily in how well ANY of these plastics work. In my experience a dry graphite or MDS would be best for any plastics mentioned here.

If you look carefully at what I posted both here and in numerous other threads concerning these shift bushings ....I actually subscribe MOST to an injection molded nylon alloy....something like Mitsubishi Nylatron 105 which is MDS filled nylon 66 cast in billets for machining or granules for molding. You can also get it in filament now.

Yes it "can" be machined but is better molded. Actually all of the plastics mentioned here....even Delrin....would be better and tougher if molded. Machining is not ideal for any of them for this part....but for the cost most are willing to pay it's the best answer.

By the way....if you have any experience at all with what's currently available as stock bushings for quite some time.....you would know as others have stated as well....that what's available (not all but plenty of it) has serious problems. Some of them are the wrong material altogether.

Of course.....as a "self proclaimed"....machinist expert.....you should already know this....right? :wink:

Ray

Great post Ray. It just seems like sometimes people have so much ego they are triggered and speak before reading and understanding what was said. In essence, their ego speaks before their mind does.

When I posted this thread, it was not to say Delrin of any type is superior. Just to bring awareness to a product that is available that has a possibility of being better then the current market options. When possible, i like to upgrade a part with a better one, especially when its a pain in the ass job like the bushing. Some of these cars been sitting for 30-60 years, and we need to go through everything. So researching options is important.

Also, if someone comes in the thread, and states "my stock bushing lasted 250k miles", that doesnt help a guy that just bought a bug that has no bushing cause it rotted away years ago and its metal to metal, and there is not a genuine OE German bushing on the market to at least duplicate the 250k story.

Another thing that made me MORE interested in Delrin type options, is what Chrislstf mentioned. The fact that the supplier that i bought my Bronze bushings from has switched to one of the Delrin variations tells me that he made a educated move when he swtiched. After selling bronze bushings for years, he picked 1 type of Delrin, and now goes with it only. This is educated, not random. He sold those bronze bushings for over 10 years and gathered feedback. https://www.thesamba.com/vw/classifieds/detail.php?id=1740498

The interesting thing about the link to this Delrin bushing is that they make note thats its "high grade" Delrin. Of course that could just be marketing, but I make note that when looking at the pictures greatly expanded....alot of...but not all of...the surface textures are exceedingly fine and smooth.

Yes, it could just be very fine machining but I "think" it may be a molded part that may be finished CNC. The fine surfaces with a lack of striations suggest that it is not glass or PTFE filled (Delrin AF or similar) and is probably a copolymer which has better strength in the center of the part (homopolymer has a low density center or soft spot).

Either way, for this application it will be slick enough no matter which Delrin it is.

BUT...do NOT use greases...petroleum greases like bearing grease with Delrin. It slowly causes issues.

Do not use carb cleaner that may have methyl ethyl Ketone or most ketones with it to clean it. Bad for Delrin.
Acetone is good, most alcohols are good.
Brake cleaner made from perchloroethylene are kind of a B rating. They are ok just limit the time. Don't soak the part.

This is why the manufacturer of this part suggest a dry film adhesive. Silicone is no problem.

Ray

Thu Dec 14, 2023 8:26 pm

If I recall reading correctly in the past, I thought the main reason for going with the stock style bushings was that they had the most effective reduction of vibration transmitted to the shifter. How do the acetyl plastics measure up in that respect?

Fri Dec 15, 2023 5:58 am

Ray, so if I understand that last statement of your last post, the silicon grease made by Super Lube would work fine on the bushing from the original post?

I have the red plastic bushing, that was also posted in this thread, but with the thick base of my shifter, I don't get many threads for the nut on the pointed stud. I really like the snap in feature of the delrin bushing and think I'll give it a try.

H2OSB

Fri Dec 15, 2023 6:54 am

H2OSB wrote: Ray, so if I understand that last statement of your last post, the silicon grease made by Super Lube would work fine on the bushing from the original post?

I have the red plastic bushing, that was also posted in this thread, but with the thick base of my shifter, I don't get many threads for the nut on the pointed stud. I really like the snap in feature of the delrin bushing and think I'll give it a try.

H2OSB

Had to dig around. While I have used superlube on Delrin....the thing you worry about with plastics and rubbers are very specific chemicals. The only things that really cause issues with Delrin/Acetal are certain acids and certain VOC's...mostly Ketones. And, in most cases it matters how much of those chemicals are in something in put on Delrin...meaning what fraction of the chemical is the bad stuff.

On the Superlube site, they list that the superlube grease contains "essentially" "0" VOC's...which pretty much means only trace amounts. It should be just fine.

Ray

Fri Dec 15, 2023 9:11 am

I used Superlube exclusively on the rebuild of beam on my 71 Bug. I was/am under the impression that it can be used anywhere moly would go, with attention to temperature tolerances of course. I also like to use Superlube to grease things where it is nicer to avoid black grease messes. Working on the theory that at there is no sulfurous or other corrosives(?).
Anyone have reasons not to do this...I'm curious

Fri Dec 15, 2023 9:51 am

Ok, Got one from Washburns. I tried a Bug shift rod I had and it will work, but the rod must be 22 mm or .866” the whole length and round. If its over anywhere by more than a couple thou, you’ll need to fit for clearance. The Bug rod I have is over by .005” right at the end where the end is welded on and ground down. You wont get it over that without addressing it first. The rod needs to be round and clean the whole length too. Polished in the bushing area would be good

In the bug, you need to put it in with the flange facing front and the slot straight up, There are 2 notches on the side machined in to clear the side of the bracket web. If not, the bushing wont click into place. You can rotate it in the bracket if needed. It has a nice tight fit in the bracket, wont rattle.. Removing it in a Bug would be an issue, without some 90 degree pliers to squeeze it .

Its not gonna fit in a bus, as is, as the bushing has to be on the bracket first, but you could grind off the nubs to slip it on all the way and drill a couple 1/16 holes on the side for safety wire. I may do that on mine.

It may not for everybody because of too many rod variables, but with the proper clearance and lube, it would be good. I would have made the ID of the bushing about .005” or so larger to give a little more leeway. That’s where the original bushing, being flexible, allows for more variances

Would strongly recommend also fitting the bushing on your rod outside the car first to test fit. Otherwise you’ll never push it in place thru the limited access of the shifter hole

Fri Dec 15, 2023 5:02 pm

Ok, progress, after more cleaning shift rods, Ive fitted this bushing on 2 shift rods, a bug and a bus, in a freely moving manner. I did open up the bushing to fit my bus shaft about .003” and the bug rod fits just a hair looser, so not all rods are the same, I suspect later models, just got better quality tubing.

For the bus, I just took the top off the nub with a file. It still snaps in place, just need to put the bushing on first, past the bends, then add the bracket, Snap it in

I grabbed some lithium grease for a test fit. Definately not gonna wear out
Thumbs up now :D

Fri Dec 15, 2023 6:57 pm

chrisflstf wrote: Ok, progress, after more cleaning shift rods, Ive fitted this bushing on 2 shift rods, a bug and a bus, in a freely moving manner. I did open up the bushing to fit my bus shaft about .003” and the bug rod fits just a hair looser, so not all rods are the same, I suspect later models, just got better quality tubing.

For the bus, I just took the top off the nub with a file. It still snaps in place, just need to put the bushing on first, past the bends, then add the bracket, Snap it in

I grabbed some lithium grease for a test fit. Definately not gonna wear out
Thumbs up now :D

While I think you will be fine with lithium grease...and I have read thousands of accounts of people in automotive and industry using almost every manner of grease with Delrin.....its USUALLY just fine but not always.

There is a reason why companies that make Acetal do not recommend grease (unless they tell you a specific grease)...its because there is no end to the variations of what are IN grease. Saponifying detergents with all kinds of possible chemicals, solvents etc.

There are things that mess with Delrin. You need to know what's in it.

One of the things that is hard on Delrin is almost anything with sulfur or sulfides in it. It can cause swelling and flaking of the surface. Lots of EP greases have sulfur in them. You can smell it. Here are some commentary

https://www.practicalmachinist.com/forum/threads/delrin-swelling.259575/

Some of the comments in the thread are incorrect. Delrin has no issues with most coolants unless they have sulfur. Delrin also has virtually no water absorption. But also, the Nylon comment....only nylon 6 has significant water absorption.

Here is an interesting account worth reading on the practical machinist site. The issue they are speaking of...where the Delrin...even when it does not really get hot during machining...seems to change shape/dimensions.

Part of what they are seeing...yes...is that Delrin needs to be aged/stress relieved between machining steps ....sometimes....but the reason is the difference between Delrin Homopolymer and Delrin Copolymer.

A lot of basic material shops do not list exactly which one they are selling. The homopolymer cast rounds and blocks...have a soft spot in the core (different density). When you machine out that soft spot it cuts at a different rate and then allows stress movement.

Its some of the difference I was getting at a couple pages back.

https://www.practicalmachinist.com/forum/threads/question-on-delrin-af-stability.170769/

Ray

Fri Dec 15, 2023 10:29 pm

On the SuperLube:
Used that stuff for years at a bus company. Not for bearings/et-al, but lots of other uses. It's sticky, covers/seals very well for a long time, works great for grounding & as a dielectric grease(for home wiring there's something better, but...). Hard to get off something, you - for instance - even w/brakeclean. Don't get this on your cloths & run them thru the washer/drier, as it'll transfer to/onto everything.

Mostly what I wanted to mention is, the version we used, - & I still use - , is the *food-grade* grease. Used in all sorts of equipment needing lubrication that could/will come into contact w/food. Clean enough to eat, but I'd still suggest not licking your fingers clean after using it... So it should work ok on the bushing. Maybe Ray could wade thru the MSDS sheet & comment, iffen it's not the one he looked at?

TIA anyways.
Marcus...

Mon Dec 18, 2023 8:58 am

Bummmmm...

Busstom wrote: If I recall reading correctly in the past, I thought the main reason for going with the stock style bushings was that they had the most effective reduction of vibration transmitted to the shifter. How do the acetyl plastics measure up in that respect?

...P

Mon Dec 18, 2023 2:08 pm

VolksRodT wrote: On the SuperLube:
Used that stuff for years at a bus company. Not for bearings/et-al, but lots of other uses. It's sticky, covers/seals very well for a long time, works great for grounding & as a dielectric grease(for home wiring there's something better, but...). Hard to get off something, you - for instance - even w/brakeclean. Don't get this on your cloths & run them thru the washer/drier, as it'll transfer to/onto everything.

Mostly what I wanted to mention is, the version we used, - & I still use - , is the *food-grade* grease. Used in all sorts of equipment needing lubrication that could/will come into contact w/food. Clean enough to eat, but I'd still suggest not licking your fingers clean after using it... So it should work ok on the bushing. Maybe Ray could wade thru the MSDS sheet & comment, iffen it's not the one he looked at?

TIA anyways.
Marcus...

Yep...pretty clean stuff. Just a bit of teflon in it. Too much of it is "trade secret"...but it does have plenty of FDA backing. If you look in the SDS down in section 15 you will see a whole lot of "none of the ingredients are listed"...this means that none of the ingredients are listed as hazards by OSHA, FDA, NIOSH or others.

As long as something is not "listed" it means they do not have to tell you what it is. Its why SDS sheets since the change from MSDS in 2015....have no real use anymore for finding out what something is made of. :roll:

I also do not use Superlube for bearing grease...at least not heavy duty bearings .It has great EP qualities and a very good drop point...but in the peculiar manner that makes this grease very good for something like a steering box....meaning it flows and shear thins very well compared to a normal NLGI 2 bearing grease....it seems to thin out and push away from the bearing a little too easy to use for say the four big large roller bearings in the rear end of my 412 car. It seems fine for the front wheel bearings as long as you have some extra grease packed in to keep the grease from backing out of the bearing.

But for sliding surfaces, needle bearings etc....its excellent. Ray

Mon Dec 18, 2023 6:04 pm

If you look in the SDS down in section 15 you will see a whole lot of "none of the ingredients are listed"...this means that none of the ingredients are listed as hazards by OSHA, FDA, NIOSH or others.

As long as something is not "listed" it means they do not have to tell you what it is. Its why SDS sheets since the change from MSDS in 2015....have no real use anymore for finding out what something is made of. :roll:

Thanks, Ray;
I didn't realize that the info sheets have been changes to "Nothingness" & "Uselessness", but then, it doesn't surprise me anymore, either.

Marcus...

Tue Dec 19, 2023 1:22 am

Busstom wrote: If I recall reading correctly in the past, I thought the main reason for going with the stock style bushings was that they had the most effective reduction of vibration transmitted to the shifter. How do the acetyl plastics measure up in that respect?

They are hard Vibration is a definite issue why do you think VW went away from the bronze bushing? Certain grease causing swelling is a concern as well. I'm surprised MR raywood hasn't gone off about Rulon. It could also be used for those that think polypropylene is sooo terrible.

The shift rod is not perfectly round nor a constant diameter. The spring clip on factory style bushings is genius it will hold tight during all the shift rod changes in Concentricity and diameter plus dampen any vibrations. I find it funny we all praise VWs great designs yet some completely $hit on this one like they know more get real guys.

Tue Dec 19, 2023 7:12 am

DesertSasquatchXploration wrote: Busstom wrote: If I recall reading correctly in the past, I thought the main reason for going with the stock style bushings was that they had the most effective reduction of vibration transmitted to the shifter. How do the acetyl plastics measure up in that respect?

They are hard Vibration is a definite issue why do you think VW went away from the bronze bushing? Certain grease causing swelling is a concern as well. I'm surprised MR raywood hasn't gone off about Rulon. It could also be used for those that think polypropylene is sooo terrible.

The shift rod is not perfectly round nor a constant diameter. The spring clip on factory style bushings is genius it will hold tight during all the shift rod changes in Concentricity and diameter plus dampen any vibrations. I find it funny we all praise VWs great designs yet some completely $hit on this one like they know more get real guys.

Yes, vibration can be a issue with the more rigid versions of Delrin. It can also be ....and has been....an issue with the sloppy fit of the aftermarket versions of the factory bushing when they quickly wore out from being made of the wrong material (the clear-ish polyethylene versions).

Why would I go on....in this thread....about an engineering plastic like Rulon?

Though this bushing needs to be impact resistant, water resistant, low friction and fiber filled for long wear resistance ( that would probably correspond to Rulon J)......why would it need to have 500° heat resistance when it's nowhere even near a heat source....and why would anyone bother to pay the average $800+ per foot it requires to get a 1.5" diameter rod to machine it from?
Why would someone select a hideously expensive plastic that requires a surface finish on the shaft or rod it's going to be operating on....with an Ra of somewhere around 9-10 micro inches...just to survive?

......when you could simply get a 1.5" x 1 rod of the correct acetal or Delrin for about $13....enough to machine about 3 bushings. It would meet the same basic requirements of the bushing we need for what.....about 0.541% of what 3 bushings from Rulon would cost?

Or we could just machine the bushing out of essentially what the factory did.....nylon (except let's use a modern nylon like 6.6).....except maching accurately out of nylon sucks. And it's about the same hardness as using the right Delrin. It's an injection molding material. So we cant.

Or we could machine it out of UHMW like some of the GOOD aftermarket bushings have been made out of....except UHMW is worse to machine than nylon. It's an injection molding material. So we can't.

There are very few AFFORDABLE plastics available with the right characteristics to make them accurately and easily machinable for a part like this.....which is why people are working with Delrin/acetal.

You keep commenting that why don't we just use the factory bushing when it worked so well.....and it did work well.
The problem is that the "factory"......the original factory....no longer makes these bushings and hasn't for at least half my lifespan.

Every single part available since about the late 80s has been an aftermarket version, molded by a wide range of companies.....most of which (not all) have been molded out of totally the wrong materials....or even when they have been the right materials....the fit and finish has been hit and miss.

This is why there are people who are even bothering to try to make new and better versions of this simple part.

Ray

Tue Dec 19, 2023 10:47 am

vamram wrote: 74 Thing wrote: I have seen this one made in Europe, but now sold at CIP1 as well.

https://www2.cip1.com/c24-111-701-259-akit/

I've had this one installed in my '73 Super for just over a month. This is my daily driver and I put 2.5 k miles on it since the week before TG (took a long road trip), so far so good. It's a hard plastic, I couldn't begin to tell what type of plastic, and 3-d printed.

Hey @vamram if you have a moment, was that as easy to install as it looks?

Thanks!
-Joe

Tue Dec 19, 2023 11:27 am

Hey, Ray;
Possibly a stupid Q, but do you know what the specific compound the OEM bushing was made of? & if it is known, why isn't that material used to make the re-pops? Esp if it could be inj-molded, or maybe even 3D printed? IDK, is why I'm asking. The pic of the translucent bushing looks awful thin & smooth to 'print. ???
TIA.
Marcus...

Tue Dec 19, 2023 11:29 am

DesertSasquatchXploration wrote: They are hard Vibration is a definite issue why do you think VW went away from the bronze bushing? Certain grease causing swelling is a concern as well. I'm surprised MR raywood hasn't gone off about Rulon. It could also be used for those that think polypropylene is sooo terrible.

The shift rod is not perfectly round nor a constant diameter. The spring clip on factory style bushings is genius it will hold tight during all the shift rod changes in Concentricity and diameter plus dampen any vibrations. I find it funny we all praise VWs great designs yet some completely $hit on this one like they know more get real guys.
The old VW version was steel on steel with a leaf spring to dampen any ratting. I think the new plastic version was mostly to be cheaper to make, no more rolled steel edge and spot welded curved leaf spring on the hanger. The first version of the plastic bushing, for part of 1960, didn't have the spring clip. My advice is if you have that bushing and clip be sure the inside of the shift hanger bracket is smooth. The bushing will stay in place on the shift rod and rotate in the hanger when going side to side in the H pattern. Most worn out shift rod bushings seem to have been cut through at the hanger, not on the shift rod.

Tue Dec 19, 2023 2:12 pm

After playing with the delrin some more, I think on bug shift rods, that are more round, the delrin is a good fit. Not gonna vibrate, no room for that. On Bus shift rods, that are bent in 2 places, I think the manufacturing operation led to the not round condtion in the bushing area. Both bus rods I have are like this. Its not wear as the sides are over 22mm and the top/bottom measurements are under 22mm. the difference is about .020” or so.

The bug rod is dead straight and perfectly round . On the bus rod, with the delrin bushing as you move the shifter across neutral, it goes from snug to loose, to snug again. Not badly, but noticeable. Not on the bug rod, perfectly smooth and even every direction

I think lube that gives it a slippery feel would give the best shifting experience also. My 2 cents.

Tue Dec 19, 2023 2:12 pm

VolksRodT wrote: Hey, Ray;
Possibly a stupid Q, but do you know what the specific compound the OEM bushing was made of? & if it is known, why isn't that material used to make the re-pops? Esp if it could be inj-molded, or maybe even 3D printed? IDK, is why I'm asking. The pic of the translucent bushing looks awful thin & smooth to 'print. ???
TIA.
Marcus...

Depends on the "era".

From what I remember of the earliest VW's I worked on in high school and into college....my 411 and 412...my dads 70 and then 72 bug...and a few friends cars (buses nd type 3 mostly).....most of the handful of bushings I helped to replace were original equipment (from the factory) and dated to either the late 60's...1968-69 and early 70's through about 1973.

All of these had the same characteristic which caused them to need to be replaced. They had split and cracked or were really worn out and chattering.

Mind you they had plenty of years and miles on them so its not like we were feeling ripped off.

But they all had the same visual characteristics. They were yellowish clear...had some crusty whitish sections that looked almost like corrosion and were very hard and brittle.

They were nylon. The whitish corrosion, splitting and coming apart pretty much identifies them as Nylon 6 which fits with what the most commonly used Nylon was in the 50's through the 70's.

It is a little less brittle and less mold shrinkage so it can make more precise molded parts. Its also a little cheaper. But....it absorbs a ton of moisture which starts its breakdown and also makes it susceptible when it gets wet with dirty water from rain or the road to a peculiar protozoa that eats it.

So, by the time I got mid way through college (mid 80's) and was on my newer 412 and it needed a bushing...and other cars I worked on needed bushings....we could occasionally get OEM Nylon which would be that cream color...not yet yellowing and crusty cause its new-ish.....but that was only a couple.

Mostly what was available were slightly greasy feeling, hard, brighter white molded bushings that were either Nylon 11 or UHMW. Later I found out that sometimes they were either. The UHMW is a little softer with regard to the fact that you could leave pick and fingernail scratches in it but the nylon 11 is harder than that.

It fits because in the 70's and 80's , nylon 11 is what the automotive industry moved toward. Less moisture absorption and other good properties, cleaner appearance etc.

Later....late 80's and early 90's.....if you bought a bushing at the dealer (when they had one) it was still the harder white UHMW or Nylon 11.

If you bought one aftermarket say at Rocky Mountain motorworks or somewhere....it was typically milky white with a blue tinge around the thin edges where it was slightly translucent....indicative of polypropylene.

Now....polypropylene (PP) is a pretty damn slick, tough and very chemically inert plastic. It would be fine for these bushings....but....its not as slick as UHMW which is about 2X slicker (0.15 friction coefficient vs 0.3-0.4 for polypropylene).

But PP is a good deal softer and creeps and floes with age. They typically wore out fast. Not from the friction but from kind of getting stretched out of shape.

Then we got the strange crap in the late 90's early 2000's. I bought one from Kerr auto in OKC that was transparent aan soft but tough..urethane. Died in 6 months. I got another one to replace it at a FLAPS (pre internet and not much local)...and it was greasy and soft and milky white. It looked like basic polyethylene....and crapped out in about a year.

So.....Nylon...even the original nylon 6 would be fine (just know it will not last forever)...or Nylon 66 or Nylon 11, nylon 12 or UHMW...would all be fine.

If you could find one molded from Nylatron (nylon with 20-30% moly)....it would likely last forever.

Oh....and the reason why a lot of aftermarket "repops" do not use certain materials like nylons...is that to keep them from sticking to the molds....the molds have to be really good. Mirror polished and accurate. Its sensitive to too much and too little pressure and specific details of wall thickness and curves etc....are harder to work with. You have to get it right.

UHMW is actually compression molded. Totally different process.

The two easiest to mold are polypropylene and teh other polyethylenes like low density, medium density and high density. By the way...UHMW stands for ultra high molecular weight polyethylene.

The urethane repop I got was simply "cast"...very easy. It would have been just fine but they used the wrong hardness or durometer of urethane.

Ray