PST delrin bushed upper control arms ?Greasable pivot bush ?

just doing a little homework .
Has anyone used the PST upper control arms with Delrin bushes ? Or their greaseable lower arm pivot bush ?
Good , bad or indifferent ?
Wear ok ?
I drive my Plymouth daily and drag race monthly .
Freer upper bushes and maybe a little more caster wont hurt .
I don't want to run rod end type arms

Thanks ,

Tex

I can only say that Delrin is good stuff. It's in the Roto-Joints in the UMI UCAs on our GTO.

Delrin is an engineering plastic similar to nylon or acetal.

It is moderately self-lubricating.

The most common application I can think of, believe it or not- is model train freight car trucks.

They can take a sharply pointed metal axle turning in them for decades without perceivable wear.

The downside is if you break it, it will not glue or even really heat/weld back together.

...and that's what I know about Delrin.

thanks guys
Biomedguy , I have fitted the umi joints in a mates Chevelle . not huge mileage but seem ok
YY1 , thanks
I was hoping for a little more feedback , must not be so popular ? Will have to see how they go on my wishlist , $ conversion and freight is a killer

Tex

Tex, I can't comment as I will be looking for the same thing soon. All I can say is they look good and I think for street they have to be better than the that eye joint thing.

Thanks Bearman . Yes i really dont want heim joints on a daily .
Cant get feed back from anywhere so everyone must use heims or stock .
I found Bergman do a delrin lower control arm bush , so that is also a possibility

Tex

Anything got to be better than the heim joints. Bio put up a pic of his and it has a grease zerk on it. That's why I'm looking at those type.

I wish umi did those for mopars . I think having a grease point would be best .. Bergman doesnt use greaseable lca . And recommends the qa1 upper arms , they are poly bush and greaseable

Tex

If I can service the bushing I'm good. I see the poly and all the rest of them on heavy haul etc and I know I'm talking apples and oranges but with all the movement these things take I want something that can be serviced. The heim work fine for awhile but then wear out. I have even used heim greaseable ones and still wear out to fast. So a bushing style or back to stock for me. Dvw and I believe malex both run stock parts up front and they lift the fronts off the ground. So that says some good about the stock stuff.

bearman said:

Bio put up a pic of his and it has a grease zerk on it. That's why I'm looking at those type

Click to expand...

Yes, I also sprung for the "special" kind of grease they offer. I'm sure it can be sourced elsewhere, but I was having a shop do the installation, and I knew if they had the grease with my parts, there was no doubt they would use it.
It's a 4x4 suspension shop, but they do everything, and I'm going to have them do the complete QA1 K-member and front suspension system and my Wilwood 4 wheel disc brakes, hopefully in January

Tex did you decide on what your going to use yet.

Re Delrin plastic...
What Is Delrin?
Delrin plastic is an acetal homopolymer. Like acetal copolymer, it is a great option to replace metal and is almost like a bridge between the world of metals and the world of plastics. It is slightly stronger and stiffer than acetal copolymer, and a higher tensile and impact strength at room temperature conditions. It has one flaw, and that is a lower density center when used in larger components.

Which Is Better?
In almost every application, Delrin plastic and acetal are interchangeable. They have similar properties that do not make much of an impact in most applications. Both products are quite slippery with a low coefficient of friction. Both are excellent when used to create bearings, and because they work well in wet environments they are often used in valve components. However, the centerline porosity, that thinner center found in Delrin, can be a problem, compromising the structural integrity of the sheet or rod slightly.

Because of this porosity, Delrin can absorb bacteria and is not usable for food processing applications. It may also allow the leakage of fluids and gas. Acetal does not have these concerns. That said, for applications beyond these, Delrin is a great choice, and it has more rigidity and tensile strength.

Determining whether Delrin or Acetal is the right material for your next project is not always easy, but the team at Piedmont Plastics is ready to help. Our sales professionals can guide you toward the products that will make your next project a success, helping you to understand the differences between these two products and how those differences will impact your final product.
Exerpted from Piedmont plastics files. Looks like good material for suspension bushings etc.
BOB RENTON

bearman said:

Tex did you decide on what your going to use yet.

Click to expand...

Still in info stage . I cant find anyone who has used the pst arms nor the Bergman lca bushes . It seems to use the Bergman lca bush they recommend using an adjustable heim joint strut rod , more expence . I am leaning towards the greaseable QA1 upper arm , but i would want to be able to buy replaceable bushes before purchasing . I guess i will wait and see .

Tex

I be following along the brings a nice study to the table about the delrin bushing. I'm leaning towards them. But not rushing

Tex013 said:

just doing a little homework .
Has anyone used the PST upper control arms with Delrin bushes ? Or their greaseable lower arm pivot bush ?
Good , bad or indifferent ?
Wear ok ?
I drive my Plymouth daily and drag race monthly .
Freer upper bushes and maybe a little more caster wont hurt .
I don't want to run rod end type arms

Thanks ,

Tex

Click to expand...

Hey! I wanted to contribute here. I've installed the PST upper arms in my 69 charger, and after about a year of daily driving in Seattle, here's my report:


Short answer:
They're good, they squeak when wet, and you may need to modify the mounting brackets for proper install.

Long answer:
PST doesn't mention that you will need to modify the upper a arm brackets as they may/will interfere with the tube arm and prevent the proper camber settings (see in my attached picture) When i asked them about this, they said that sometimes this is an issue (would have been nice to read that on the website before ordering so i could plan for it).

The ball joints included are of unknown quality. They're still good after a year, as are the lower ones i got at the same time, BUT all 4 of the tie rod ends and the idler arm i got from PST at the same time have failed, so who knows about the other items with ball joints in them.

I do like the design of the arm, with the extra caster built in, and it certainly seems stout. One of the grease boots was bent a little and didn't sit properly which i didn't notice until i had them in the car. (See my attached picture of the boot with car sitting on the ground)

The DELRIN bushings squeak really loudly, like the styrofoam my stereo came in, when it rains. Luckily it rained the day after I got the alignment done on the new arms and i brought it back in, squeaking like a stage coach, and my local shop (Tru Line in Seattle) put zerk fittings on both sides for me. They did note that in a perfect world, they would also pull the bushings and carve channels in so the grease would have several places to go, but as done it did quiet down almost totally after they installed the zerks. The next day it was silent. I would argue that an even more perfect world would have PST design these with zerks and channels from the get go! Tru Line did say that they like DELRIN and it should last for a LONG time.

One remaining question mark for me is, can I replace these bushings with standard rubber or poly or even new DELRIN later on if needed. So if PST wants to chime in with that info that would be great.

Final thoughts:
PST is not perfect.
I went through several unanswered emails about the grease boot i mentioned above and some of their torsion bar adjusters (which stripped when adjusting with wheels in the air, leaving me to spend 2 hours air chiseling the broken bolts out to be able to put my original Chrysler bolts and adjusters back in, see attached pictures). They did send me replacement adjusters and bolts, and the replacement grease boot, but I'm dubious about using their stuff in the future. I see that most people on this forum have had a good experience with them so it's always possible that i was just really unlucky! Their 1.03" torsion bars seem great after 9 months or so, so maybe all the ball joints will last for years. We shall see.

Hope this helps and I'd love to hear anyone else who's used these arms report on their experience!!


Ben

Wolf ,
Thanks for your input . I am still on the edge of going there . I am redoing my main transmisson at the moment . It also annoys me the sometimes lack of full clarity in possible issues on use of parts . Being on the other side of the world this becomes more than a pain in the arse .

Tex

I used the PST upper arms on my 68 charger. I had to do some minor grinding in order to make them not hit the frame at full drop. No 2 cars are the same so what fitting is required will be different on each car. That said if I was ordering upper control arms again I would go with these ones as they have extended length built into them to mitigate the contact issue.
http://www.firmfeel.com/b_body_mopar_upper_control_arms.html