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63Avanti
12-13-2006, 02:20 PM
From my 200K+ Volvo and VW life experience, I am a fan of Delrin.
Upsides:
1. does not distort and cause other component wear
2. lasts for ever (more or less)
3. impervious to the petro chemicals that make rubber fail
4. much easier to dismount than rubber if you have to maintenance

downsides:
1. does not flex as much as rubber and you will feel it if you do not excellent shocks/struts.
2. also, due to the flex, without the better shocks, it "may" cause "more" joint wear
3. more expensive.

Based on my experiences, I have bought black delrin rods of the correct OD, and will drill them out (drill press) for the rear suspension. (Most of the rear bushings are cylindrical). Will cost about 1.50 per bushing. For the fronts, I am staying with rubber as
1. shapes are more complicated that I wish to machine right now.
2. front end harshness.
I am investigating a reasonable replacement for Avanti shocks that are tuned for euro-suspensions, which are much more stiff than US. These are Bilstein (TC), KYB, Koni. These shocks are tuned to absorb the "harshness" inherent in the delrin. If I ever find a reasonable euro-replacement, I will immediately move to Delrin all around, and never have to worry about bushings again.


Terry, North Texas
1963 Avanti R2, 63SR1065
(in stage 1 resto "Project A")
http://sterkel.org/avanti
1985 Kubota L2202(Diesel)
2000 VW Jetta GLS
1999 Toyota rice burner

Roscomacaw
12-13-2006, 04:12 PM
May I be forgiven for repeating myself:

"Prior to '53, Stude cars had ALL-METAL inner control arm bushings! And it's these pre-53 cars that garner lots of praise from their owners as to comfortable, sweet-driving machines. Hmmmmmmmmm.... So given that, what don't compute about the argument for more noise and harsness of ride?"

I've had a long talk with a vendor that sells these and has for years. He has a policy of replacing the delrin bushings with the stock rubber ones if a customer's not happy with the Delrin. He's never had to send the rubber ones out yet. That's in about 8 years or more of selling them! Nothing beats experience for establishing expertise.;)

Another point is that Studebaker actually backpedalled a bit and spec'd the 51-52 upper control arm WITH it's metal inner A-arm bushings for R3/R4 vehicles.;) I'd like historical (factory) reasoning for doing this. You'd think that if rubber bushings were good enough for the R2s, they'd be suffcient for R3/R4 work!

Another point is that the cars running in the Carrerera Panamerica are using Delrin. It's been noted that when some drivers have made inadvertent off-road excursions - if they've got rubber bushings in the A-arms, the arms suffer severe damage. With Delrin, not the case.

BTW, thanks for the tip about redrilling existing bushings for rear applications. I've been wanting to use Delrin on rear springs but none of the vendors I know of have taken to having any made. yet...

Miscreant adrift in
the BerStuda Triangle
http://images.andale.com/f2/115/106/906179/2006/12/7/truckonhill3.jpg

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe

CHAMP
12-13-2006, 05:51 PM
Sounds like Delrin is getting a bad rap from some much the way DOT-5 Silicone brake fluid has.

GARY H 2DR.SEDAN 48 STUDEBAKER CHAMPION NORTHEAST MD.

PackardV8
12-13-2006, 09:51 PM
Hi, Mr. Biggs,

Agree with you the early all metal upper inner bushings are the way to go if handling and long wear are priorities.

Cannot, however, quite follow how the delrin will do anything to protect the a-arms in an off-road excursion. Can you explain how this would work? Seems if the rigidity of delrin would cause the a-arm to bend sooner, where the rubber would give a bit before the a-arm had to bend. All explanations appreciated.

thnx, jv.

PackardV8

Roscomacaw
12-13-2006, 10:38 PM
jv, I was told that the folks that have experienced this phenomenon were baffled by it as well. But they've gone to having extra sets of Delrin-equipped A-arms in their store of spares.:)

Miscreant adrift in
the BerStuda Triangle
http://images.andale.com/f2/115/106/906179/2006/12/7/truckonhill3.jpg

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe

PackardV8
12-13-2006, 11:03 PM
Again, I apologize for not getting it, but if the delrin in some mysterious way protects against damage, why would they need lots of spares?

thnx, jv.

PackardV8

63Avanti
12-14-2006, 11:17 AM
I once took a tutorial on suspensions, with lots of dynamic math, e.g. differential calculus. Made my eyebrows hurt. What I got out of it was that "fixing" one element will have an impact somewhere else, in ride, sway, new stresses on other components, what ever.

After driving my R2, I am confident that rear can benefit from delrin with little negative affects, due to the simple geometry. in the Front, I am waiting to find that still mythical euro-tuned shock to allow me to be comfortable with delrin. This is NOT to say that I am right, it just reports my thoughts on the matter. I will happily change my mind, as I am not thrilled with my current conclusions!
cheers!


Terry, North Texas
1963 Avanti R2, 63SR1065
(in stage 1 resto "Project A")
http://sterkel.org/avanti
1985 Kubota L2202(Diesel)
2000 VW Jetta GLS
1999 Toyota rice burner

Roscomacaw
12-14-2006, 01:16 PM
jv,
From what I understood, spares are needed because damage CAN result - it's the DEGREE of damage that results that proves to be different. I didn't say that Delrin bushings made the car accident-proof or damage-proof.;)
Further, if I were racing a vintage vehicle, I'd summarily take along spares of most everything mechanical - just to be prepared.

Miscreant adrift in
the BerStuda Triangle
http://images.andale.com/f2/115/106/906179/2006/12/7/truckonhill3.jpg

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe

1949commander
12-15-2006, 08:50 AM
I can see how the metal bushings can make the control arm stronger than if it had rubber bushings. Here is why, with the steel bushings you have a threaded pivot and a threaded inner bushing. It's like a bolt and a nut. This system unitizes the control arm ends to the frame mounting brackets. With rubber bushings you have in effect a separate arm and mounting bracket. The arm must be strong enough to take the up and down force and the flex force. It makes since that most suspension components on cars when rubber was used in place of the steel bushings were made much more stout. Since Delrin is very rigid it would tend to act more like the old threaded steel bushings. Rubber bushings are tricky as well, since you have to come up with the right consistency to absorb shock without allowing the whole suspension to resonate when you hit a bump.

Restore it, don't replace it.Keep the Studebaker reproduction industry going