Front Axle / Front Suspension: Delrin control arm bushings ?

[wkwayland]

I have a 1962 GT Hawk that I will be replacing the control arm bushings next month. I was wondering if anyone has used the Delrin bushings and what there experience has been with them in relation to OEM bushings? Are they harder or easier to install? Noise, vibration or binding issues? Just wanted some opinions. Thanks Weymouth

[Alan]

They are easier to install than the stock jacketed rubber. They last longer. They have a few idiosyncrasies. They need silicone grease, you will have to grease them yourself to make sure they are done right. And they transfer more noise to the frame and body. Plus they ride a little harder. If done right they will last a long time.

[bensherb]

Alan, are the Delrin bushings they sell for the front bushed internally with a steel sleeve that the bolt tightens down on? From pics in catalogs it doesn't appear so.

I made Delrin bushings and new shackles to replace all the junk stock rear spring and shackle bushings. The design of the stock shackle bushings is bad offering no lateral support and allowing the rear of the springs, and consequently the axle to shift sideways. It no longer can with my bushings. They have 1 1/2" of bearing area at each shackle contact point, and the bushings themselves have an internal steel sleeve they rotate on which the shackles tighten dawn against. It works great, no more rear axle sideways movement and I haven't noticed any appreciable difference in transferred noise or harshness in ride over the stock stuff.

[StudeRich]

Neat idea, did you test these out on the long wheelbase '62 GT Hawk you own or something else?

I was thinking those look very durable, but could ride a bit harsh on a 109" Wheelbase '64 Daytona Hardtop.

[dynolou2]

Where did you get the materials that built the bushings out of ? Are you willing to produce more? I do have a mini lathe at home. thanks Lou Cote

[doofus]

Delrin will out last regular bushings but will give a harsher ride, BTDT. Luck Doofus

[sweetolbob]

Where did you get the materials that built the bushings out of ? Are you willing to produce more? I do have a mini lathe at home. thanks Lou Cote

Just use Ebay or Google Delrin Rod Stock. You'll find it generally available. Most of mine comes from Ebay. I think a number of places sell their shorts at very reasonable prices Ebay to recover some raw material costs. It's way less than the commercial places.

It cuts as well or better than UHDPE so sharp tooling on your mini should work fine as long as the chuck has the capacity and depth to hold the stock.

Bob

[Skybolt]

My take on the rear Delrin.

Here are the Delrin rear shackle bushings I have been using. I have used these before on a Cruiser and I have a few comments. There is no steel inner. The bolt has been drilled for a grease zerk and has smaller holes to allow for internal lubrication. The inner of the bushing has been rifled for lubrication.

The problem with holding the shackles from moving is that they were designed to allow the rear axle to remain in contact with the ground and allow some body roll/weight transfer. What happens if the shackles are held rigid is the springs start to want to slide within the spring pack. Spherical bushing were designed for the front in some applications to alleviate this. The only other way around this I have seen is to introduce a Panhard bar. This I will be doing as I have already seen the aforementioned movement inside the spring pack.

Just some thoughts.

Len

[wkwayland]

Thanks, everybody. A lot of very useful information. Now to decide how I want to go on the front control arms. I noticed that the rear axle does jump around a lot, actually my 85 year old father is the one that mentioned that. Thanks, again. Weymouth

[Skybolt]

Just another note I forgot to add to my other post.

The springs work best when the ends are parallel withe the axle mounting. Hence the rubber bushings to allow this to happen during the work the spring do. Holding the rear shackle and front of the spring ridged introduces a twist in the spring when the axle tries to stay planted parallel with the ground. This twisting of the springs hinders the operation and performance of the design of the spring pack. It is no longer just working up and down. It has been a problem discussed and worked on for years in road racing. We are working on an inferior design but it is adequate for everyday use. It is when we start modifying for performance we encounter the limitations. Keeping this in mind we can make it work in most situations, although not as well as some better designs. I don't believe most Studebaker drivers with find the limits to the aforementioned problems but some, such as myself have.


Len

[Buzzard]

I personally take responsibility in ruining the ride quality of many cars. We had a high performance shop so we modified lots of cars. I'm now old enough to desire some decent level of comfort rather than balls out response and handling. My main example was my '72 Hurst Olds Indy Pace Car Convertible. I replaced ALL the bushings with Energy Suspension Urethane components in the effort to achieve the best handling "A" Body GM ever had. Man did it ride harshly on the street (with Bilstein shocks and huge sway bars) BUT was very capable in an autocross slalom event. The result was unbelievable handling from such an old chassis design but with a tricked High Effort, fast ratio steering box and fat tires it achieved superb control and g-forces which made it a star in parking lot events.
Another one I couldn't leave alone was a 1986 Olds Vista Cruiser Wagon done up with a HP 403, big sway bars etc.& enormous 17" fat HP rubber. With the urethane in the the rear control arms, there was so little deflection left, that it tore the mounts out of of the rear control arms and cracked them in half as I had used a 1 1/2" sway bar front and rear. As once said, everything is a compromise. Good luck with your choices.
Bill

[Alan]

Ben, The Delrin do not have a sleeve. For the rear I use UHMW with a stainless sleeve.

[bensherb]

Neat idea, did you test these out on the long wheelbase '62 GT Hawk you own or something else?

I was thinking those look very durable, but could ride a bit harsh on a 109" Wheelbase '64 Daytona Hardtop.

Yes they're on my '62 GT Hawk. I think the reason they don't ride obviously rougher is because with the stock pieces the outer steel sleeve and the inner one with the rubber under so much pressure between them, there's VERY little rubber in there and it's really hard, so it doesn't do much to absorb vibration.

I don't like the idea of using the retaining bolt as a bearing surface and needing to leave it "just a bit loose" so things will be able to move, it defeats the purpose. Hence the inner bearing sleeve in the Delrin. I bought extra to make them for the front when needed but the front was rebuilt with new stock stuff shortly before I got the car so it will be a while.

For a source for Delrin, check around for a local company who works with plastic, they often have scraps or shorts the'll sell cheap. That's where I got mine everyplace I found online, including Ebay was too expensive.

If it'll fit in you small lathe you can cut it. It works like butter, just don't get it hot. Plastics change size a lot with temp, to maintain a tolerance, work and measure it cool. I made the inner sleeves from 5/8" bar, turned and polished to 9/16" and bored for the 7/16" bolt. They were more work than the Delrin. I kept tolerances tight .001"-.003" sleeve to bushing, and +.010 -.000 on sleeve length. I wanted the bolt to tighten against the sleeve not the bushing.

[Skybolt]

I don't like the idea of using the retaining bolt as a bearing surface and needing to leave it "just a bit loose" so things will be able to move, it defeats the purpose.

How does the bushing get lubricated, between the rotating surface?

Len

[56GH]

I machined up the Delrin bushings for both rear springs on my former 1953 Champion coupe. No sleeves, just plain bushings the same length as the steel-rubber-steel originals. No lube, nothing. They lasted for years and are probably still going! Delrin is tough! And yes, the ride is slightly harsher.

Had some extra rear bushings and used them (after shortening slightly) on my later Hawk front sway bar on my 56J too. Same diameter. See 56J Only Newsletter #80 for February 2014 for details.