Front 4-bar ends.

[Zandoz]

I am trying to decide what I want to use for the frame ends of my front 4-bar set up. The setup I have is from Speedway...5" drop tube axle, Model A style spring over configuration, and stainless bars with welded on bushing loops set at 7 degrees. I'm planning on the loop ends to go on the batwings. My intent is to minimize binding and twisting on the frame...but I'd also like to minimize vibration transferred to frame. I've pretty much ruled out the conventional bushing ends due to the binding and twisting transfer. I'm trying to choose between conventional spherical rod ends, or articulated bushing ends like these


Any thoughts on which would be the best way to go?

 

[old round fart]

If the 7 degree bushing is right at the frame, I would use them. The ones you pictured gives 4 more places to fail when the nuts fall off!

 

[ellis8500]

I used heavy duty spherical rod ends for my 4-bar suspension. They work fine. Actually the front spring is so stiff that the front axle really doesn't articulate very much at all.

 

[Zandoz]

If the 7 degree bushing is right at the frame, I would use them. The ones you pictured gives 4 more places to fail when the nuts fall off!

The 7 degree bushings are welded on the ends of the bars...and will go on the batwings. The frame ends will end up at around 10 degrees. As far as the nuts falling off goes, I see that as being no more of a risk than any of the other nuts in the suspension and steering. What I am concerned with is that the whole design is sturdy enough, even though they are sold specifically as 4 bar adjusters.

 

[Zandoz]

I used heavy duty spherical rod ends for my 4-bar suspension. They work fine. Actually the front spring is so stiff that the front axle really doesn't articulate very much at all.

I'd originally planned on using sphericals, but I ran across a thread where the majority opinion was that they were questionable for street use, and that the bushing adjusters are the way to go. My thought is that the articulated bushings might be a good compromise between vibration damping and articulation <shrug>

I may not be facing a stiff spring limitation...I have a 31" mono-leaf spring.


.

 

[choppinczech]

I say go for it. I've seen those bushings. They're quality made.

 

[ellis8500]

I'd originally planned on using sphericals, but I ran across a thread where the majority opinion was that they were questionable for street use,

I'm curious about what would make them questionable. I had not heard that. I have heard of clevises breaking but not properly sized, quality spherical rod ends. Perhaps some out there can educate me about this. Need scientific facts please.

 

[Zandoz]

I'm curious about what would make them questionable. I had not heard that. I have heard of clevises breaking but not properly sized, quality spherical rod ends. Perhaps some out there can educate me about this. Need scientific facts please.

It wasn't that there was a problem with them, it was that they are of less of an advantage on the the street than the vibration damping of the bushing ends.

 

[T-Test]

It wasn't that there was a problem with them, it was that they are of less of an advantage on the the street than the vibration damping of the bushing ends.

In these little cars you are counting on the ride wayyyy too much. Build it safe FIRST, then worry about the looks or ride later. Ted Brown is the best man to explain it to us, which I thought there was an article on in the tech pages. I'll look and see.

 

[Zandoz]

In these little cars you are counting on the ride wayyyy too much. Build it safe FIRST, then worry about the looks or ride later. Ted Brown is the best man to explain it to us, which I thought there was an article on in the tech pages. I'll look and see.

Safety is always first...which is why I'm questioning the wisdom of going with the articulated bushings. I've never seen them in use, and do not know how safe they are.

I know these buggy spring suspensions will never give a great ride. In my mind, when it's not detrimental to safety, there is no reason not to make the ride as well as possible. Since mine is going to be a short wheelbase car it's going to need all the help it can get.

If I remember correctly, Ted advocates the conventional bushing ends over the sphericals...but I don't recall seeing anything from him on these articulated bushings. But my memory is like trying to use a chain link fence to catch air

 

[ellis8500]

I doubt, but really do not know, that the type of rod end is going to affect the ride in such a manner that you would notice it. A hairpin radius rod usually uses a heim on the frame end and clevises at the bat wings. A clevis is prone to fail if there is any misalignment between the bat wing and hairpin angles. Heim joints are self aligning so this does not present a problem. The reason the ride seems so stiff is due to the very light supported weight of the car. When you subtract the tires and axles from the total weight there is not much left at each wheel so there is very little dampening due to vehicle weight. An impulse force from a road bump produces a high acceleration rate [A=F/M]. The rod end design will not change those facts. You will find that many of the roads you think are smooth.....are not.

 

[ellis8500]

Take a look at Midwest Controls for a variety of rod ends. I use the MXM series. High strength chrome-moly body with nylon bearing race. These are self-cleaning and have high load capacity.

 

[Zandoz]

Take a look at Midwest Controls for a variety of rod ends. I use the MXM series. High strength chrome-moly body with nylon bearing race. These are self-cleaning and have high load capacity.

It looks like I'd want the MXM-10-8 version. They definitely have the price advantage. How long have you been running them?

 

[ellis8500]

I've got about 700 miles on the car.

 

[fluidfloyd]

I am trying to decide what I want to use for the frame ends of my front 4-bar set up. The setup I have is from Speedway...5" drop tube axle, Model A style spring over configuration, and stainless bars with welded on bushing loops set at 7 degrees. I'm planning on the loop ends to go on the batwings. My intent is to minimize binding and twisting on the frame...but I'd also like to minimize vibration transferred to frame. I've pretty much ruled out the conventional bushing ends due to the binding and twisting transfer. I'm trying to choose between conventional spherical rod ends, or articulated bushing ends like these
View attachment 10953

Any thoughts on which would be the best way to go?

Bill...Sense you have asked I will give you my thoughts on the subject of articulated bushings compared to spherical rodend bearings. From looking at the attached photo of the articulated bushing unit I see one main issue to my thinking. As you stated you will be running a parallel 4 bar front suspension system. That particular design will not only move in the vertical axis but will also twist in the horizontal axis front to rear as the chassis rolling turns etc. That articulated bushing is not a bearing and will be metal to metal that will try to twist. I think what will actually happen is you will continually back the jam nuts off over time and travel. I do know a lot of chassis shops that won't even use the polyurethane P&J style bushings for that very reason. The true rodend bearing such as Midway and others will allow complete articulation freedom without any binding or frictional problems. As to wear and tear on those type bearings...Use good ones. Look at the ratings and get one with a Teflon or like liner that continually wipes or cleans itself. Use Milspec jame nuts that have a Class 3 thread. No nuts from Graingers, Fastenal, or the hardware store. Lots of off shore stuff out there and not that much cheaper. If in doubt ask them the manufactures name and location. Do the wobble test. Screw on one to the rodend shank midways and see if it wobbles. If it does toss it. As for safety concerns of rodends. Look at the aircraft industry. The are used in everything from control linkage to landing gear. Helicopters use them through out the rotor head and tail rotor control systems. Just use "Good Ones."

While I'm on the subject I want to comment on the fixed style of polyurethane rodend style of bushings. Polyurethane is a non compressible material. You can squeeze it, twist it and flex it but you can not compress it. If you put a piece under your shop press it will flatten out but it is not compressing. It is flowing in the path of least resistance. It makes an excellent receiver to press parts into with a male die. You build a receiver box that restrains the material from flowing away from the male die. You then machine a trough below the receiver box that will allow the material to receive that flowing material. Once you raise the die and your part the material will return to it's original shape. For this reason it really makes a lousy suspension bushing as it does no noticeable dampening of road noise or vibration. It also doesn't like to twist length wise along the trough bolt holding it to the chassis. It wants to flex single shear bolts as they see road hole impacts. Even in the rotational axis as the suspension goes up and down it will squeak from friction requiring a pre lube grease. Years ago I talked to the engineers at one of the manufactures about using it in place of machining a female receiver die. He told me to think of polyurethane as a solid hydraulic oil. You can't compress it but it will flow to where you direct it. Now before I get hammered by everyone here that has these type bushings I'm putting out my experience and opinion but just go do your own research and you will see the short comings of this material. That is why Ted Brown was such a big fan of OM style rubber bushing with bonded steel housings and sleeves. They will compress and give you the dampening qualities you are looking for. The original P&J catalog sold the rodend housing with a Vega rubber bushing pressed in. Change in my opinion was cost related in the large quantity they were dealing with.

Bill, the bottom line is the same for whatever you chose. Quality and articulation freedom. Several ways to get there so take your choice. I am a believer in the rodend method. We use them in the street Scarab be build and to my knowledge no one has requested a replacement bearing since 2006 when we started. Hope this will be of some help to you. Good Luck with your project.

George

 

[fletcherson]

Bill...Sense you have asked I will give you my thoughts on the subject of articulated bushings compared to spherical rodend bearings. From looking at the attached photo of the articulated bushing unit I see one main issue to my thinking. As you stated you will be running a parallel 4 bar front suspension system. That particular design will not only move in the vertical axis but will also twist in the horizontal axis front to rear as the chassis rolling turns etc. That articulated bushing is not a bearing and will be metal to metal that will try to twist. I think what will actually happen is you will continually back the jam nuts off over time and travel. I do know a lot of chassis shops that won't even use the polyurethane P&J style bushings for that very reason. The true rodend bearing such as Midway and others will allow complete articulation freedom without any binding or frictional problems. As to wear and tear on those type bearings...Use good ones. Look at the ratings and get one with a Teflon or like liner that continually wipes or cleans itself. Use Milspec jame nuts that have a Class 3 thread. No nuts from Graingers, Fastenal, or the hardware store. Lots of off shore stuff out there and not that much cheaper. If in doubt ask them the manufactures name and location. Do the wobble test. Screw on one to the rodend shank midways and see if it wobbles. If it does toss it. As for safety concerns of rodends. Look at the aircraft industry. The are used in everything from control linkage to landing gear. Helicopters use them through out the rotor head and tail rotor control systems. Just use "Good Ones."

While I'm on the subject I want to comment on the fixed style of polyurethane rodend style of bushings. Polyurethane is a non compressible material. You can squeeze it, twist it and flex it but you can not compress it. If you put a piece under your shop press it will flatten out but it is not compressing. It is flowing in the path of least resistance. It makes an excellent receiver to press parts into with a male die. You build a receiver box that restrains the material from flowing away from the male die. You then machine a trough below the receiver box that will allow the material to receive that flowing material. Once you raise the die and your part the material will return to it's original shape. For this reason it really makes a lousy suspension bushing as it does no noticeable dampening of road noise or vibration. It also doesn't like to twist length wise along the trough bolt holding it to the chassis. It wants to flex single shear bolts as they see road hole impacts. Even in the rotational axis as the suspension goes up and down it will squeak from friction requiring a pre lube grease. Years ago I talked to the engineers at one of the manufactures about using it in place of machining a female receiver die. He told me to think of polyurethane as a solid hydraulic oil. You can't compress it but it will flow to where you direct it. Now before I get hammered by everyone here that has these type bushings I'm putting out my experience and opinion but just go do your own research and you will see the short comings of this material. That is why Ted Brown was such a big fan of OM style rubber bushing with bonded steel housings and sleeves. They will compress and give you the dampening qualities you are looking for. The original P&J catalog sold the rodend housing with a Vega rubber bushing pressed in. Change in my opinion was cost related in the large quantity they were dealing with.

Bill, the bottom line is the same for whatever you chose. Quality and articulation freedom. Several ways to get there so take your choice. I am a believer in the rodend method. We use them in the street Scarab be build and to my knowledge no one has requested a replacement bearing since 2006 when we started. Hope this will be of some help to you. Good Luck with your project.

George

I can attest to eurothane bushings being stiff and noisy, they do work well to stiffen a soft suspension, like sway bar bushings, etc, but they are loud and transfer vibration, noise, from my experience in street cars. I can appreciate trying to get the best ride and handling quality, but I would be very concerned with using quality connectors that will not allow any slop, sloppy joints can lead to unstable and poor handling, which is in my opinion, much worse than some harshness, if that's a word.

 

[Zandoz]

Bill...Sense you have asked I will give you my thoughts on the subject of articulated bushings compared to spherical rodend bearings. From looking at the attached photo of the articulated bushing unit I see one main issue to my thinking. As you stated you will be running a parallel 4 bar front suspension system. That particular design will not only move in the vertical axis but will also twist in the horizontal axis front to rear as the chassis rolling turns etc. That articulated bushing is not a bearing and will be metal to metal that will try to twist. I think what will actually happen is you will continually back the jam nuts off over time and travel. I do know a lot of chassis shops that won't even use the polyurethane P&J style bushings for that very reason. The true rodend bearing such as Midway and others will allow complete articulation freedom without any binding or frictional problems. As to wear and tear on those type bearings...Use good ones. Look at the ratings and get one with a Teflon or like liner that continually wipes or cleans itself. Use Milspec jame nuts that have a Class 3 thread. No nuts from Graingers, Fastenal, or the hardware store. Lots of off shore stuff out there and not that much cheaper. If in doubt ask them the manufactures name and location. Do the wobble test. Screw on one to the rodend shank midways and see if it wobbles. If it does toss it. As for safety concerns of rodends. Look at the aircraft industry. The are used in everything from control linkage to landing gear. Helicopters use them through out the rotor head and tail rotor control systems. Just use "Good Ones."

Well, it looks like I'm back to my original plan...using the sphericals. I'm leaning towards these
http://www.speedwaymotors.com/Chromoly-Heim-Joint-Rod-Ends-5-8-18-RH-Male-1-2-Inch-Hole,28462.html
over these from Midwest
http://www.midwestcontrol.com/part.php?id=2035
because to my uninformed opinion, the Kevlar/Teflon race seems better than nylon <shrug>

While I'm on the subject I want to comment on the fixed style of polyurethane rodend style of bushings. Polyurethane is a non compressible material. You can squeeze it, twist it and flex it but you can not compress it. If you put a piece under your shop press it will flatten out but it is not compressing. It is flowing in the path of least resistance. It makes an excellent receiver to press parts into with a male die. You build a receiver box that restrains the material from flowing away from the male die. You then machine a trough below the receiver box that will allow the material to receive that flowing material. Once you raise the die and your part the material will return to it's original shape. For this reason it really makes a lousy suspension bushing as it does no noticeable dampening of road noise or vibration. It also doesn't like to twist length wise along the trough bolt holding it to the chassis. It wants to flex single shear bolts as they see road hole impacts. Even in the rotational axis as the suspension goes up and down it will squeak from friction requiring a pre lube grease. Years ago I talked to the engineers at one of the manufactures about using it in place of machining a female receiver die. He told me to think of polyurethane as a solid hydraulic oil. You can't compress it but it will flow to where you direct it. Now before I get hammered by everyone here that has these type bushings I'm putting out my experience and opinion but just go do your own research and you will see the short comings of this material. That is why Ted Brown was such a big fan of OM style rubber bushing with bonded steel housings and sleeves. They will compress and give you the dampening qualities you are looking for. The original P&J catalog sold the rodend housing with a Vega rubber bushing pressed in. Change in my opinion was cost related in the large quantity they were dealing with.

Bill, the bottom line is the same for whatever you chose. Quality and articulation freedom. Several ways to get there so take your choice. I am a believer in the rodend method. We use them in the street Scarab be build and to my knowledge no one has requested a replacement bearing since 2006 when we started. Hope this will be of some help to you. Good Luck with your project.

George

I can attest to eurothane bushings being stiff and noisy, they do work well to stiffen a soft suspension, like sway bar bushings, etc, but they are loud and transfer vibration, noise, from my experience in street cars. I can appreciate trying to get the best ride and handling quality, but I would be very concerned with using quality connectors that will not allow any slop, sloppy joints can lead to unstable and poor handling, which is in my opinion, much worse than some harshness, if that's a word.

I'm having problems finding bushings that are some kind of happy medium for the axle ends of the Fox Body rear control arms. Everything I've found is either eurothane or OEM rubber. Yesterday I finally gave up and ordered the eurothane bushings for the lower control arms. I'll probably go with the OEM rubber on the uppers, to get a bit less binding and a bit more vibration damping. The frame ends of all 4 control arms will be 2" Johnny Joints.

 

[ellis8500]

I also looked at Speedway; but, they do not show load rating nor country of origin. The Midwest bearings are all made in US and they show load rating. For the MXM-10-8 it's 14,356 max static load. The only way we would see that much load on our radius rods is if we hit something that doesn't move much. Of course, then, lots of other things would bend and break. Also, they are less than half the price of the Speedway bearing you listed. It's your choice.

 

[fluidfloyd]

I'm having problems finding bushings that are some kind of happy medium for the axle ends of the Fox Body rear control arms. Everything I've found is either eurothane or OEM rubber. Yesterday I finally gave up and ordered the eurothane bushings for the lower control arms. I'll probably go with the OEM rubber on the uppers, to get a bit less binding and a bit more vibration damping. The frame ends of all 4 control arms will be 2" Johnny Joints.

Bill...That is a very good solution for your rear suspension. Smart thinking for sure!


George

 

[fluidfloyd]

I also looked at Speedway; but, they do not show load rating nor country of origin. The Midwest bearings are all made in US and they show load rating. For the MXM-10-8 it's 14,356 max static load. The only way we would see that much load on our radius rods is if we hit something that doesn't move much. Of course, then, lots of other things would bend and break. Also, they are less than half the price of the Speedway bearing you listed. It's your choice.

Bill... We use the Midwest bearings in our production Scarabs and have had no problems with wear or slop issues. These cars are around 2100-2200lbs wet and are driven hard with some seeing some road racing time at speed. There are several other brands out there that are equal in quality but I would never buy one from an unknown manufacturer. That is one thing I dislike about the Midwest units. They have zero markings indicating what you actually have. As long as you buy direct you would be good but if through a retail speed shop you only have their word and that's not good enough for me in critical parts. Just takes a little home work.

George