ball bearing lower control arm bushing

[diffdude]

What do you guys think of these ball bearing LCA bushings? I bought them from coleman racing.There steel outer and inner with a sealed ball bearing in the middle (kind of looks like a small 9 inch axle bearing). I'm going to put them in as soon as the ups man brings my sc&c upper arms. I have poly in there now so i will post if there is any differents.
https://static1.pt-content.com/images/noimg.gif

[Derek69SS]

Sweet :cool: Are they any cheaper than Delrin bushings?

[diffdude]

they list for 69.00 a side.

[CarlC]

Is it a ball bearing or a spherical plain type? A ball bearing will have a very low load capacity. Also, since there is very little rotation a ball bearing likely won't last long.

[diffdude]

It's a sealed ball bearing there are 2 in each bushing. As far wear I will have to see, they are used in round-e-round cars so I hope they have tested them.

[parsonsj]

I'm using needle bearings for my upper control arm bushings. I got 'em from Lefthander Chassis' ASA upper control arms. Brian Schein took that design, figured out the bearing numbers, upsized them accordingly, and make his lower control arm bushings with needle bearings.

They also use thrust washers to minimize binding under heavy braking.

jp

[Skip Fix]

There is a circle track company that makes them with sphericals that you weld in the LCA.

[element180]

Reminds me of the Guldstrand roller bearing conversion

http://www.guldstrand.com/roll.htm

[CarlC]

There's a big difference between a ball and a needle roller bearing.

Personally, I would not consider a ball type.

[B Schein]

Like John said I used roller and thrust bearings in place of all my bushings I got the upper stuff from John ( thanks John ) and bought the stuff for the lowers from MSC it was pretty expensive though at $300 for just the lowers. I hope works as good as it looks.

[Matt@RFR]

Off topic, but Brian, who built your control arms? That welded "bend" is scary. If that thing was engineered to be made out of 4130, I hope whoever the engineer was took the giant and abrupt HAZ in to account.

You should put a gusset there, bare minimum.

[chicane67]

Single shear is pretty scary.........

[B Schein]

I am going to remake the lowers with a biger size tubing that I can bend Katz called for 1-3/8 I couldnt find a die any where to bend it. so I just did that to get the car back on the ground plus I already had the tubing. There is also a large web that goes on the bottom arm. Both front and back shoulder bolts will be in double shear I just havent got to that yet notice the lack of coil overs or any thing else.

[Norm Peterson]

I hope that the additional bracing includes something in the vertical direction at least for the rear pivots. I wouldn't care to rely solely on the cantilever bending stiffness/strength of two (or three) small tubes. I'm assuming that the coilovers will be mounted on the LCAs somewhere inboard of the balljoints.

Do you have some idea as to how rigid the bracketry for the rear pivots is/will be in the various directions? They are the ones that will be seeing most of the fore/aft loads from bumps and braking, and any deflection back there will show up as compliance steer (similar to bumpsteer). I'm thinking toe-in as the rear pivots are pushed in laterally toward the car centerline, and a mild tendency to "loosen" the handling.


Norm

[B Schein]

I haven’t really worked oh the suspension for over year I have been busy doing body and going to school full time. I have remodeled (Katz used solid works and pro-e doesn’t analyses things well when they are iges files, they have know volume) the whole thing in pro-e and plane on doing some load analysis after I take my finite element analyses class this semester. Then I will design the double sheer brackets as well as bracing for the upper control arm plates and address any other issues. Maybe I shouldn’t have put up any more pictures until I am done but that won’t be until around some time late 2008.

[TitoJones]

There's a big difference between a ball and a needle roller bearing.

Personally, I would not consider a ball type.

Like you know anything about bearings. Whatever. ;)

Tyler

[Mean 69]

I'm curious why you'd want to use anything other than the plastic/nylon type bushings that Global West and DSE/others sell? In this location, it's a great solution, and well proven. If not that, why not just use a suitable rod end? I can see that this would make fabrication easier if using an existing bushing style control arm, but it's hard to beat the nylon type deals in my opinion.

Mark

[Marcus SC&C]

Jaguar used needle bearings in the lower arms of the IRS for years. It was problematic because the arms didn`t travel enough degrees for the needles to wear evenly. They`d flat spot,get sticky and loose. They now sell regular bushing conversions for them. There`s nothing new under the sun. ;) Mark SC&C

[Norm Peterson]

. . . Maybe I shouldn’t have put up any more pictures until I am done but that won’t be until around some time late 2008.I'd say that that was precisely something to NOT be second-guessing yourself about. What they have done is prompt a number of useful comments that should be taken at face value rather than as personally-directed commentary. IOW, free hints.

Re: analysis, some less complex structural 3-D space frame analysis software such as STRUDL can analyze that well enough to provide stiffnesses, and a small pipe stress analysis software would probably be able to generate better estimates of the stresses at tube welds.


Norm
(pipe stress/support engineer this year)

[CarlC]

Jaguar used needle bearings in the lower arms of the IRS for years. It was problematic because the arms didn`t travel enough degrees for the needles to wear evenly. They`d flat spot,get sticky and loose. They now sell regular bushing conversions for them. There`s nothing new under the sun. ;) Mark SC&C

Exactly.

The point loading of a ball bearing makes things much worse. As far as companies hopefully testing and engineering a product, there usually a lot more hope than engineering involved.

For low-speed, low-rotation, highly-loaded rotational members some type of a bushing is almost always preferable.

Tyler,

Yeah, that's me, knowing way too much about something that 99% of people most of the time couldn't care less about! :hammer:

[parsonsj]

Maybe I shouldn’t have put up any more pictures until I am done but that won’t be until around some time late 2008.Nah, you should listen to what these guys have to say. Most of them :) know their stuff. That's what engineering is mostly about: criticism that can make your product better.

Anyway, I realize that needle bearings are best at complete rotational loads, but let's remember how driveshaft u-joints are made. The needle bearing should also reduce friction-binding where the sideways forces deflect the nylon/delrin bushings and cause binding, especially during braking. Proper lubrication, and close inspection will certainly be needed to see how this pans out.

jp