Rod End Bearing Advice Request

[Jay Gadsby]

I'm looking to refresh the suspension on my Southern GT40.

Rod end bearings.

Is there a "go to" brand / brands that are popular?

The load spec - is sometimes in newtons, sometimes lbs.

Again, is there a minimum / ideal spec that you look for given the wide variation in products available?

Thanks

 

[Darius Rudis]

Bought most of mine thru SummitRacing, based on specs.
This is the rebuilt:

Before/After:

 

[Mark H.]

Have had good luck with RodEnd Supply. It's all they do.

 

[JP Verweij]

In the UK

The Rod End Bearing Specialists | Rod End Bearings

Leading supplier of rod end bearing products. Rod End Bearings have a huge range of high-quality engineering products. Get in touch today!

rodendbearing.co.uk

Rodends

Rodends and spherical bearings specialist for Industrial, Motorsport and Karting

rodends.co.uk

 

[Randy V]

One of the biggest problems I’ve seen with racecar suspension in street driven cars is lack of maintenance. They need to be cleaned, lubed and exercised through their full range of motion quite frequently. Face it - in a racing car, they’d be inspected etc at least every 500 miles or sooner.
Second biggest problem is the bolts they are interfacing with. Properly sized “shouldered” bolts so the, rod end doesn’t hammer back and forth on the bolt (those shocks are terribly hard on the rod end…
—
That said - choose carefully as the best price is rarely the best value…

 

[Neil]

Bought most of mine thru SummitRacing, based on specs.
This is the rebuilt:
View attachment 141752

View attachment 141753

Before/After:
View attachment 141754

There are some aerospace- grade spherical rod end bearing manufacturers but those are REALLY expensive. There are suppliers that can provide Teflon- lined bearings and those are usually high quality. Chrome- moly rod ends are preferred due to their higher strength. Be aware that some rod ends have a different bore size from their threaded end. Two comments re: the first photo of the blue suspension arm. 1. There are not enough threads showing on that nut. Two complete threads should show when the nut is fully torqued. 2. If this a-arm is right-side up, reverse the bolt. This way if the nut accidentally comes loose, the bolt will not fall out.

 

[Darius Rudis]

...There are not enough threads showing on that nut. Two complete threads should show when the nut is fully torqued. 2. If this a-arm is right-side up, reverse the bolt. This way if the nut accidentally comes loose, the bolt will not fall out.

Thanks for the catch (pre-installed photo). Lots of extra threads when mounted correct side up orientation.

 

[JimmyMac]

It depends on your usage and what quality you want.
Here is a UK supplier which I have used and they always provide very good support and speedy delivery.

Bearings, Batteries, Lubricants & Application Tools | Autosport Bearings

Autosport Bearings supply bearings, fasteners, lubricants & more to the best motorsport teams. We have vast technical knowledge & provide the best service

www.autosport-bearings.co.uk

 

[Jay Gadsby]

Thanks very much for the pointers.

To get into this I went for some medium to lower cost carbon steel ends.
Avoiding anything that looked like it may be made fro Chinesium Steel.
To get started and will keep a close eye on the joints into the future.
Measuring carefully, and then measuring very carefully I was pleased with the fitting process which was much smoother than I thought possible (for me).

One of the lower wishbone rod ends had completely failed - the sphere having completely separated from the rod end body.

 

[Ian Clark]

Hi Jay,

It's a good idea to specify PTFE lined bearings for all applications (except throttle linkage). They require no lubrication however should not be left dirty or wet. Normally the premium paid for PTFE lined bearing also reduces the chance of buying a low grade part. Nylon lined bearings are cheaper but you really only want to do this job once.

You mentioned bearing failures, please make sure the rod ends do not go into "bind" through the total range of motion. Typically rod ends cannot tolerate motion deflection greater than 7-10 degrees from horizontal. The bearing supplier will have spec sheets indicating the allowable range of motion, hope this helps.

Cheers
Ian

 

[Jay Gadsby]

Hi Jay,

It's a good idea to specify PTFE lined bearings for all applications (except throttle linkage). They require no lubrication however should not be left dirty or wet. Normally the premium paid for PTFE lined bearing also reduces the chance of buying a low grade part. Nylon lined bearings are cheaper but you really only want to do this job once.

You mentioned bearing failures, please make sure the rod ends do not go into "bind" through the total range of motion. Typically rod ends cannot tolerate motion deflection greater than 7-10 degrees from horizontal. The bearing supplier will have spec sheets indicating the allowable range of motion, hope this helps.

Cheers
Ian

Thank you for adding this info Ian -

One thing that I don't think has been mentioned and continues to puzzle me is -

What an acceptable load rating should be for a rod end in a suspension set up, eg - lower rear wishbone to chassis.

This joint is the one under the most load - is this the case?

Am I overthinking this?

On balance I don't want to fit one for it to fail.

But then again I don't want to over spec and over pay for no good reason.

Thanks

 

[Neil]

Thank you for adding this info Ian -

One thing that I don't think has been mentioned and continues to puzzle me is -

What an acceptable load rating should be for a rod end in a suspension set up, eg - lower rear wishbone to chassis.

This joint is the one under the most load - is this the case?

Am I overthinking this?

On balance I don't want to fit one for it to fail.

But then again I don't want to over spec and over pay for no good reason.

Thanks

I just checked Rod End Supply and a 1/2" right- hand thread high strength alloy Teflon- lined rod end was $9.48. Your application is probably similar but check the bore, threads, and whether you might need a high-misalignment type.