Rod Ends & Spherical Bearings

[JHerscher]

Without starting a war of opinion data, does anyone have experience and comparison between the higher priced Aurora/NHBB/etc. and the much cheaper FK/QA1/etc. at usually half the price or less?

The specifications and construction are virtually identical and, let's face it, we all spend quite a bit on this sport and at around 30 or so rod ends or sphericals for your average formula car, it adds up quickly.

I'm aware of where they are made, and that personal opinions may vary, what I am looking for is first hand experience or empirical data to support the opinion.

Thanks

[Hawke]

I’ve been using the QA1 ends for about 20 years. I only replace one or two a race season. They seem OK for me.

[Phil Creighton]

As an ex NMB distributor this has been a question since I came over in the late 70's - anybody remember Rose Joints or Ampep. They were generally just fine in FF FC and similar uses - not fancy, Rose were machined and Ampep were cast. Both had teflon liners. Probably 1/2 the strength of NMB stainless but worked just fine. Same argument as grade 5 bolts vs AN hardware.
Generally the expensive ones last longer as they tend to be understressed so there are arguments about cost and life.

I would say that after reading some of the aluminum rod end specs I wouldnt use them in stressed areas even though they claim various loads. Not been my experience! Nose frame and shift linkage is the only place I have used them.

[Rick Kirchner]

when I first built my FC in '03 I replaced many of the critical rod ends and sphericals (on a '94, it seems to be the rear legs of the front arms, the front legs of the rear arms, and the shock eyes). I used FK and QA1s. Seems like they would last about two years.

A while back (and I mean a long while - like '07-ish) I wrote the Aurora guy asking some of these questions, and he sent me a complete assortment, of mixed Aurora types - to use in a test. They were scattered about the car - I have a map if anyone is interested, but it was an assortment of RXAB, PRXM, XAM, PWB, XAB, AU series parts.

But the bottom line is this - in my data [prior to '07, all the joints on the car that were worn out were either Rose or FK. Of the stuff I put on the car in 07 (and most of which is still on the car now) the only stuff that wore out were Rose and FK, replaced with more Aurora parts.

That stuff probably has 60 weekends on it by now, and I believe I will need to replace the joints on the lower rear legs of the front wishbones, the upper front legs of the rear wishbones, and the shock eyes again. Everything else is fine.

So I would say buy the cheaper series of auroras and call it good. They will last far longer than the cheaper stuff. I don't know if there's a quality difference in sphericals, but those shock eyes sure seem to take a beating. Maybe undersized a bit for the task.

[FVRacer21]

when I first built my FC in '03 I replaced many of the critical rod ends and sphericals (on a '94, it seems to be the rear legs of the front arms, the front legs of the rear arms, and the shock eyes). I used FK and QA1s. Seems like they would last about two years. A while back (and I mean a long while - like '07-ish) I wrote the Aurora guy asking some of these questions, and he sent me a complete assortment, of mixed Aurora types - to use in a test. They were scattered about the car - I have a map if anyone is interested, but it was an assortment of RXAB, PRXM, XAM, PWB, XAB, AU series parts.But the bottom line is this - in my data [prior to '07, all the joints on the car that were worn out were either Rose or FK. Of the stuff I put on the car in 07 (and most of which is still on the car now) the only stuff that wore out were Rose and FK, replaced with more Aurora parts.That stuff probably has 60 weekends on it by now, and I believe I will need to replace the joints on the lower rear legs of the front wishbones, the upper front legs of the rear wishbones, and the shock eyes again. Everything else is fine.So I would say buy the cheaper series of auroras and call it good. They will last far longer than the cheaper stuff. I don't know if there's a quality difference in spherical, but those shock eyes sure seem to take a beating. Maybe undersized a bit for the task.

I have worked with John from Aurora for a long time. His recent statement was even the MM rod ends can probably handle the loads, considering the cornering forces are distributed through multiple rod ends. Of course some handle more than others and add in heavier cars and ground effects and ymmv.

When we ran Crossle FFs in the Skip Barber School/Series, we found the AMPEP on the inner lower a-arm would develop play. We upgraded just that. Short of crashing a car - don't remember much problems. I think we calculated 10,000 miles in between rebuilds on the cars - of course - many did not get that far! Any bent part and the rod ends on it were tossed.

I do have a vague recollection of English and Irish FF's using some odd combinations of shank and bore size along with some high misalignment rod ends. Unless you can sleave the bore down, you might be stuck with a special end...

I just did a list/comparison of rod ends for my Citation FV and the price from Pegasus was less that than the comparable off brand rod ends from Summit. I will have to add QA1 to my chart and get back to you.

ChrisZ

[problemchild]

I realize that I tend to go against many of the long-lasting theories of the racing community, and that will continue. I have well-designed race cars in my fleet and I am confident in the integrity of the bearings used on them. So I am much more worried about "stiction." In most applications, regardless of cost. I would rather have a medium quality rod end that is 2 years old than a new top-of-the line rod end. On items such as sway bar links, I will take out the factory supplied rod ends out for use in more important items and replace with used "sloppy" rod ends. If I see people changing out the spherical bearings in shocks, I ask for the "take offs" and will use them. I will take a hammer to the spherical joints in modern A-arms to loosen them up. My cars tend to have very good mechanical grip and I don't think my focus on reducing "stiction" is a coincidence.

[halcyon]

I have been replacing mine with the most expensive high precision Aurora as they fail. None of these have failed even after 100s of hours of use in some cases. To me, an on track failure and loss of a qualifying or race session isn't worth cost savings for a cheaper option.

[billtebbutt]

I realize that I tend to go against many of the long-lasting theories of the racing community, and that will continue. I have well-designed race cars in my fleet and I am confident in the integrity of the bearings used on them. So I am much more worried about "stiction." In most applications, regardless of cost. I would rather have a medium quality rod end that is 2 years old than a new top-of-the line rod end. On items such as sway bar links, I will take out the factory supplied rod ends out for use in more important items and replace with used "sloppy" rod ends. If I see people changing out the spherical bearings in shocks, I ask for the "take offs" and will use them. I will take a hammer to the spherical joints in modern A-arms to loosen them up. My cars tend to have very good mechanical grip and I don't think my focus on reducing "stiction" is a coincidence.

Greg,

I recall one of the best fabricators I know fitting new a-arms with rod ends - he would put a bolt through the rod end and tighten a nut up against the other side. Then he'd chuck the bolt in a had drill, and spin the spherical "just" until the teflon heated up a bit and "gave" a titch. Best of both worlds - new unstressed rod end and minimal stiction as you call it

best,
bt

[Spengo]

How do you know when to replace rod ends? Is it a scheduled thing or more based on if it just feels too sloppy? What does too sloppy look like? Should you take apart the suspension and check them all regularly or just do it as the opportunity arises?

[Rick Kirchner]

in my case, I replace them when there is so little "stiction" that there's considerable "thunka thunka" when the joint is isolated and moved. The link lengths will exaggerate it, but I'm guessing that translates to about 1/32 to 1/16 of an inch.

I would also guess that too much "thunka thunka" translates into faster wear on the rest of the joints. I'm betting that the longevity in my parts is to some extent due to replacing nearly all of them in 07.

Of course I ran on some pretty smooth track from 07 to 14, then moved back east. After Saturday's events at a race at Charlotte one of the guys came up to me and said "we knew you weren't around here from looking at your ride height". Although I found Roebling to be pretty smooth.

On return to the west coast, everything had gone completely to hell. Our fire and safety guys carry cold patch to address the chuckholes at Willow Springs, the front straight at Buttonwillow would knock you fillings loose, and the infield at Cal speedway was as bad as Willow.

So, I'll be addressing a few loose parts this off-season, hoping the the new Buttonwillow track to finally be finished, the second half of the Willow re-pave to go off without huge seams, and RIP Cal Speedway...

[kea]

Unlike the cars of the 60's and 70's, starting in the 1980's the rod-ends and spherical bearings got smaller in size (fasteners too). For those I use ( if size is available ) the Aurora, Performance Racing Series bearings. Even though their description may look the same, we found them to outlast many others.
Once I find something that works for me, I'm not likely to change.

[problemchild]

Keep in mind, that my desired "free" bearings have probably less than 1/64th of freeness, typical of a joint that is several years old. If you need a lever more than 3" long to move the ball, then it is too tight. I am not suggesting 30 year old bearings with 1/8" of "slop". The concept of changing every piece of hardware when you buy a used race car is a bit over the top, and certainly not necessary. It is a "feel good" process that hopefully means that the whole car gets looked at in doing so. If after changing all that hardware, you don't have a long worklist, then your mechanic did not look very hard, or you bought a really good car (that did not need new hardware). New hardware is also a visual "receipt" for all the money paid to the shop for the "ground-up rebuild."

[tstrong]

Greg,

I recall one of the best fabricators I know fitting new a-arms with rod ends - he would put a bolt through the rod end and tighten a nut up against the other side. Then he'd chuck the bolt in a had drill, and spin the spherical "just" until the teflon heated up a bit and "gave" a titch. Best of both worlds - new unstressed rod end and minimal stiction as you call it

best,
bt

Have been using this drill method for years to “loosen” up new rod ends before installing. Takes a little practice/patience to get the right temp to get right looseness without overheating but works well. Have used everything from low end cheapies to NMB/NHBB cres and Fafnir very expensive ones. Have settled on medium priced Aurora AM series as a great compromise . Good strength, excellent wear/ life, and readily available. Todd

[FVRacer21]

Greg,

I recall one of the best fabricators I know fitting new a-arms with rod ends - he would put a bolt through the rod end and tighten a nut up against the other side. Then he'd chuck the bolt in a had drill, and spin the spherical "just" until the teflon heated up a bit and "gave" a titch. Best of both worlds - new unstressed rod end and minimal stiction as you call it

best,
bt

Here is some info about this:
https://flipbooksbyadventure.com/RodEndsCatalog/#22

ChrisZ

[problemchild]

To each his own, but if I am going to mutilate a rod end to get the desired "freeness" it will be a medium-priced part and not a top-end part. Why destroy a $48 part when a $22 part will be equally destroyed, probably for less effort?

Yes I know that if I have to ask, I won't understand the answer.

[S Lathrop]

I go for the lowest grade rod end I can get away with. For the out board rod ends, those at the uprights, in high shear loaded positions, I use top grades. But at the chassis end, I use the lowest grade I can. In the event of a crash, I want the rod ends to fail before any damage is done to the inboard pickup point.

Years ago, at the Atlanta run offs, a customer removed the left front corner and only the rod ends broke. We replaced the broken rod ends, aligned the car and were ready to go back on the track. All the control arms survived, undamaged.

[Hardingfv32]

Low rotational breakaway torque - Stiction

So assume you need to buy new rod ends. You want something with low rotational breakaway torque. Who has something like that? I noticed that the big manufactures have this as a option for the aircraft industry but I have have not seen much online.

Brand new formula cars should be using something that is appropriate, is that the case?

I was not impressed working over new rod ends in a lathe.

Brian

[R. Pare]

We used to free up the rod ends on some of the cars we built or serviced. Install the bolt and nut, stick in a drill press, and spin at 900 rpm until you could feel just a bit more drag, then stop and quench with water to cool down.

What you are doing is heating the teflon so that it expands, but the only place it can expand to is lengthwise. The quenching then quickly cools the exposed ends, while the rest of the assembly takes slightly longer. The teflon sheet cools to slightly thinner than it was originally, creating less clamping load on the ball ( it also helps transfer some of the teflon onto the ball), with both changes giving less stiction.

Never had a lifing issue with this. Always with Aurora bearings, except for the first time we tried FK on Lou Coopers car, when they were first coming onto the market - even without loosening them, they hammered out in just one weekend.

[TimH]

But at the chassis end, I use the lowest grade I can. In the event of a crash, I want the rod ends to fail before any damage is done to the inboard pickup point.

Lowest grade bolt as well. Lesson painfully learned on my Caldwell.

[DaveW]

Low rotational breakaway torque - Stiction

So assume you need to buy new rod ends. You want something with low rotational breakaway torque. Who has something like that? I noticed that the big manufactures have this as a option for the aircraft industry but I have have not seen much online.

Brand new formula cars should be using something that is appropriate, is that the case?

I was not impressed working over new rod ends in a lathe.

Brian

I've found (maybe coincidentally) that rodends purchased from Pegasus have seemed to need less massaging to get to the proper tightness than those purchased directly from rodend manufacturers. Seems like they may spec them to some smaller than usual degree of tightness.

[Westroc]

I'm older mow and my crew guys were counting how many cars we had done on our jorney. I think we arrived at 26 that we can remember. Almost always I bought rod ends from Averill. Sharing what I have learned is 2 big things. First it's always Aurora except for :no load: stuff. The problem seems to be that just about nobody uses any antiseize on the reduces that you insert.. Almost every car I bought. You race in the rain?? Ever?? Try and get them out especially if you want to reuse them. You say I;ll knock them out. Then redrill them round? Not good X20 ends. Plus now you are shipping half a pound of reducer for 20-30 bucks. What did you save?
The second is keeping them absolutely clean. If you don;t cut the life in half.. Jim.

[DaveW]

I'm older mow and my crew guys were counting how many cars we had done on our jorney. I think we arrived at 26 that we can remember. Almost always I bought rod ends from Averill. Sharing what I have learned is 2 big things. First it's always Aurora except for :no load: stuff. The problem seems to be that just about nobody uses any antiseize on the reduces that you insert.. Almost every car I bought. You race in the rain?? Ever?? Try and get them out especially if you want to reuse them. You say I;ll knock them out. Then redrill them round? Not good X20 ends. Plus now you are shipping half a pound of reducer for 20-30 bucks. What did you save?
The second is keeping them absolutely clean. If you don;t cut the life in half.. Jim.

Interesting - in my 50+ years of racing I've never been unable to get the spacers out. And we've had all types - Aluminum, mild steel, hardened steel, SS. Wonder what I'm doing that's unusual.

[SteveG]

Interesting - in my 50+ years of racing I've never been unable to get the spacers out. And we've had all types - Aluminum, mild steel, hardened steel, SS. Wonder what I'm doing that's unusual.

You regularly maintain your racecars by taking them apart and putting them back together, that could be considered unusual.

The Swift DB2 that I recently rebuilt had nearly all of the spacers either frozen in place or worn out to the point of being unusable. More than half of the rod ends and 90% of the nuts and bolts where original Swift factory pieces. The car was obviously lightly maintained.

Steve