Bushings - science experiment

[toolman.dustin]

A topic that never fails to generate strong differences of opinions.
Bushings: bronze, nylon or the ever elusive "NeverFail".

In April 2023, I replaced my, once again, failed bronze bushings with new bronze bushings. Put the trailer in storage and brought it home to prep for an upcoming trip. Total distance on these new bushings is less than 60 miles!
I decided to replace the front axle leaf springs after close inspection and they appeared flatter than they should appear.

Anyway, after removing the old springs I inspected the brand new bushings. All 4 (from both springs) were already damaged. (attached photo). I decided to order the "NeverFail RV Suspension Lubrication Bushings" bushings from Camping World and installed them on the front pair of springs. I'm leaving the bronze on the rear axle springs. I'll inspect them all in about a year and see how they compare.

The real problem seems to be the "eye hole" in the springs is not really round, since it's forged, so the bronze bushings just get deformed trying to fit in an "un-round" hole. I suspect the NeverFail have a better chance since they are flexible. I've read a couple of posts suggesting that if you ream the eye hole and make it round the bronze bushings will last a long time. I purchased an 11/16" drill bit last spring and tried to drill the holes round, but some of the holes were larger than 11/16" and the bit just dropped through hole without making contact.

I'll update you after a couple thousand miles have been added. I've attached a couple of videos that demonstrate how leaf spring eye holes are manufactured.

Dustin


"https://www.youtube.com/watch?v=9Aap1QosGF8"

"https://www.youtube.com/watch?v=-3e5GZx_8jg"

 

[Hoopy Frood]

FWIW, if the spring eyehole isn't round, which is likely, then the pressed in bushing isn't going to be round either. That's why the bushings should be reamed after they are installed. I found that all the bushings I installed needed to be reamed after installation. I haven't checked my bushings so I have no idea how they look, but any bushing should be reamed after it's installed. Not with a drill though, but with an actual on-size reamer.

And drilling/reaming a spring eye can be a daunting task since the spring steel is extremely hard. It can be done, but not easily, and not without an element of risk.

 

[traveldawg]

FWIW, if the spring eyehole isn't round, which is likely, then the pressed in bushing isn't going to be round either. That's why the bushings should be reamed after they are installed. I found that all the bushings I installed needed to be reamed after installation. I haven't checked my bushings so I have no idea how they look, but any bushing should be reamed after it's installed. Not with a drill though, but with an actual on-size reamer.

And drilling/reaming a spring eye can be a daunting task since the spring steel is extremely hard. It can be done, but not easily, and not without an element of risk.

A couple of questions... probably mostly for my edification but it might help the group...

It sounds like you haven't changed your bushings ("...haven't checked my bushings so I have no idea..."). Is that correct? Or have you replaced them? If you replaced them did you ream them?

Are you suggesting to ream the new business once they are installed? Or are you suggesting to ream the eye of the spring?

If you ream a new busing after it is installed, isn't it: 1) going to be larger than it should be for the bolt? 2) just going to deform again because the spring eye still isn't round?

No doubt that business are a real failure point in these kinds of suspension systems. I found that when I installed a MorRyde SRE4000 system even the (supposedly) round hole in the equalizer itself wore the bushing and even deformed the 'round' hole after many miles (lets say around 15,000).

Not trying to imply or say that reaming is bad. Just hoping to get some clarification on the idea. Thanks.

 

[Hoopy Frood]

FWIW, I worked in the can manufacturing industry for 40 years, most as a mechanic. We never installed any bushings without reaming them afterward. It ensures that the hole you want is to size and perfectly round. Running an 5/16" reamer though a bushing that is smaller than 5/16" will result in a bushing that is exactly on size, and round, not egg-shaped. You won't remove more than 5/16" and thus won't end up with a bushing that is too large in diameter.

I changed out my bushings when I installed the 4,000 lb. rated springs in place of the OEM 3,500 lb. rated springs that had flattened. Yes, I reamed all the bushings because all had deformed to a certain degree when pressed into the spring eyes, which as you know are not as true as they could be. All the reaming does is make sure the bushings are actually on size. I did it mainly because I've always done it. As to whether it will deform again due to the spring eye not being perfectly round, that could certainly happen, but I can't say positively. But IMO, starting out with round bushings is better than starting out with egg-shaped bushings.

As to reaming out the spring eye. It's doubtful you could ream it due to the hardness of the spring. And the fact that the spring is not a complete loop, but a rolled over end. You could set it up in a machine and have the hole cut completely round, but that's pretty impractical, since it would have to be set up in a milling machine. And the bushings would have to be custom sized when finished.

Actually, IMO, it's not too surprising that the bushings fail in these springs due to the fact that a brass bushing isn't really designed to withstand the forces in play on a loaded suspension. Bushings are mainly designed to allow a part to spin within the bushing, not absorb the pounding these spring eyes receive. Probably hardened steel would be a better choice than brass, maybe heavy duty roller bearings. IMO brass is a poor choice for this application.

 

[Tony_in_AZ]

I wonder if a small drum sander or a flex type dingle ball hone would smooth out the inner surface? Not a precision round hole attempt, just smooth the bore a bit ?

 

[Hoopy Frood]

It would likely work, but how would you know where you need to sand? You could end up with an overly large, out-of-round bore.

 

[traveldawg]

I guess the bushings are the designed in "wear point". It's just too bad that they wear out so fast.

Automobile (car and truck) springs never had/have this issue. Someone needs to come up with some sort of neoprene-type bushing like on cars and trucks (and on shocks).

 

[Second Chance]

Thread moved to Axles, Brakes, and Suspension.

Rob

 

[toolman.dustin]

Actually, IMO, it's not too surprising that the bushings fail in these springs due to the fact that a brass bushing isn't really designed to withstand the forces in play on a loaded suspension. Bushings are mainly designed to allow a part to spin within the bushing, not absorb the pounding these spring eyes receive. Probably hardened steel would be a better choice than brass, maybe heavy duty roller bearings. IMO brass is a poor choice for this application.

I agree. The eye hole is supposed to be 11/16" and the bolt hole 9/16". If the eye hole is egg shaped and 11/16 at the narrowest part and say 12/16" at the wide part then the bushing will fit in the hole. But then, turning the trailer causes the bolt to exert stress on the bushing and the bushing will be expanded into the 12/16" space. Since bronze doesn't stretch very well, it's certain to crack.

I found this article that discusses the advantages and disadvantages of brass vs bronze bushings. Thought it was interesting. My original OEM nylon bushings were toast after the 2,000 miles. So, I switched to bronze before I realized the hole isn't round.

The most effective solution would be to make the eye hole undersize, say 10/16, and then drill it to a perfect 11/16. Then the hole would be round and fit the bushing properly. But, you are correct, these bushing take a horrible beating diving down the road but they really get twisted and tortured when we back into parking places.

"https://bushingmfg.com/brass-bushings-vs-bronze-bushings-how-to-choose/"

Dustin

 

[2psnapod2]

I keep an eye out on these kind of posts and wanted to chime in here. Performance Trailer Braking has the Never Fail bushings also.

I mainly wanted to say that if someone milled a piece of round stock the size of the inside of the bushing that had a lip on it, it would ensure the bushing remained round when installed.

 

[Hoopy Frood]

Well, it might remain round as long as the stock was in place, but it would try to deform, and once you removed the stock, it would deform. And it's possible the round stock would have to be driven out if the bushing distorted enough, and then you've got a tight bushing. Only way to absolutely insure the hole is round and on-size, is to ream the bushing after installation. The main issue with these spring eyes is they are not round, and the bushing isn't completely supported.

 

[ajg617]

Interesting that this subject (more like broken wet bolts but clearly bushing failure included) came up on the other forum. It's not just a GD issue if you search "wet bolt failure in rv's" in google.

I was kind of stunned when the GD mobile tech pulled the front wet bolts out with gouges in them at the bushing ends at the bolt head. The bushings (and spring eyes) were oval but which came first? I can say that Dexter/LCI's response to Don Clark's crew was 'not covered' due to terrible roads. IMHO, there's a flaw in that argument.