Bronze Spring Eye Bushing Life

[Flyinfish]

After breaking another spring on our GD 297RSDS on our last trip and getting it fixed in Gallup, NM, I was afforded the opportunity to inspect what was left of the bronze spring eye bushings in them. I replaced the hanger components, including bushings, in June '24 with the recommended wet kit. Bushings in both ends of both springs were worn through on the weight bearing upper side. I installed all this to get some extended life out of them. 5600 miles doesn't seem like very extended life and I grease them regularly. Why spend the money on this kit when I can get the same life out of the much cheaper plastic bushings and non-greasable bolts? Anyone have any solutions?

 

[Chaps2018]

What was the mileage interval that you greased them?

 

[Flyinfish]

Every other trip or so. It's easy to do so it gets done. I took the non-broken spring one to my local trailer supply shop to ask them. One looked at it and said "well they're greased". They only have 7 trips on them...364, 260, 500, 630, 340, 340, and 3400 miles. Am I supposed to stop every 500 miles and grease them? After every trip? I put these things on so I wouldn't have to change them out every 5,000 miles. Well that's out the window...I'm better off with the plastic ones and regular bolts. It'll be a lot cheaper.

 

[Chaps2018]

Just curious since the grease interval from Dexter is every 3k miles--sounds like you are satisfying that interval. The way tandem axle trailer suspension work, it's hard to see how any bushing solution could work. I recognize you mentioned ONLY spring hanger bushings but I think about them similarly across the entire suspension line since if one needs greasing might as well be all of them. Perhaps this is an oversimplified approach tho.

You have three choices when it comes to the bushings/shackle straps.
-Wet bolts w/bronze bushings (advantage is thicker shackles that come with the Dexter Ez Flex kit)
-Never fail bushings from Lippert (now very hard to find, if not discontinued all together)
-OEM grade nylon

Our SOB rig came with standard Dexter equalizers/nylon bushings. I started to look into the bushings after the suspension kept making noise. There is a short primer that I put together showing my findings down below. Two things that really opened my eyes.

1-OEM nylon bushings are not suitable as you have found. here is a pic of mine after 20k miles. I went to Never-fail bushings next...you can see they lasted much longer but still started to wear through at 20k mi. See this snippet from the doc below:

2-Shackle thickness can really affects mounting hole wear. The thicker shackles come with wet bolts. See this snippet from my doc below:

So, my conclusion was to stick with bronze bushings in order to get the thicker shackle straps. I changed the bronze bushings and they were worn somewhat at 30k miles so I just keep on greasing them.

Keep us updated on your conclusions.

 

[Scott'n'Wendy]

Spring eye bushing will not make it more than one year. The others will last quite a while. Spring eyes are out of round and kill the bushing very quickly

 

[Flyinfish]

Chaps2018...I agree with everything you say above. When I replaced the spring eye bushings I replaced everything to hold the axles in place...shackle straps, equalizers, and bolts. I have been a weldor/welding instructor for over 40 years with lots of trailers built and I always recommended the wet kit. But to get less than 6000 miles on a set of so called "high end" spring bushings is frustrating. I haven't checked the equalizer bushings...YET! I'd like to find some polyurethane bushings similar to what's used on off-road 4x4 rigs. They seem to last forever.

Scott'n'Wendy...absolutely agree and never gave it much thought. Any bushing replaced on equipment is precision machined. The spring eyes are the opposite of that regardless of where they're made. The equalizer has machined holes...I'll check them as well to see where we are. That being said, the load is still only on one side of the bushing wearing on a very small area. There should be no wear on the opposite side of the bushing.

,My supplier just kind of shrugged their shoulders when I showed them. And neither one is in agreement on mileage life of nylon bushings or bronze bushings. These things are not like a machine bushing that is rotating in a perfect arc. All the weight of the trailer is in one spot and never changing. I guess I need to quit my griping and just face up that I need to go through and change things out once a year. I have the tools/equipment and place to do it...the wet kit took me about 2 hours to change out. It'll be faster now that I have the tools built to make it easier. I think changing out the bolts might be a good idea as well due to the hardness of the spring material wearing on them as well.

I appreciate all the input. If it weren't for that broken spring, we would never have had this conversation. But that's a topic for another day.

 

[Scott'n'Wendy]

I guess I need to quit my griping and just face up that I need to go through and change things out once a year.

Dexter, GD etc say bushings should be inspected regularly. I haven't seen a published mileage or time for the term 'regularly'. Sooooo up to the individual I guess?
I find the bushings on the equalizer are always good due to the nice round holes and close fit.
It's your rearmost spring eye bushings that take the most abuse from suspension forces while stopping. So they always wear out first.

 

[TimtheToolMan]

What lubricant have you used with bronze bushings? About 5% moly content will help some (greater than 5% is a bit abrasive but may help with these extreme conditions) but clearly is not a fix. It is really messy stuff so that is a downside. Unloading wheels when lubricating may help some. A radically different design is needed.

 

[Conner58]

Well pickup trucks been using this for a long time and go hundreds of thousands of miles .
So it can be done .

 

[Scott'n'Wendy]

Well pickup trucks been using this for a long time and go hundreds of thousands of miles .
So it can be done .

Using what?

 

[Conner58]

Using what?

Leaf springs . Sorry i thought the topic was leaf spring and I bolt bushings .

 

[Steven@147]

if I had a lot of time, money and we were not fulltime, and I had my old shop back I would look into redesigning the bushing suspension. I would use a metal encapsulated rubber bushing something like the attached. I would look into having custom springs made with larger diameter spring eyes to accept the rubber bushing, but with the same overall spring pack length.

These rubberized bushings were made back in the day with various diameters and lengths to fit the older cars and trucks. Many of the rear leaf spring bushings were anywhere from 1.5 to 2 inch in outside diameter and used metal shackle straps to attach to the frame much like our RVs. The front leaf spring bushings were usually twice or three times the diameter of the rear owning to axle windup when we stuck our foot through the floorboard..

I've replaced these types of bushings on various Ford, Mopar and GM cars and trucks from back in the 60s, 70s and 80s. The performance bushings were made with polyurethane or IIRC a polygraphite rubber.

I think I would browse through Rock Auto on various old cars and trucks looking for a rubberized rear leaf spring bushing in the diameter I thought I could use then get custom made leaf springs with larger diameter eyes. The bushing length wouldn't be much of a problem cutting down the bushing to fit our 3/4 inch wide leaf springs, a simple hack saw / sawzall would work.

I would leave the equalizer alone with its bronze bushings. The frame hanger ends of the leaf springs are the ones that wear out the RV OEM bronze or plastic bushings. From what I've seen at least on our rig the frame hangers are already long enough to accept a larger diameter spring eye. But I have noticed that the newer Solitudes and Influence RVs I looked at, they have much shorter frame hangers so the frame hangers might need to be changed and lengthened.

I don't think it would really matter if the new larger diameter leaf spring eyes were not completely round. The metal outer sleeve of the rubberized bushing would compensate. Not like a soft bronze bushing getting deformed by an out of round spring eye. The rubber insert between the metal sleeves would act like an additional cushion for the suspension. Add some shocks and you get some of what the old cars and trucks had for suspension back in the day, of course minus the equalizer.

These rubberized bushings are what cars and trucks were using on their leaf springs for decades before they went to independent suspensions. They did wear out but after many, many years of use and they are still made today aftermarket.

 

[traveldawg]

if I had a lot of time, money and we were not fulltime, and I had my old shop back I would look into redesigning the bushing suspension. I would use a metal encapsulated rubber bushing something like the attached. I would look into having custom springs made with larger diameter spring eyes to accept the rubber bushing, but with the same overall spring pack length.

I'm kind of thinking like Steven@147. It seems like it would be better if there was a way to insert a rubber busing type arrangement into the spring eyes; then maybe the wet bolt to keep them lubed. Automobile springs and shackles don't have this problem and they use rubber bushings.

I think it is the basic out of round spring eye that causes the wear. If there were some more rounded surface for the bushing then I'm guessing it wouldn't wear as fast.

I suppose boring out the eye might work, but that might weaken the spring eye.

 

[Scott'n'Wendy]

I suppose boring out the eye might work, but that might weaken the spring eye.

I think a steel shell rubber bushing would be too large a diameter to do that?

 

[Scott'n'Wendy]

You would think it wouldn't be too big an ask of RV manufacturers to ask for bigger spring eyes from dexter etc?

 

[ajg617]

24K trailer miles. First set of bushings failed (disappeared) at 15K miles. Second set disintegrated at 5K (pic below is all that was left of 14 - including the equalizer bushings - greased by dealer, greased by me twice, greased by factory). Fourth set now and only a trip from Elkhart to NH. Guess we'll see on this set since everything below the frame was replaced. This whole business of checking the bushings by seeing if they take grease is so bogus - and that's what dealer and factory did. This pic was less than 1K after factory 'inspected' bushings last April.

 

[Scott'n'Wendy]

Hi John, they are probably going to blame it on the poor roads.....not their product.

 

[ajg617]

Hi John, they are probably going to blame it on the poor roads.....not their product.

Hi Scott,
Yes LCI said roads. GD at least replaced everything.

 

[Scott'n'Wendy]

Hi Scott,
Yes LCI said roads. GD at least replaced everything.

I wonder where the road is that is perfect enough for a trailer to not have suspension issues? Between our two countries and 1000's of miles, I've yet to find it.
Bridge transitions in Iowa on I35 are definitely not in the running.

 

[huntindog]

Just curious since the grease interval from Dexter is every 3k miles--sounds like you are satisfying that interval. The way tandem axle trailer suspension work, it's hard to see how any bushing solution could work. I recognize you mentioned ONLY spring hanger bushings but I think about them similarly across the entire suspension line since if one needs greasing might as well be all of them. Perhaps this is an oversimplified approach tho.

You have three choices when it comes to the bushings/shackle straps.
-Wet bolts w/bronze bushings (advantage is thicker shackles that come with the Dexter Ez Flex kit)
-Never fail bushings from Lippert (now very hard to find, if not discontinued all together)
-OEM grade nylon

Our SOB rig came with standard Dexter equalizers/nylon bushings. I started to look into the bushings after the suspension kept making noise. There is a short primer that I put together showing my findings down below. Two things that really opened my eyes.

1-OEM nylon bushings are not suitable as you have found. here is a pic of mine after 20k miles. I went to Never-fail bushings next...you can see they lasted much longer but still started to wear through at 20k mi. See this snippet from the doc below:
View attachment 1109078

2-Shackle thickness can really affects mounting hole wear. The thicker shackles come with wet bolts. See this snippet from my doc below:View attachment 1109079

So, my conclusion was to stick with bronze bushings in order to get the thicker shackle straps. I changed the bronze bushings and they were worn somewhat at 30k miles so I just keep on greasing them.

Keep us updated on your conclusions.

I installed my Never Fails and was able to keep the thicker straps....Just installed a small screw in the zerk hole of the new greasable bolts.