NDR, vehicle suspension question... camper leaf springs...

[tod osier]

Having a problem with my camper suspension, specifically the spring bushings. I keep wearing out the leaf spring bushings in my camper suspension after a relatively short time. I have what people consider the best of the best suspension upgrade within the RV industry for a camper of my size and it isn't holding up (Dexter heavy duty suspension kit, which includes wet bolts, heavy duty shackles and bronze bushings). I'm on my second set. The first completely self destructed after 35K miles (most bronze bushings worn through and springs riding on the bare bolts) and the second after a full rebuild including springs is three months old with 12K miles and is failing (bushings heavily worn and noticeable wear on the bolts). I know trailers and trailer parts are half-assed, so I'm wondering about how it is done other industries.

Question... what are the spring bushings of typical vehicles (not trailers) that use leaf springs made of? They look like some of them are steel inside of rubber in the photos I've seen, so the steel inner of the bushing is riding on a steel bolt. Steel on steel in some and it works. I've never messed around with anything other than trailers, so I just don't know.

Where I'm going with this is that I thought the bronze bushings were used in the premium trailer suspension kits because the bronze on steel wears well. What I'm finding is that the spring eyes are not round and don't support the bushing and the bushing deforms from the pounding on the road and cracks and wears the bolt unevenly. The bushing are only 1/16" thick - this is a clearance issue with the size of the standard spring eye and the size of the bolt that is a design constraint (standard bushings are plastic and fail very fast too). I'm now thinking they use bronze because a steel bushing could not be press fit into an out of round spring eye and there isn't room for steel and rubber. I'm wondering about going with a steel bushing on a wet bolt, maybe even trying to ream the spring eye slightly to get a uniform shape so I can get a properly sized bushing in there. I can also just change all the parts out every 15K miles, but that is kind of a pain in the ass and the price adds up.

Thoughts????

 

[Carl]

Yikes, scary that they are wearing out that fast.
I dont know squat about bushings but:
Our camper has a torsion spring axle, it's a 1973 model and still going strong.
I know that a replacement axle for ours is relatively inexpensive, is a retro-fit an option on yours?
Given how far you trailer, you might want to consider it????

https://www.trailerpart.com/c-26-torsion-axles.aspx

 

[tod osier]

Thanks Carl, but I rebuilt the suspension from the ground up this year, including axles, brakes, drums and springs... I was going to just do axles (had drop axles and wanted straight, had a slightly bent spindle, etc...) and brakes (wanted self adjusting, needed new brakes). I peeked at the springs and bushings when I had it apart to make sure they were okay and I found they weren't, so I replaced everything in May before Alaska.

 

[Capt Rich Geminski]

Tod, had a p/u camper and had to add springs. The helper springs were only in use when the camper was on, regular springs were good for normal use.
Did you check tongue weight? There is a formula, but can't remember it at my age/

 

[Eric Patterson]

Tod

I just replaced the suspension on my Toyota Pickup project. I bought springs, bushings, etc. from Old Man Emu (Aussie company) which is a respected name in the off-road community. Their design uses greasable polyurethane bushings that have a hollow bolt with grease ports that passes through them. I haven't had my set on long enough to know how much of an improvement it is over standard rubber bushing set-up but it sure seems like a good design. The link below will take you to a good picture where you can see the parts.

https://www.quadratec.com/products/16090_900.htm

Edit: The leaf spring bolts on my pickup pass through the poly bushings with no sleeve. The bolt rests on the bushing with grease on all the surfaces. I'm surprised your bronze bushings fail so soon. Makes me think they are undersized for the load.

 

[tod osier]

Tod

I just replaced the suspension on my Toyota Pickup project. I bought springs, bushings, etc. from Old Man Emu (Aussie company) which is a respected name in the off-road community. Their design uses greasable polyurethane bushings that have a hollow bolt with grease ports that passes through them. I haven't had my set on long enough to know how much of an improvement it is over standard rubber bushing set-up but it sure seems like a good design. The link below will take you to a good picture where you can see the parts.

https://www.quadratec.com/products/16090_900.htm

It looks like the inner (part that rides on the bolt) of the poly bushing are steel from the photo, not bronze. Is that right?

My suspension upgrade is greaseable in the same way.

 

[Eric Patterson]

It looks like the inner (part that rides on the bolt) of the poly bushing are steel from the photo, not bronze. Is that right?

My suspension upgrade is greaseable in the same way.

See my edit. We were typing at the same time.

 

[tod osier]

Edit: The leaf spring bolts on my pickup pass through the poly bushings with no sleeve. The bolt rests on the bushing with grease on all the surfaces. I'm surprised your bronze bushings fail so soon. Makes me think they are undersized for the load.

Really surprised at poly on steel, interesting.

I don't know what to think on the whole thing. As far as being undersized for the load, the kit is sized for up to 6K axles and my axles are oversized for my trailer at 3.5K and I probably don't run with more than 2K on them, so I'm way under. I'm pretty good at researching stuff and I can't really find where people are having failures like I have. The manufacturer is sending me new parts and they will look at the old stuff for me when I replace it.

Just some pics...

Spring dropped after 12K miles...

Bushing. It looks ate up from driving it out, but the shape is as it conformed to the spring eye.

Wear on the bolt matching the bushing.

 

[Eric Patterson]

Looking at your pictures makes me think part of the problem is dust getting in there and acting like an abrasive. I agree, the wear looks excessive for the mileage. I hope you can come up with a solution.

 

[Phil Nowack]

Could the ALCAN Hwy be a primary contributing factor?

 

[tod osier]

Looking at your pictures makes me think part of the problem is dust getting in there and acting like an abrasive. I agree, the wear looks excessive for the mileage. I hope you can come up with a solution.

Got dust for sure. The greasing interval is 3000 miles, which is a total pita on a trip (but also has to move some grit out).

 

[tod osier]

Could the ALCAN Hwy be a primary contributing factor?

Good problem to have, I guess. The Alcan is just long and not great road, the roads in ak were pretty bad this time with endless frost heaves.

 

[Sandy Allen]

I've also heard there is a lot of wear and tear on the Alcan. Some one told me about towing an aluminum boat with a cooler containing soda cans. By the time he got to his destination the cooler had worn a hole in the boat and the cans had worn a hole in the cooler! I really enjoyed your previous post and the pictures.

 

[kladd1]

I have worked in the suspension industry for over 30 years, your problem is not uncommon. First it is difficult to roll a perfectly round eye for the smaller diameter spring bushing. It appears you are keeping them greased but the thin wall on the bushing will only last so long especially under a heavier load and or rough roads. One option would be to have springs made with a bigger diameter eye that would take a thicker walled bushing, that is if there is enough room in the frame hanger to accept the larger eye. Also be sure not to over tighten the rear shackle bolts, the spring needs to move freely when reacting to bumps in the road.

 

[tod osier]

I have worked in the suspension industry for over 30 years, your problem is not uncommon. First it is difficult to roll a perfectly round eye for the smaller diameter spring bushing. It appears you are keeping them greased but the thin wall on the bushing will only last so long especially under a heavier load and or rough roads. One option would be to have springs made with a bigger diameter eye that would take a thicker walled bushing, that is if there is enough room in the frame hanger to accept the larger eye. Also be sure not to over tighten the rear shackle bolts, the spring needs to move freely when reacting to bumps in the road.

Thanks Kevin, I appreciate you sharing your experience. Just the sort of person I was looking for. I'm greasing them like crazy, the spec is every 3K, which is a lot. Another member of the brain trust here suggested just the same thing in a PM (thanks Dave) . I put new springs in just in May, so that is a downer, but it seems like a long-term solution. There is plenty of room there for some larger eyes in the hangers and the other components. Would you say to use a bronze or poly bushing with a new spring with larger eyes or try to find an commercial rubber and steel bushing? It seems like most springs are wider than the 1.75" of camper springs. Do you have a suggestion for a custom spring maker if I needed to go that route?

All the bolts are step bolts, so no over tightening.

 

[tod osier]

I've also heard there is a lot of wear and tear on the Alcan. Some one told me about towing an aluminum boat with a cooler containing soda cans. By the time he got to his destination the cooler had worn a hole in the boat and the cans had worn a hole in the cooler! I really enjoyed your previous post and the pictures.

Thanks Sandy, I missed responding when you put it up - sorry. I believe that road chews stuff up, but it isn't that bad, just long and roughish. I know it chews tires up, the tread just disappears. I did this trip on older tires because I'm too cheap to destroy a new set on the first trip out. I think that is poor logic, but I did get home on those tires (2 were not street legal by the time I rolled in).

 

[Huntindave McCann]

,,,,,,,,,,,,,,,,,,,,,,, but I did get home on those tires (2 were not street legal by the time I rolled in).

You rebel, you.

I too can confirm the visible tread wear that occurs on an extended trip.

 

[tod osier]

Not a rebel so much as cheap, but I will not also pretend that it didn?t cause me some stress (which was dumb since I now have new tires and the truck will be for sale within the year). Cheap and dumb, right there.

 

[Brad Taylor]

The problem is the brass bushing. It's too soft and can't take the pounding (but you already know this) You will either keep replacing them or change to a polyurethane insert.

I have built and designed many suspension systems on both trailers and BIG 4x4 trucks and have never seen that kind of failure on so few miles. But I have also never seen a brass bushing used in that capacity. I have only ever seen brass used in a rotational configuration ie instead of a roller bearing

Width of the spring won't be an issue as you can cut down any poly bushing to size. The spring eye and bolt size is an issue. If you get custom made ask them to fit a standard poly bushing that they stock.

We've been to Alaska twice and to the NWT and the yukon in our truck. It's not the roads, it's the design of your suspension

Our 11000lbs land cruiser suspension with Old Man Emu (as posted above) shackles and poly bushings. The bushings last about 50000miles

A poly bushing on a trailing arm. Notice it has a metal insert for the pin to ride on AND a grease nipple. Rougher ride then above, I haven't worn a set out yet.

And a hiem joint for a trailing arm. It's metal on metal (no bushings) rough but tough. Haven't worn these out either.