Trailer Spring Leaf Question

[C. Amick]

I have a 2-axle trailer that I am working on restoring. It has single leaf springs on it. Each leaf is around 3/4 inch thick at the axle and tapers down to around 1/4 inch thick at the spring bracket. I probably won't ever haul more than 2 tons on this trailer. I was wondering if these springs are adequate? Is there a source of information to figure out what their capacity is based on thickness? I have access to some multi-leaf (5 leaf) spring sets. I just didn't to do all the work to change them out if it wasn't necessary.

 

[Lazy WP]

I had those on my Donahue trailer. Mine was rated at 7000 pound axles.

 

[GlenIdaho]

Check out etrailer. I'm sure they would be able to help you. See the link below for a video on single leaf sprint.
spring

 

[GlenIdaho]

Should have added you might check out their FAQ's great info there. To help determine the rating of the spring you could gauge by the size of the axle diameter. Here's a list from etrailer.

Typical Axle Diameters Based on Axle Capacity
- 1,000-lb - 2,000-lb Axles: 1-1/2 inch - 1-3/4 inch diameter
- 3,500-lb Axles: 2-3/8 inch diameter
- 6,000-lb - 7,200-lb Axles: 3 inch diameter
- 8,000-lb Axles: 3-1/2 inch diameter
- 9,000-lb Axles: 4 inch diameter
- 10,000-lb Or more axles: 5 inch diameter

Example, if it is a 6000 lb axle then each spring would be rated at 3000 lbs.

Hope this helps.

 

[jon f mn]

Redneck shows those at 3,000 lbs each for 6,000 lbs/axle. Going to ride very rough with those springs.

 

[kcm.MN]

I had bought a new 16' tandem axle enclosed trailer a couple years back but, after using the trailer for the first time, found out that the springs weren't strong enough and the axles were bottoming out into the trailer. So I loaded up a 600-gallon steel water tank and figured out how many gallons I'd need to reach maximum capacity, including weight of trailer and tank. Had a dashcam mounted underneath the trailer. I filled with water about 300 lbs. shy of maximum load and even going up and down my driveway, the trailer bottomed out. Ended up buying springs for 5,200 lb. axles (originals were for 3,500 lb. axles) and haven't had a problem since! Sent the video in to the trailer manufacturer and they ended up reimbursing the cost of the new springs.

Still have the damage to trailer frame, but damage is minimal and "shouldn't" cause any problems.

I agree that eTrailer.com is a fantastic info resource!!

Also keep in mind that trailer tires are meant ONLY for trailers! Paying extra for comparable auto tires is, in my opinion, well worth the money if you plan on using your trailer a lot. I don't, so I stuck with radial trailer tires.

Lastly, newer trailers may have lights that are not set up for best to-ground contact. On this enclosed trailer, the fender lights grounded into the fender, but only using sheet metal screws. The lights spent more time off then on! So I replaced the sheet metal screws with machine screws with flat and lock washers and a nut. Haven't had so much as a flicker since.

 

[Geo-TH,In]

I used to have a 16 ft landscaping trailer, 7k, two 3.5k axles. I would bend the axles.

My 7k trailer had 5 lug wheels two 3.5k axles. My 10k dump has two 5k axles, 6 lug wheels. My 14k implement trailer has 8 lug wheels, two 7k axles.

I think it may be safe to say, the axle size may easily be determined by the wheels size. So why add heavier springs than your axle can support? If you put heavier springs on trailer, you may end up bending the axles and the trailer will bounce like a basket ball when it empty.

Count you lug nuts and don't over load axle.

 

[BarnyardEngineering]

(quoted from post at 22:55:22 02/27/17) I had bought a new 16' tandem axle enclosed trailer a couple years back but, after using the trailer for the first time, found out that the springs weren't strong enough and the axles were bottoming out into the trailer.

What was the trailer rated for? How many lugs on each wheel?

If they put 3500lb springs on a 5200lb axle, I'm with ya. But, if you put 5200lb springs on a 3500lb axle, you're destined for more damage somewhere down the road.

 

[marloweg]

they used them on mobile homes years ago your trail might have been home made using mobile home axles.

 

[kcm.MN]

(quoted from post at 05:44:11 02/28/17)

(quoted from post at 22:55:22 02/27/17) I had bought a new 16' tandem axle enclosed trailer a couple years back but, after using the trailer for the first time, found out that the springs weren't strong enough and the axles were bottoming out into the trailer.

What was the trailer rated for? How many lugs on each wheel?

If they put 3500lb springs on a 5200lb axle, I'm with ya. But, if you put 5200lb springs on a 3500lb axle, you're destined for more damage somewhere down the road.

Trailer rated for 7,000 lbs. @ axles - 3,500 lbs. each. Original springs bottomed out SO badly that it bent up underside of frame with LESS THAN max load! I did a weight test - appx 300 lbs under max total weight. Even moving at less than 10mph, camera showed axles/U-bolts slamming into frame in driveway. I replaced with 5,200 springs - does NOT mean I'll be trying to haul 10,000 lbs.! But now I don't have to worry about further damage to the underside of trailer.

Been using trailers for decades, as many here have. I don't overload trailers!

 

[C. Amick]

Yes, I believe it is made from mobile home axles.

 

[C. Amick]

There are 5 lugs on each wheel.

 

[C. Amick]

There are 5 lugs and the axle measures around 3-inches in diameter. The single spring leaf actually measures 0.9 inches in thickness at the axle. I assume that they are 3,500 lb. axles? What is the heaviest weight you would want to haul?

 

[C. Amick]

The axle measured 3-inches in diameter and the spring measured 0.9 in. or about 7/8 in. So it looks like I have at last 6,000 lb. axles and 3,000 lb. springs (according to etrailer link). I have not weighed the trailer, but it is pretty heavy. So, a 2 ton load might be doable? Don't think I can pull more than that.

 

[C. Amick]

The added information by others makes that seem correct.

 

[C. Amick]

Thanks for all the replies. I need to rework the electric brakes. Would you put brakes on both axles or just the front one?

 

[jon f mn]

Not over 3500 on those or they will bend.

 

[jon f mn]

Put brakes on all the axles as those brakes are not that great to start with. However, many states it is legal to have brakes on just one axle on trailers up to 7,000 pounds. Make sure you check the axle close and get the right brakes and hubs.

 

[C. Amick]

Okay, thanks.