Leaf springs

Jeff Dodgen

Explorer
I have a camper project going on and while I am working on the axle and suspension I noticed the leaves are pretty dang rusty and figured I would replace them while I was in there. Went to the local supply place and couldn't find the exact replacement. Called the supplier listed on the product and now I am more confused than before. I have a 20"ish spring length with four leaves. The axles appears to be a 3500lb'er. The unsprung weight of the vehicle is right around 1200lbs dry, and we add about 250lbs when we go on a trip. Would a three leaf spring rated at 2000lbs do the job? I wouldn't mind a cushier ride but don't want to lose any height. I don't want a harder ride either. Thanks, and sorry for the elementary question...I have a nicely modified TJ and only somewhat understand coil springs.:sombrero:
 

Jeff Dodgen

Explorer
The longer spring theory was what I thought too, but the guy I spoke with said otherwise. I think I may run the longer spring...too many people agree with us to not do it. When you went to the longer spring, did you gain ANY lift...and did it allow for more uptravel as well? Just trying to keep in mind what tire size I am going to be able to run on here. Uptravel would affect this.
 

Jeff Dodgen

Explorer
Post some pictures so we can see what you are doing.
The longer spring idea is a good one.

I can next week. I hope to get back to work on it Monday. I am at the fire department today and Sunday. Tomorrow I have to haul butt home to swap a transmission by 11AM. Monday *should* be suspension day on my trailer.

Just for explanation I bought an 8' box Starcraft pop up off Craigslist and I am modifying it somewhat. The goal is a 30" tire on a 15X7 rim. The springs have a good bit of rust so I was just gonna replace them...and while doing that I was gonna see what my best option is. The camper is around 1200lbs and ultimately I would like it to have a little softer ride with 1" of lift. If a 25"ish spring will do this over the 20"ish I have now then that would be great! The trailer guy told me I need 3500lb springs to match my 3500lb trailer. Seems to be I should be matching a spring to the trailer weight, not what the axle is rated for. Is this correct?
 

jeep-N-montero

Expedition Leader
The longer spring theory was what I thought too, but the guy I spoke with said otherwise. I think I may run the longer spring...too many people agree with us to not do it. When you went to the longer spring, did you gain ANY lift...and did it allow for more uptravel as well? Just trying to keep in mind what tire size I am going to be able to run on here. Uptravel would affect this.

Was this guy you spoke with a salesperson or an actual builder? I have been doing suspension stuff for 13 years and grew up around my dad's work trailers over 25 years ago, so I have learned a few things. As for suspension travel, small trailers see very little of it due to only having one axle and lighter weight, as suspension travel is typically the reaction to an opposite physical force. Basically think of your Jeep, when the left front wheel raises over a rock the right rear also gets pushed up, trailers do not do this because there is not another axle to cause this. In reference to tire size, my trailer has more clearance with just 31's than my Jeep does with 35's, so go as small as possible on tires to cut down on weight and wind resistance as well as cost.
 

jeep-N-montero

Expedition Leader
I can next week. I hope to get back to work on it Monday. I am at the fire department today and Sunday. Tomorrow I have to haul butt home to swap a transmission by 11AM. Monday *should* be suspension day on my trailer.

Just for explanation I bought an 8' box Starcraft pop up off Craigslist and I am modifying it somewhat. The goal is a 30" tire on a 15X7 rim. The springs have a good bit of rust so I was just gonna replace them...and while doing that I was gonna see what my best option is. The camper is around 1200lbs and ultimately I would like it to have a little softer ride with 1" of lift. If a 25"ish spring will do this over the 20"ish I have now then that would be great! The trailer guy told me I need 3500lb springs to match my 3500lb trailer. Seems to be I should be matching a spring to the trailer weight, not what the axle is rated for. Is this correct?

There are many folks who run a 2k spring with a 3500 lb axle, a softer spring gives a better ride while the 3500 lb axle gives a larger bearing setup and takes abuse better. And it sounds like this "trailer guy" is an idiot without any real experience.
 

Jeff Dodgen

Explorer
I was thinking the guy was more sales and less tech. So is it safe to say a 2000 lb 25" long spring will be a good option for me?
 

OGL

Observer
Just for explanation I bought an 8' box Starcraft pop up off Craigslist and I am modifying it somewhat. The goal is a 30" tire on a 15X7 rim.

Ooh! Now I really want to see pics! I swapped the original torsion axle for leaf springs and added shocks to my Starcraft camper. That alone made for a much smoother ride and gave me exactly the lift I was looking for. But I didn't go nearly as radical with wheels.
 

RugerTrailer

The Trailer Guy
As for suspension travel, small trailers see very little of it due to only having one axle and lighter weight, as suspension travel is typically the reaction to an opposite physical force.

I agree. I wheel my trailer hard and only have about 4 inches of up travel before my tires hit my fenders.

For a one inch lift there is a simple solution. Cut a piece of 1" tube, weld it to your trailer frame where your leafs mount. It's a little more complicated but I'm assuming you have some suspension/fab experience. I can post pictures if I'm not making any sense.
 

jeep-N-montero

Expedition Leader
I agree. I wheel my trailer hard and only have about 4 inches of up travel before my tires hit my fenders.

For a one inch lift there is a simple solution. Cut a piece of 1" tube, weld it to your trailer frame where your leafs mount. It's a little more complicated but I'm assuming you have some suspension/fab experience. I can post pictures if I'm not making any sense.

With such light side loading he should be fine welding a longer mount on I would think, especially if there is a center gusset. Also depends if they are slipper springs or double-eye, if double-eye he can simply bolt on longer shackles. I hope the OP isn't getting a headache from all of this.
 

Jeff Dodgen

Explorer
No worry, the headache is from being 30 minutes away from finishing a 48 hour shift at the fire department. To answer some questions, yes, I have fab experience and already have a longer spring mount to replace the old one. The springs are eye/eye, but the shackles are already the longer ones that I saw offered at the supply store. I thought about making a longer one but was unsure how long it can be and still be safe. As I said, I am putting in a longer front leaf mount, do I need to lengthen the shackles as well for any type of suspension geometry reasons? I thought about taking the shackles and welding a steel square tube between the two...like a Jeep aftermarket shackle. Probably just easier to put the spacer between the frame and mount.

Washboard FS roads are primarily all this camper will see. Departure angle is my only concern as some of the roads we travel have small mounds for erosion control and would cause the tail to drag when crossing. I simply want more height for this reason as well as because the tow vehicle is a TJ with 37" Krawlers with 4" of lift and D60/D44. I kinda think the camper should ride somewhat level behind me without a ghey 14" drop hitch. :sombrero: I will try to get some pics up next week. Its nothing fancy or really "expo" worthy, just something that was actually requested by the wife to make camping in the woods a little easier. When the wife says she wants a cool trailer to tow behind a built TJ that she loves as much as me, I kinda jump on the opportunity.:Wow1::ylsmoke:
 

RugerTrailer

The Trailer Guy
No worry, the headache is from being 30 minutes away from finishing a 48 hour shift at the fire department. To answer some questions, yes, I have fab experience and already have a longer spring mount to replace the old one. The springs are eye/eye, but the shackles are already the longer ones that I saw offered at the supply store. I thought about making a longer one but was unsure how long it can be and still be safe. As I said, I am putting in a longer front leaf mount, do I need to lengthen the shackles as well for any type of suspension geometry reasons? I thought about taking the shackles and welding a steel square tube between the two...like a Jeep aftermarket shackle. Probably just easier to put the spacer between the frame and mount.

Washboard FS roads are primarily all this camper will see. Departure angle is my only concern as some of the roads we travel have small mounds for erosion control and would cause the tail to drag when crossing. I simply want more height for this reason as well as because the tow vehicle is a TJ with 37" Krawlers with 4" of lift and D60/D44. I kinda think the camper should ride somewhat level behind me without a ghey 14" drop hitch. :sombrero: I will try to get some pics up next week. Its nothing fancy or really "expo" worthy, just something that was actually requested by the wife to make camping in the woods a little easier. When the wife says she wants a cool trailer to tow behind a built TJ that she loves as much as me, I kinda jump on the opportunity.:Wow1::ylsmoke:

I agree it would be easier to put a spacer between the frame and the mount, and you will get exactly 1" of lift. I've done it both ways and it's easier this way.
 

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