Softening the Suspension on an M101CDN Trailer

[BrettDez]

Hello everyone!
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I purchased my M101CDN from a fellow Expo member here and have since converted it to a Spring Over Axle setup with 35s. The trailer height is now perfect and gives great clearance for getting over rocks while crawling with the trailer in tow!
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I do have one issue though. The suspension is still pretty stiff! While moving along the trail, the trailer can very easily turn bumps into "jumps" as it hops about. And this is still at slow speeds of only 5 to 10mph! So for the trailer's sake and for the sake of all my gear inside I would like to soften the ride up.
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Goal is to soften the ride up but not completly redesign the suspension as my fabricating skills are limited and with a big trip coming up I don't want to get in over my head.
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My initial thought is to simply remove some of the leafs from the leaf pack. My experience is with coil spring suspensions....never really done anything with leaf springs before. Does anyone know which leafs I should remove or how many? I don't want to spend all the effort to remove too few or the wrong ones to have no effect and at the same time I don't want to remove too much and now cause an issue with the suspension not dealing with the weight. Trailer probably weighs around 1200-1400 fully loaded.
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So, any ideas on what leafs and how many to remove? Small ones? Big ones? Every other one? A group together?
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And also...I hate to sound incapable, but how exactly do I remove leafs from the overall pack? I'd rather ask now than curse about trying to figure it out on my own while bleeding from the head!
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I have also heard that you can swap out the leaf springs entirely to a Suzuki Samurai OME kit. Has anyone actually done this? Was it effective? And what kit speciffically was used?
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Here is a picture of the leaf pack that I took while doing the spring over axle conversion:

 

[brentbba]

Subscribed!

I'd love to know too! Several comments from those following me the past two weekend outings about the 'jumps' and 'hops' as you say above on anything from rocky roads at higher speeds and up/down rock gardens where the truck would crawl right over and the trailer would go airborne. I've always know the trailer did this, even now with another 200 lbs of tent on top! Can't afford the air suspension replacement AT offers. Super nice, but out of my price range until I hit the lotto jackpot. Logic would tell me a couple of the small leafs, but do not know. Mine has the SOA sitting on 33's.

 

[brentbba]

Brett - saw hollenbach's comment about the suzuki samui leaf springs. I knew that part, but not anyone that's done it. There's a Yahoo group for M101CDN owners. Haven't been on there in awhile, but remember seeing discussions on these leaf springs being a replacement for OEM and somewhat softer. Don't recall if anyone had actually done the swap.

 

[quantum73]

Same comment really, I have heard of it but never seen it done. I am also in the Yahoo! group but haven't seen much (if any) discussion on this. Would definitely be interested in a write-up as it would be great to get a little more flex in mine...

On a related note. Once you do the SOA, it is easy to weld a couple shock tabs onto the axle, replace the shocks with a longer and higher-quality model, and gain a good amount of travel in the process (with a more favorable angle as well). This would work well with a softer spring pack and more flex.

EDIT: Updated with pics

 

[BrettDez]

Well, I may be the guinea pig on this one, haha!

Problem is with the big trip coming up, I can't afford many mistakes. Add in that I am more of a bolt-on modifier than a fabricator. :-(

I found an older post with the username "Overland" that stated he removed 2 of the smaller leafs. He wasn't sure if that helped all that much or if his tire pressure did more. Nothing very definitive.

I don't want to invest in the suzuki samurai leafs at this point without any actual success known of.

I am considering removing up to 3 leafs, just not sure which 3 of the pack.

 

[brentbba]

Brett,

Some info I found searching on the Yahoo Group from 2008. Old Man Emu part number. He did say in another post on the thread that the ride was somewhat softer, but he hadn't loaded up his trailer yet. Replied to one of the threads asking him how much softer. Let's see if we get a longer term update...like six years if he's still on that group! I'd love to soften the ride to, but 95% of my 2000 mile trek at the end of the month is on road and freeway so no need to rush on either leaf removal or replacement.

The spring part number I used is CS012FA...and it say's 1.25"-1.50" of
lift for the Samurai. The shackles I used were regular off-the-shelf
long shackles. I drilled the top hole to work with the stock shackle
hanger bolt and used 9/16" diameter spring bolts on the bottom (spring
eye end). The sleeves for the spring eyes need a little bit of enlarging
to use them with the bigger bolts but I think it will be okay.
The good part is that I'm still spring-under so I don't have the strange
angle of the shocks but I do not have any installed yet....soon.

 

[faulco]

On the British sankey trailer I'm sure they remove leafs 3-5-7. Not sure on this one though.

Sent from my C6903 using Tapatalk

 

[brentbba]

Quick internet search on the OME part number - still available. $70 range, couldn't tell if that was each, per pair, etc. tho! Sierra Expedtions was one of the suppliers, so a quick call to Will would probably get that answered!

 

[UK4X4]

In Venezuela I couldn't get lift kits for my rear leaf spring suspension , so I messed with the leafs, adding as required

Looking a that lift pack you have probably no movement.

Leaf technology is pretty simple.

From a non techy view all leaf springs graduate in size

From the photo you have a whole bunch !

It's difficult to see on the photo, looks to me like 3 almost full length ones then the staggered length and then some short ones.

If that's correct I d remove one of the almost full length ones and all the small ones at the bottom.

Grind down each leaf reassemble using red waterproof grease, be generous

Before you start measure the movement on X side with and without your own weight. Do the above and re measure

Adjust to suit, you'll probably find you want to remove more shorter ones to get the flexibility you want.

Th trailer was designed to run at full speed over weighted with amo, not some chairs and a cooler.

Suzi and old jeeps are good swap ins as the pack is physically longer and designed for less weight, but requires welding or creative bolting and cost.

Large leaves allow more flex than short, the short add weight capacity

 

[shakotankei]

Following this thread. Not really much to contribute except I'm setup pretty similar to brentbba minus the SOA. I run my trailer tires at a pretty low pressure and spring under I don't find it to be too jumpy. Interested in what you decide to do as I'm planning on lifting the trailer maybe SOA and extending the fenders pretty soon.

 

[quantum73]

An excerpt from an M101 group reply.

"Outstanding! It's still spring UNDER and has plenty of lift for 33" tires. It's almost too soft, if you can believe that! I do have the Old Man Emu extra leaf but have not installed it because I don't want it higher.
I just used cheap NAPA shocks to dampen the spring and they too have been just fine."

Awesome feedback. I may head this route with the new springs and a new Dexter axle...

EDIT: As a side note, the ARB application book shows HEAVY LOAD (125-200LBS) SPRING 1.25" (2) CS013FA as an option. 1/4" less lift but heavier duty. They also list the bushing kit and other parts for the lift that may or may not be needed for this application.

http://www.arbusa.com/uploads/PDF/accessorizeYourRig/suzukiSamurai.pdf

Leaf Spring Properties CS012FA http://www.sierraexpeditions.com/index.php?l=product_detail&p=1326
Stack Height (mm) # of Leaves Eye Dia. (mm) Weight (kg) Primary Free Camber (mm) Spring Rate(Ibf/in) (N/mm)
24.4 4 30(front) - 40(rear) 8.1 125 207 / 36.3

Leaf Spring Properties CS013FA http://www.sierraexpeditions.com/index.php?l=product_detail&p=1329
Stack Height (mm) # of Leaves Eye Dia. (mm) Weight (kg) Primary Free Camber (mm) Spring Rate (Ibf/in) (N/mm)
30.0 5 30(front) - 40(rear) 10.4 125 247 / 27.9

Bushings...
http://www.sierraexpeditions.com/index.php?l=product_detail&p=3470

 

[BrettDez]

Excellent news! If his setup was a little too soft, then I am willing to bet the CS013FA heavier duty leaf pack you found would be just right.

The install doesn't look as straightforward though....

I am curious based on his description...

Can't we just reuse the stock shackles? Unbolt the military leaf pack and just bolt in the new leaf pack directly in place and call it a day?

 

[quantum73]

Excellent news! If his setup was a little too soft, then I am willing to bet the CS013FA heavier duty leaf pack you found would be just right.

The install doesn't look as straightforward though....

I am curious based on his description...

Can't we just reuse the stock shackles? Unbolt the military leaf pack and just bolt in the new leaf pack directly in place and call it a day?

I am thinking the exact same thing on the shackles and leafs. I think we can use the stock shackles, OME bushings (possibly re-size ID), and the OME CS013FA (which appears to be a pair for ~$82). It may be heavier but it is still going to be a lot better than the stock pack. As for the bushing holes, at worst they may need to be reamed out a little. I also have a set of Land Cruiser bushings that have graphite built-in that should also be a direct replacement. I bought them a couple years back from Spectre Offroad for the stock leafs but never got around to installing them...

 

[BrettDez]

Secondary concern...

Does the guy on the Yahoo Group have his trailer modified with extra weight and an RTT on top? I can imagine if we went too soft by accident due to weight differences between our trailers and his, we could cause the trailer to be very wobbly with people in the tent and lean too much in offcamber situations.

 

[java]

Following along here:

I have a trailer with very soft springs and shocks. It moves A LOT if I climb around in the bed of the trailer. Does fine on roads, doesn't sway, but the shocks seem to really help. Off road it leans around and bounces still, but nothing terrible. I do carry dirt bikes in it which makes it a bit top heavy.

Im in the process of building a new mini trailer. I went with 500lb capacity each trailer springs, They are ~29" long. Im hoping they will be about the same.

Maybe that info helps with the very soft spring ideas.