Leaf Springs - how many leaves to remove?

[Esteban]

The OEM leaf spring arrangement shows only one leaf spanning all the way to the shackles. Eddy the Eagle studied the failed derated springs and specified that my needs were best served by having two leaves span the compete distance. See picture.

I approve, the ride is very smooth. Total of five leaves.

Patrolling over potholes,
L60Boerne

Actually the OEM spring package has 2 principal leaves spanning all the way, with one of them surrounding the other. From what I've seen in all these years, the Patrol is the only one with 2 principal leaves.

Just a general question. When looking at the shackle in the posted picture, should they lean towards the front, lean towards the rear or be vertical? All when the patrol is unladen.

I just read somewhere that they should be at 7 O'clock. I assume that means the bottom of the shackle leaning towards the front slightly.

In your picture the shackles are leaning slightly to the rear.

The picture of L60Boerne shows the shackle between 6 & 7 o'clock. I copied the following diagram from the Service Manual, and superimposed a clock (actually reversing the image to match the clock) At normal loaded condition the shackle is a little past 7 o'clock.

Rear Leaf-Spring Package.jpg

[L60Boerne]

Peter60 and Esteban,

Very Interesting Esteban so the OEM leaf spring arrangement did have two leaves extending the full length. I am certain Presidio Patrol and the White Patrol booth had replacement springs when I bought them. At the end of the day they are military spec vehicles. The second full length spring must address expected loads. I'd be interested to know if the FJ40 had the same OEM configuration....it should.

First, you know by now...I know not what what or why I do. So I have no clue as to the ramifications of the position of my shackles....Second, the shackles pictured deliver a 2" lift...would that change anything? Lastly, if they are in a problematic position now is the time....next two weeks ......to get them fixed before our Chihuanhuan Desert roll.

So ...as usual I need advice like Chapstick in Aspen.

Patrolling when possible,
L60Boerne

[Peter60]

Thanks Esteban. Magic information provided. I'm reworking my current springs and I will be interested in seeing what angle they have.

"2 principal leaves spanning all the way". I read somewhere that they were designed for the military. I guess if the main spring broke the vehicle could still be driven.

I think that L60Boerno picture MUST have 2 principal springs. The first spring is to the shackle bolt (you can't really see that). The second spring wraps around the first spring but just 'floats' there - you can see that clearly.

[L60Boerne]

Peter60, You have described the two main springs correctly. One wraps, the second spans but no attachment. I feared a rough ride but that is not the case.
Have a good day down there,
L60Boerne

[RiverPatrol]

So I have no clue as to the ramifications of the position of my shackles....Second, the shackles pictured deliver a 2" lift...would that change anything? Lastly, if they are in a problematic position now is the time....next two weeks ......to get them fixed before our Chihuanhuan Desert roll.

So ...as usual I need advice like Chapstick in Aspen.

Patrolling when possible,
L60Boerne

I don't think the position is an indication of anything wrong or potential to go wrong. New springs will settle, changing the angle of the shackles. Drive it a bit and see. What I do see that my be a concern is the shackle pins. There should be large flat washers under the castle bolt and the bolt should only be hand tight with a cotter pin keeping it's position. If the bolts are too tight the shackles can't flex, making for a hard ride and wearing out parts prematurely. I can't tell from this picture if the washers and cotter pins are there.

[L60Boerne]

ThanksRiverPatrol and Esteban and well everyone that helps me every week,

Seeing those little details like cotter pins is important and helpful. I will check tomorrow when I take it back to Eddy's lair for the attachment of the two missing vacuum hoses he thought were unnecessary to reconnect running from the distributor to the air filter housing.

Eddy the Eagle and King Kong Craig spent 8 man hours last Saturday trying to get the clutch to work in the red patrol to no avail. They will remove the transmission and try again next weekend.

Thank you all again, rebuilding Patrols can not be done without you,

L60Boerne

[Peter60]

The results on how many springs to remove.

Firstly the result. Stunning! Such a smooth ride. My previous springs were just solid. Every little bump in the road resulted in the Patrol vibrating up and down. It was as though I had flat spots on the tyres. If I now jump up and down on the back of the Patrol you can feel the springs move - doing what they should.

Recommendation: Yes you should do it, but read on first.

So what I did was to remove 4 leaves from my 9 leaf pack. Leaves 1,3,4,and 6. I kept the leaves that had rebound clips and of course springs 8 and 9 that bolt onto the chassis. I didn't cut the rebound clips down, just in case I need to add some leaves back in. Once painted they look OK.

My patrol was a heavy duty LWB flat tray Patrol with a H260 diff. I have only worked on the rear springs.

I pulled the springs apart, and cleaned them up. I then used

IMG_5919.JPG

to etch the springs. However I may have used the wrong etching as later I read the label and steel wasn't mentioned.

Then I added some Polyurethane sheet between each spring - in the centre around the centreing bolt. I purchased a roll 150mm wide by 500mm long with a Thickness of 1mm from China via eBay. I cut this up into pieces about 70mm wide (the width of a spring) by 150mm long and drilled a 10mm hole in the middle.

You might be able to see the polyurethane in this image.

IMG_5926.JPG

IMG_5932.JPG

Finally I painted them black.

IMG_5936.JPG

I also put in new shackle plates, shackle pins and all new rubber bushes. These were necessary in my case, but may not really add to the ride. I'll post another entry about this later.

I plan to do exactly the same to my front springs when I have time.

I have done a little 4WDing and the springs seemed fine.

I haven't tested it with a load, but for my case I'm sure it will be fine. If not I may add back a couple of springs.

Just a couple of other thing that you may find useful.

For the centering bolt I used M8 (8mm) Hex Socket Cup Head bolts The round head fitted perfectly into the location holes on the diff. The length was no of leaves x thickness of leaves + 5mm (for Polyurethane) + 10mm for the bolt nut.

When assembling the springs I used a longer bolt (any head, as long as it fitted) to pull the springs together, then used G clamps to hold the springs and then replaced the bolt with the correct length bolt.

And finally when I assembled the axles to the springs I found the the U bolts needed a 'spacer' so the nuts had thread to engage. The was because, of course, leaves were missing and the nuts didn't have any thread to tighten.

I think the massive improvement in ride and comfort was because I cleaned the springs up and placed polyurethane in between the leaves to reduce friction. It may have not been necessary to remove as many leaves as I did.

Again the result. Fantastic. While it took some effort (say 2 days) and $50 of parts it was well worth it.

[Esteban]

Excellent and thorough description! A must read with great tips. Congratulations!

As you said, probably one of the biggest improvements was the addition of the polyurethane sheets between the leaves, so they are separated a little bit and reducing friction a lot. The new paint on the leaves definitely helped as well.

Thanks!