Parabolic springs?

Joined
Jan 30, 2010
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SK Canada
spring over axle. gives about 6 inches of lift but rides much smoother and flexes better. way more work to do it well.

there are shackles that will work with the narrow shackle hanger and the wide spring. they have a small offset to match the width at each end. you still need to change the solid end spring hanger though if you want the wider spring. 60 springs are a little longer i believe so have better flex than the 40 hence the suggestion even though the 60 is heavier. i have custom made (alcan) 60 springs that are flatter than stock to do my spring over so i don’t get crazy lift but i get the nice flexy spring. it’s pretty tall still compared to my other 40 with the OME springs

here’s the difference if you can make it out. blue is SOA
2822D653-C391-4F98-BD53-E51464866276.jpeg
 
Joined
Jan 17, 2007
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Finland
Once upon a time somebody did sell parabolic springs for the fj40.
The stock springs are pretty squishy.
Just remove a leaf from the spring pack and try that. Do you have stock shackles or aftermarket longer ones. How tight are your shackle bolts?. If you want lift just do a SOA. The only way to fly. Haha.

BD554332-9C3E-4435-91FA-C2B3B45F95C2.jpeg
 
Joined
Oct 31, 2020
Messages
49
Location
Pennsylvania
So maybe March 2023? That might work for me.
spring over axle. gives about 6 inches of lift but rides much smoother and flexes better. way more work to do it well.

there are shackles that will work with the narrow shackle hanger and the wide spring. they have a small offset to match the width at each end. you still need to change the solid end spring hanger though if you want the wider spring. 60 springs are a little longer i believe so have better flex than the 40 hence the suggestion even though the 60 is heavier. i have custom made (alcan) 60 springs that are flatter than stock to do my spring over so i don’t get crazy lift but i get the nice flexy spring. it’s pretty tall still compared to my other 40 with the OME springs

here’s the difference if you can make it out. blue is SOAView attachment 3160493
Is it difficult to change the solid spring hanger to fit the 60 series spring?
 
Joined
Apr 7, 2021
Messages
620
Location
Minnesota
I always wonder what people's tolerance and expectations are when they buy an old vehicle.

There are so many inherent issues with the FJ40 compared to a modern vehicle in every category except for simplicity.


Some broad generalizations:

Old vehicles drive like crap
Ride like crap
Handle like crap.
Steering geometry blows.
Suspension geometry is horrific
Noise mitigation is nonexistent.
They are extremely inefficient.
Have less than ideal climate controls.
Ergonomics suck.
Aerodynamics suck.
Emissions are less than ideal.
Safety was still a four letter word in the 70's, and I'd have to check to see if it even existed in the 50's when these things were designed. 😆

It's like when guys but a ZO6 Corvette and wonder why they're pissing blood on a long day behind the wheel.

With that said, I love driving old crap. BUT, I would rather take my 2021 work pickup on a 1000 mile road trip. My commute is 12 miles, and I drive the 40 daily.

If I won the lottery, I don't think I would have a personal vehicle newer than 2000.
 
Joined
Oct 31, 2020
Messages
49
Location
Pennsylvania
I always wonder what people's tolerance and expectations are when they buy an old vehicle.

There are so many inherent issues with the FJ40 compared to a modern vehicle in every category except for simplicity.


Some broad generalizations:

Old vehicles drive like crap
Ride like crap
Handle like crap.
Steering geometry blows.
Suspension geometry is horrific
Noise mitigation is nonexistent.
They are extremely inefficient.
Have less than ideal climate controls.
Ergonomics suck.
Aerodynamics suck.
Emissions are less than ideal.
Safety was still a four letter word in the 70's, and I'd have to check to see if it even existed in the 50's when these things were designed. 😆

It's like when guys but a ZO6 Corvette and wonder why they're pissing blood on a long day behind the wheel.

With that said, I love driving old crap. BUT, I would rather take my 2021 work pickup on a 1000 mile road trip. My commute is 12 miles, and I drive the 40 daily.

If I won the lottery, I don't think I would have a personal vehicle newer than 2000.
Hey, good broad generalizations. I agree with all of them. Right, I'd never drive an "old" vehicle 1000 miles. I only use my 40 for short trips and have another vehicle when I want to get somewhere far, fast, be comfortable, be safe and want to save a lot of gas. But old vehicles advantages:

1: I dig them.
2: uhhh, let's see.... I'm striking out here.
 
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But old vehicles advantages:

1: I dig them.
2: uhhh, let's see.... I'm striking out here.


Here's a good one. Go buy a brand new pickup. That's only $100k now.... 😡 It is in a state of decay. Immediately.

Go buy an old POS anything. Easily over $100k to get to new condition. Up until you're done, it'll be constantly improving. I'll be happy to stop pouring buckets of money into my project, but I'll be sad when it turns the corner going back to decaying.

Advantage, old vehicle.
 
Joined
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Pennsylvania
Here's a good one. Go buy a brand new pickup. That's only $100k now.... 😡 It is in a state of decay. Immediately.

Go buy an old POS anything. Easily over $100k to get to new condition. Up until you're done, it'll be constantly improving. I'll be happy to stop pouring buckets of money into my project, but I'll be sad when it turns the corner going back to decaying.

Advantage, old vehicle.
An excellent analysis for advantage old vehicle. Another option: buy POS. Just get it into running condition. Sure, it is now in a state of decay, but really how much more decay could there be? Drive it until something breaks, fix. Eventually if you want, you can probably sell POS for more than you paid, with minimal time/effort/money added to it.
 
Joined
Apr 2, 2008
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60 series leaves are wider i believe though so you’d still need to change hangers

In about ‘93 I took the top leaf off a set of 60 rear springs. I then rotated the second leaf end for end so that the military wrap would be at the back and put the top 2 leaves from my 40 packs on top of it. I shortened the 60 leaf to match the 40 pack’s length and drilled a new centre whole to also match the 40 pack.

Getting to the point. The 40 and 60 leaves were the same width. I even later used the 60 top leaf and 45 leaves to make spring packs for a trailer, and mounted them using 40 spring hangers.

Point being is that those 1980s 60 series leaves are still the same width as 40 series.

I’ve been told mine rides well for a 90” wheelbase… which could be related to the 4 essentially full length leaves on the top of each pack. However, it could also be because of the extra weight from the 1/8” steel 1/4 tub. The rear axle has roughly 1150 kg on it and the front 950 kg. Which is why the shocks are also likely complete wrong.
 
Joined
Oct 31, 2020
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Pennsylvania
Good stuff, thanks! Good point too about the weight of your 40 helping with ride. Didn't consider this, but PO replaced tub with aluminum, so now my 40 is probably a couple hundred pounds lighter than stock.
 
Joined
Oct 31, 2020
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Pennsylvania
I emailed Terrain Tamer got a response from Cruiser Brothers who apparently are the American distributor. Reportedly they ARE working on a parabolic spring for the 40, but don't expect it until late 2023. Don't think I'll wait that long.
 
Joined
Oct 31, 2020
Messages
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Pennsylvania
getting a leaf spring with extra length (also means moving spring hangers can help with harsh ride. first check what springs you have. small number of heavy leafs will make a harsh ride. logger number of thinner leads tends to be smoother and you can more easily take a leaf or two out of the pack. before doing that check shackle angle and make sure shackles are moving freely. remember it’s still a 40 with a short wheel base. it’ll always be a rougher ride than a cadillac but i had bds springs which rattled my teeth. changes to OME and it made a huge difference. some guys have used chevy 1/2 ton springs in the back but you need to move hangers to do that
Just wanting to clarify: You said "changes" to OME. Did you mean changed? Or did you mean modifying the OME springs by taking out a leaf?
 

pjohnson

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You should read up on a couple of Nolen's @wngrog build threads. He's done real world research on 40 suspensions.
 
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Nowhere Nebraska

I don't think they make any for the 40 series anymore, but I bought a set off the classifieds here at least a decade ago. I put them on my '78 and have been running them ever since. Some people complained of QC problems, but I've been really happy with the ride. They are starting to show their age so if TT comes out with them for the 40 I'll grab a set.
 

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