Parabolic springs?

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1971 FJ 40: I need to replace the rear springs. I would like a softer, more compliant ride. I understand that parabolic springs can provide that. Any thoughts? Where to buy?
 
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If you want a soft ride, buy a Cadillac.
Finding tapered springs that fit an FJ 40 might be a problem.
Might look into adapting coils.
 
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Oh yeah, an old Cadillac is on my wish list! I also see online that some are shortening the bottom leaf or two and report a less harsh ride. Thoughts?
 

Skreddy

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1971 FJ 40: I need to replace the rear springs. I would like a softer, more compliant ride. I understand that parabolic springs can provide that. Any thoughts? Where to buy?
Lifted or non lifted? Replacing shock as as well? What’s on it now? Softer on paved roads, gravel roads or rock crawling?
 
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Wish I knew exactly the answers, but I think:
1: I want softer more compliant ride on paved roads. No plans for rock crawling.
2: I think original leaf springs, I do believe it has been mildly lifted.
3: Oversize tires
4: I expect I'll want to replace shocks to optimize ride.
 

pjohnson

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Pics would be a big help.
 
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four link or five link suspension modifications. Coil over shocks.
 
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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. larger number of thinner leafs 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. changed 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
 
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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
Thanks! Right, short wheel base will always be rougher ride, but since I have to change out some very badly worn out springs, thought I'd at least try to reduce the harshness. I don't want to move hangers, OME sounds like an option with maybe a leaf removed.
 

pbgbottle

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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.
 

Downey

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one of the common mistake guys make is using the same stiffness/valving of shock on the rear as they use on the front. You have extremely heavy engine on front end, empty bed on rear end, sooooo stiff rear shocks gives you a buck board, rear end bounces up in the air on every bump in the road, and you catch it in the back of your neck. Racer Ivan Stewart use to say “I hope my rear bumper drags every inch of the Baja 1000”.
 
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one of the common mistake guys make is using the same stiffness/valving of shock on the rear as they use on the front. You have extremely heavy engine on front end, empty bed on rear end, sooooo stiff rear shocks gives you a buck board, rear end bounces up in the air on every bump in the road, and you catch it in the back of your neck. Racer Ivan Stewart use to say “I hope my rear bumper drags every inch of the Baja 1000”.
Thanks for information about shocks, I was definitely going to look into options on shocks to give the least amount of harshness possible. I'd be willing to bet that is part of what I've been feeling.
 
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60 series leaves are wider i believe though so you’d still need to change hangers
Interesting idea about 60 series. I wouldn't mind getting shackles to fit. Do you know if the 60 series would be designed to support the same load? I wouldn't want to buy 60's and find they are more harsh.
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.
Stock springs are pretty squishy? So, less harsh than some other options? I don't know about my shackles, if they are stock or not, I'm not home now, but maybe I'll post some pictures, and then ask you guys to tell me what I actually have. I don't know how tight the shackle bolts are, I guess that could make a difference too?
 
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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.
"If you want lift just do a SOA"??? What is SOA?
 

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