chevy 63 swap on an 80?

[js93cruiser]

so...i've been thinking, the bushings in my rear lca's are going bad, and i hate it how my shocks hang so low....the rocks love them, anyway thinking about putting 3/4 ton chevy leafs in the back of my lx, it would make the rear axle look like way less of a cluster fxxx, and i would have more stability and more flex...opinions???

 

[silverhorse]

definitely the cheapest route for good flex on a rig. But if your after more flex, why not just lengthen your existing set-up and add heims , re-do the low hung shocks and LCA brackets. or do the leaf springs with a traction bar.
Whatever makes you happy. Anything can be made to work. It's all personnal preference.

 

[alkaline747trio]

Are you sure about more out of the rear end on this thing? Plus you'll have axle wrap you didn't have before. Plus a rougher ride. I just don't see anything wrong with the rear....and leaf springs would be extreme backwards engineering.

 

[D'Animal]

I agree.

I just don't see anything wrong with the rear....and leaf springs would be extreme backwards engineering.

Kinda like taking a FZJ engine out and putting a F135.

 

[Grizzard]

I am actually looking into doing the same thing only taking it as step further by finding a cheap 1 ton chevy and swaping the axles with leaves and all over to my fj80. I am gonna build alittle vw diesel powered Samurai and want to use the fj80 axles in it. So I wanna make my 80 a tow rig by sticking 1 ton running gear in it..

 

[matt60/80]

The 80 already has a 1 ton axle.

 

[js93cruiser]

definitely the cheapest route for good flex on a rig. But if your after more flex, why not just lengthen your existing set-up and add heims , re-do the low hung shocks and LCA brackets. or do the leaf springs with a traction bar.
Whatever makes you happy. Anything can be made to work. It's all personnal preference.

by the time you buy the heims, and the d.o.m, etc... its going to cost alot...i'm getting the leafs for free, and its going to be 120 bucks for the swap parts....not to mention i wont bend any lca's again, i'm going to do it, i just wanted some feed back...and btw i wont have a ton of wrap du to using the 3/4 ton leafs

 

[Nay]

I think it is an excellent idea, because you'll pick up a lot of stability to complement your 3-link while substantially simplifying your rear suspension.

Rear leafs/front coils is a proven suspension setup for full size rigs - I hope to see you do it as I think you will be able to run a 6" lift with total stability with this setup on an 80

 

[silverhorse]

I have never heard anyone using the 3/4 ton springs only 1/2 ton. There is usually a big difference in the spring pack thickness between the two. ... I agree coil/leaves are a good combo as I use this set-up currently on my trail rig. Go for it..

 

[yOHda]

the only downsides i can see to this swap is 63s have hardly any lift, therefore it's possible you could be running a 2 or 3" block just to get the desired height you want out of them. secondly, 63s have a lot of rear overhang, youll be dragging them on everything and could potentially back up into a rock and bend a spring(done it). also french your hangers or your leaf spring hangars will be just as low as your lca brackets are. results on an 80 may vary this is based off my experience with them on my runner...im linking it this winter btw.


for $120 are you thinking about using SKYS chevy kit....if so...those hangars are rock magnets.

 

[js93cruiser]

the only downsides i can see to this swap is 63s have hardly any lift, therefore it's possible you could be running a 2 or 3" block just to get the desired height you want out of them. secondly, 63s have a lot of rear overhang, youll be dragging them on everything and could potentially back up into a rock and bend a spring(done it). also french your hangers or your leaf spring hangars will be just as low as your lca brackets are. results on an 80 may vary this is based off my experience with them on my runner...im linking it this winter btw.


for $120 are you thinking about using SKYS chevy kit....if so...those hangars are rock magnets.

i'm getting all my brackets from ruff stuff, an if i bend a spring i have quite a few spares, i doubt i will, but the simplicity would be amazing...

 

[Adam R]

Why don't you sleeve the LCA's. That way you won't ever bend them again. You are going to a lot of work to modify something that already works very well.

Adam

 

[Nay]

the only downsides i can see to this swap is 63s have hardly any lift, therefore it's possible you could be running a 2 or 3" block just to get the desired height you want out of them. secondly, 63s have a lot of rear overhang, youll be dragging them on everything and could potentially back up into a rock and bend a spring(done it). also french your hangers or your leaf spring hangars will be just as low as your lca brackets are. results on an 80 may vary this is based off my experience with them on my runner...im linking it this winter btw.


for $120 are you thinking about using SKYS chevy kit....if so...those hangars are rock magnets.

Take a look at the frame and axle position for a spring over - I think you are looking at 6" of lift with a flat spring. The LCA frame mounts are already frame magnets, it won't get any worse.

Departure angle is a potential issue, but with the leafs he gains the ability to go to a bigger lift with good stability - the flat leafs provide excellent roll axis for a taller lift just for starters.

This will be interesting - a rear leaf / front coil 3-link is a suspension design that moves the stabilizing factors from the front of the 80 (limited motion radius arms) to the rear leafs without reintroducing the lack of flex. The very flexy rear suspension of the stock 80 is moved up front with the 3-link. The rear leaf springs provide progressive load bearing characteristics, which the 80 really needs.

As I have said, a lot of fullsize rigs run rear leaf/front coil suspensions for this reason. There is no reason I can think of why this shouldn't work on the 80 - many people here have a philosophical bias against leaf springs and no question they have their drawbacks. But from a design perspective, a 5 link suspension running at a steep link angle is far from optimal, especially when that suspension has to care for variable cargo loads, and leaf springs on a rear suspension really only have to care for load and lateral positioning of the axle. Coil springs also have their limits and in this case the design premise is very sound.

As to how it will work? Somebody finally has to pull the trigger to test it.

 

[Brian Macgyver]

I think it's nuts. The most flex is gained with a 4-link coil spring system. Even Heep made the change, and for a reason. Leaf springs just don't flex that well. Coils have the greatest flexibility as to length and stiffness. Handling is greatly improved. Coil spring trucks with four-link control handle much better and have far greater modification flexibility. Read as "can we lift it? Yes we can!" Coils give the best handling and lift flexibility.
I helped to design the suspension system that moved the Ford full-size from leaf to coil/4-link suspension. I was 1/2 of a team that designed a bolt-in suspension for Ford full-size trucks from the early '90's and older to remove the leaf spring suspension, and replace it with a height-adjustable 4-link coil spring system. It was a huge improvement in handling. Ford later adopted our system. Or rather, they stole it! They literally bought one of our prototypes and put it into production before we patented it.
We made the change from wooden wheels to steel, and then to alloys over the years. Then we made alloys common enough to be realitively inexpensive. So why would we return to wooden wheels? Would you?
Why would you screw with what works better, after it has already been invented and perfected? Would you willingly return to wooden wheels, or leaf springs? I wouldn't!

 

[yoopercharged]

Leaf springs are good for simplicity and ruggedness. There is little tuning other than oversteer and pinion angle. Not much to screw up with leafs, but it can be done. It's the easy button. If you're not good at suspension design or tuning, leafs are a great way to go.

 

[yOHda]

actually there is a lot of tuning that can go into a leaf pack. look at the RUF(rears up front) thread on pirate. ive rebuilt my front and rear leaf packs quite a few times to get the lift and performance i want out of them. i started with flat leaves that flexed great on the trail but had horrible sway and brake dive onroad. my current pack in the front is comprised of 3 toy leafs, a cut down ford f150 leaf, and 2 more cut down toy leafs below that. my rear leafs start with a f150 main leaf, then 3 toy leafs cut down in 3" shorter lengths, with a chevy leaf on top of the pack for an antiwrap leaf(cut off after ubolt plate). the truck rides great on the highway and crushes all 4 bumpstops on the trail.

pinion angle can be set by where you burn your spring perches in. doesnt have much to do with the springs themselves.

anyway, all you can do is try it and see if it accomplishes what you want it to. the rears of the these trucks seem to work very well, i just dont see 3/4t springs being a better setup. but get to work and prove me wrong.

 

[js93cruiser]

actually there is a lot of tuning that can go into a leaf pack. look at the RUF(rears up front) thread on pirate. ive rebuilt my front and rear leaf packs quite a few times to get the lift and performance i want out of them. i started with flat leaves that flexed great on the trail but had horrible sway and brake dive onroad. my current pack in the front is comprised of 3 toy leafs, a cut down ford f150 leaf, and 2 more cut down toy leafs below that. my rear leafs start with a f150 main leaf, then 3 toy leafs cut down in 3" shorter lengths, with a chevy leaf on top of the pack for an antiwrap leaf(cut off after ubolt plate). the truck rides great on the highway and crushes all 4 bumpstops on the trail.

pinion angle can be set by where you burn your spring perches in. doesnt have much to do with the springs themselves.

anyway, all you can do is try it and see if it accomplishes what you want it to. the rears of the these trucks seem to work very well, i just dont see 3/4t springs being a better setup. but get to work and prove me wrong.

i'm using the 3/4 ton springs because my truck is a lard ass, and next pay check i'm going to get to work and get it done!!

 

[Nay]

Even Heep made the change

That's true, but look around you if you live someplace where there are a lot of lifted 4x4's. You will find Cherokees all over the place at 6"-7" of lift (those pesky rear leaf springs), but the quad coil Jeeps tend to stay lower at around 4" due to suspension dynamics issues.

You might remember a number of 80 series owners dropped from 6" lifts to 4" not that long ago on the basis that the taller lift didn't feel stable. That sounds very familiar to me to what I just said above.

This pic is a rear leaf/front 3-link XJ that has run the Hammers and other "Best of the West" trails. No rear coil conversion, no triangulated 4-link.

Remember, the OP is not designing a highway rig - he wants maximum trail performance with greater simplicity and he already has a front 3-link. Definitely a moment.

 

[Brunt Force Trauma]

any update on this idea?

 

[js93cruiser]

any update on this idea?

yes, i'll be doing a writeup on it within 2 weeks