Scrapping the leaves, going with coils......maybe.

[1bad40]

I'm trying to talk myself out of trying to put coils or coil overs under my FJ just because I know its alot of work, alot of geometry and planning, and alot of money but I think it would be awesome. I would like more articulation than what leave springs would offer. Which can be had by using a revolver type shackle but I heard they're not good for daily drivers because they flex TOO much taking off, slowing down, and turning corners. In reality I'm building this thing as a daily driver and a trail rig, not a rock Crawler. I don't need a perfect 1000 RTI I just think coils would be sweet. What are your thoughts? Anyone have pics of coils under their FJs? Or any tips about doing it?

Could calling Geico really save you 15% or more on your car insurance? Do fat girls like fries?

 

[John Smith]

In reality I'm building this thing as a daily driver and a trail rig, not a rock Crawler.

Then don't waste your time and money on coils. A 4 inch lift or SOA is all most 40s need to be a great trail rig and daily driver.

 

[74fj40]

I do agree with john smith. BUT, a very easy and common swap for these things is swapping coils, coil bucks, and radius arms from an 80 series onto the front axle. Then just SOA rear.

 

[1bad40]

I do agree with john smith. BUT, a very easy and common swap for these things is swapping coils, coil bucks, and radius arms from an 80 series onto the front axle. Then just SOA rear.

I like that idea! The big reason for wanting coils in the front was because of how far the frame sticks forward of the grill. If I go with coils I can lengthen the wheel base without lengthening the frame.

Could calling Geico really save you 15% or more on your car insurance? Do fat girls like fries?

 

[1bad40]

After pondering your idea I came up with a couple questions. Why do you recommend an 80 series specifically? And what does this swap do for the ride height?

Could calling Geico really save you 15% or more on your car insurance? Do fat girls like fries?

 

[yzftaco]

Are you going to be doing"Hardcore" trails? As in are you going to be doing obstacles that you most likely are going to thrash your rig on?


If yes than coils would be a good idea.. (only real advantage of linking is that you can do harder trails)

If not than stick with the leaf springs.. you can do some really hard trails with leafs and it's all about K.I.S.S. when it comes to building your rig..

Leafs can be tuned also.. take a leaf out or put one in to get the ride you want.. Ive seen rigs with leafsprings that have crazy flex.. But at some point you're sacrificing the on road drive-ability also..

 

[1bad40]

Scratch the coil idea, I read an article in a Jan 09 issue of Four Wheeler (yeah I keep them that long) about a low buck leaf spring solution. If I can get this much flex from my leafs I wont need coils. Check this thing out!

"throughout the history of 4x4s only a few earned the right to be called lengendary. The original FJ40 Toyota Land Cruiser is one of the few" - TLC Icon

 

[camcruiser13]

Second the notion. No need for coils on trail/ dd. I get plenty of flex ou of my stock springs soa. Coils is way too much work for the stuff you'll be doing. Imho

 

[hicruise55]

Plus adding lots more to break, for what I consider not THAT much improvement

K.I.S.S

 

[1bad40]

And not to mention, after following all the coil sprung rigs down the exact same trail, I can drive right on by while they stop to hook their sway bars back up before entering the highway.

"throughout the history of 4x4s only a few earned the right to be called lengendary. The original FJ40 Toyota Land Cruiser is one of the few" - TLC Icon

 

[lcwizard]

The more articulation thing is a myth. The travel restrictions of any suspension are a result of their
initial design.
1. The stock FJ40 was , primarily because of factory shock postions and selections,designed for about
6" of travel. The '75 and later gained a little rear axle advantage by moving the lower shock position
down but no improvement to the front.
2. The stock springs were designed with heavy spring rates and minimal deflection hampering
articulation.
3. The front and rear pinion angles can only accommodate so much droop before causing issues with the
stock , low angle u-joints.

To maximize articulation in a 40 you should cut and turn the front end, taller shock towers. A spring designed for maximum travel.
If you shackle reverse up front, a longer slip and depending on what running gear you have , consider a double cardan rear drive shaft.
If you are looking for a high angle ujoint that easily adapts to the 40 yokes, the FJ80 front driveshaft
uses 45 deg. yoke/u-joint setups. The 40 series use 24~27 deg units

http://www.man-a-fre.com/pa4/P4155566b.jpg

http://www.man-a-fre.com/pa4/P4155580b.jpg

 

[1bad40]

To maximize articulation in a 40 you should cut and turn the front end,

What do you mean by "cut and turn" are you referring to cutting the spring perches and rotating the pinion upward? I was going to that anyway when I perform the SOA.

"throughout the history of 4x4s only a few earned the right to be called lengendary. The original FJ40 Toyota Land Cruiser is one of the few" - TLC Icon

 

[lcwizard]

That refers to cutting the knuckle balls free and rotating them so your pinion has a
more accommodating ( upward ) pitch while maintaining the caster angles you need to
have good road manners. This is generally necessary over 4" lift. Personally I do it to mine
after any lift if I'm looking for a lot of droop. I personally like about 6 ~8 deg of upward angle,
depending on lift, with a caster angle of about 2~4 deg. positive

 

[Mark W]

I max out 13-14 inch travel shocks in both directions on both ends of my leave sprung '40. How much more do you need? If I was to take the shocks off I would get more. Heck I max them out with simple axle compression and droop up front, even without articulation.

And the suggestion of putting '80 series suspension under the front end...'80s are not exactly know for a lot of travel up front. A LOT of work to not even equal what you can easily do with leaves.

Mark...

 

[1bad40]

That refers to cutting the knuckle balls free and rotating them so your pinion has a
more accommodating ( upward ) pitch while maintaining the caster angles you need to
have good road manners. This is generally necessary over 4" lift. Personally I do it to mine
after any lift if I'm looking for a lot of droop. I personally like about 6 ~8 deg of upward angle,
depending on lift, with a caster angle of about 2~4 deg. positive

I would like some more info on this topic. I understand how to pitch the pinion up 6°-8° by the placement of the new perches, that's a "no brainer". However I am not familiar with the FJ40 front knuckles (this is my first solid axle 4x4) what does cutting the knuckles entail? I might be able to figure it out if I was home and had the axle on the bench but lets say I'm going at it blind.

"throughout the history of 4x4s only a few earned the right to be called lengendary. The original FJ40 Toyota Land Cruiser is one of the few" - TLC Icon

 

[subzali]

From the tech links at the top of the forum. That and the FJ40 FAQ will have most of what you need to know.
Cutting and Turning

Just cutting the perches off and turning them will really screw up your caster angle.