4 link rear - FJ40 - if you have done it - would you again? (1 Viewer)

[Splash]

I searched and read every thread with "link" in the title.

Considering replacing my Alcan rear leaf springs with 4 link. Inclined to keep leaf springs up front.

I am installing new axle housings so now would be the time. It would be professionally done by Predator Mike so high quality but expensive for sure. Just hoping to hear from some who have done it to what degree it improved the off road capabilities of their FJ40. Would you do it again?

I generally run Rubicon and Fordyce.

Below are some particulars on the rig although not sure they make any difference in this conversation.

475 HP Ford 393
3 Speed Auto Trans
Atlas Transfer
Spidertrax Axles
ARBs
35s currently maybe going to 37s (still needs to go under 7' garage door - stupid design mistake on house)

Thanks in advance.

 

[76FJ40]

I have a three-link setup on the rear of my 40 and SOA in the front. The articulation is great as you can see from my avatar but it's too flexy for street use. I would definitely do it again for an off road only 40.

 

[SuperBuickGuy]

yes, I've done it and I would do it to yours too. 475 hp and more importantly, the torque will wrap soft springs which causes broken u-joints and all sorts of other handling issues. Be sure you understand instant center and how it affects a 4 link rig to get the best possible result.

 

[SuperBuickGuy]

I have a three-link setup on the rear of my 40 and SOA in the front. The articulation is great as you can see from my avatar but it's too flexy for street use. I would definitely do it again for an off road only 40.

I drive my linked '40 everywhere - why do you say 'offroad only'?

 

[76FJ40]

I drive my linked '40 everywhere - why do you say 'offroad only'?

The suspension is too soft and flexy so the on road handling is not exactly precise.

 

[mr jits]

I have and would do it again. 4 link rear, SOA front. On road manners are better (by far) than when it was leaf spring only and offroad it's proven to work better than the SOA setup (and is saving me u-joints). The only thing I need to add currently is a swaybar for the rear.

 

[Splash]

Thanks guys. Appreciate the input. What did you do, if anything, to address sagging in the rear when loaded with gear for a trip? Considering
coil over shocks.

 

[SuperBuickGuy]

The suspension is too soft and flexy so the on road handling is not exactly precise.

I tied my lower arms together with a softish sway bar.... still has full travel but there is resistance to leaning - it's also my only sway bar on the vehicle....

 

[SuperBuickGuy]

Thanks guys. Appreciate the input. What did you do, if anything, to address sagging in the rear when loaded with gear for a trip? Considering
coil over shocks.

I have coils not coil overs - but I use a dual rate spring, which is the same as using a tender on a coilover set up. It took a bit to find the right rate (and I have 8 springs to prove this) but once I did, I've not had a problem. On mine, I have front coils out of a F350 van (on the rear); the front have coilovers with tenders. The hardest part of finding coils was the spring length (and even that is wrong now, but I did a work-around)

 

[mr jits]

Thanks guys. Appreciate the input. What did you do, if anything, to address sagging in the rear when loaded with gear for a trip? Considering
coil over shocks.

I also have a coil setup in the rear. In my avatar the truck is on a stock FJ40 spring pack in front and zj upcountry progressive coils (fronts) in the rear. I've since removed two leaves from the front pack (maybe too much, I think my springs are bowing) and moved to stock zj coils (fronts again) for the rear. The truck now sits almost two inches lower than the avatar photo.
I like the offroad manners of the rear coils, but do think the spring rate is too light for my use.

 

[Mace]

Link it and run bags if the loaded weight is a major concern for you.

My 40s been linked for about 14 years. I love it..

 

[Mace]

Years ago there was a kit that ran supplemental bags on a set of coilovers. Really neat concept but it never caught on.


edit, they might still be available.

Coil-over Bag & Brackets By Universal Air - UniversalAir.com

 

[Rock40]

Definitely not "offroad use only" but you need the whole package; links, correctly sized bumpstops, correct spring rates and a swaybar. I have thousands of highway miles on my linked 40 and it's great, far better than leaf springs

 

[69LC]

What do you all think about building links with one end having a standard through-bolt rubber or poly bushing and the other ends having a ford radius arm style rag joint? The rag joint would allow infinite rotation and there would be no heim squeak or wear.

 

[mr jits]

I went with ballistic joints on my lowers and heims on the uppers. So far, no real noticeable noise. As soon as I can start to hear the uppers, I'll replace them with new ones.
I don't think I'd go with a bushing, and I'm not a fan of the ford style joint.

What do you all think about building links with one end having a standard through-bolt rubber or poly bushing and the other ends having a ford radius arm style rag joint? The rag joint would allow infinite rotation and there would be no heim squeak or wear.

 

[74fj40]

Maybe consider factory jk control arm bushings. They are very soft and the longevity is unreal.

Also, look at the duroflex joints from metal clock. It’s similar to a Johnny joint but it’s full sealed off with rubber.

 

[Mace]

Bushings on one end are fine, but the Ford radius arm studs are not the best idea.

 

[cruisermatt]

Land Rovers use that style bushing as well on the frame side. Not a fan. Too sloppy.

 

[lucky 13]

I would definitely do it again.