How much lift to consider

[Do Over]

‘69 FJ40 w/31” tires. After four years of work, the mechanical, electrical and body work is almost complete. As a “flat lander” I won’t be rock crawling but no doubt will be in corn and bean fields and obviously on hard surface roads. The truck currently has (PO) 4” Rough Country springs and shocks and no camber wedges. What lift would look good and ride and handle diecently? Right now it is very stiff.

Thanks for the input.

 

[charliemeyer007]

The differentials hit first. That much lift usually requires some steering correction measures. Um its a tractor - rough ride is a result of design, leaf springs, short wheel base.

 

[pb4ugo]

Yea, Columbus is pretty flat but an hour or 2 it can get hilly or more. I would think 31" tires and a 4" lift makes the tires look small and the wheelwell openings look awkward. A lift can effect steering geometry, and can be corrected. Your welcome to come down to Cincinnati and ride or drive my 40 with a 4" Skyjackers and 33's. I think it drives and rides great for a FJ40. 2" or 3" work too. There are a lot of choices out there. Shocks can help too.

 

[Do Over]

The differentials hit first. That much lift usually requires some steering correction measures. Um its a tractor - rough ride is a result of design, leaf springs, short wheel base.

I totally understand the tractor thing. I grew up with MF, Oliver and Cockshutt and tricycle wheels. I understand rough. Right now I have 9” clearance.

 

[Do Over]

Yea, Columbus is pretty flat but an hour or 2 it can get hilly or more. I would think 31" tires and a 4" lift makes the tires look small and the wheelwell openings look awkward. A lift can effect steering geometry, and can be corrected. You’re may take you up on thatwelcome to come down to Cincinnati and ride or drive my 40 with a 4" Skyjackers and 33's. I think it drives and rides great for a FJ40. 2" or 3" work too. There are a lot of choices out there. Shocks can help too.
View attachment 3732262

I may take you up on that. I agree the 31’s look a little small with the current setup.

 

[pb4ugo]

It's hard to see your shackle angle. You might consider removing a leaf to soften things up. You'll want good bushings and check your caster angle with a cheap angle finder on level ground. Positive caster helps handling. Put the angle finder on the bottoms trunion bearing cap. Dont use the studs iron nuts. If it has a 4" lift it probably needs 4 to 6 degree shims. Mine needed 6*.

 

[Do Over]

It's hard to see your shackle angle. You might consider removing a leaf to soften things up. You'll want good bushings and check your caster angle with a cheap angle finder on level ground. Positive caster helps handling. Put the angle finder on the bottoms trunion bearing cap. Dont use the studs iron nuts. If it has a 4" lift it probably needs 4 to 6 degree shims. Mine needed 6*.

On level concrete the shackle is approximately 5*.

 

[franklin40]

i’ve done 2.5 inch lift and 33s. they look good and don’t rub. i went with OME bilstein combo. i found that the stiffer spring actually needed a stiffer shock to minimize the rebound bounce. what i realized was it made it feel rough because you’d actually bounce twice for every one bump. the stiffer shock modulated the stiff spring. i also took a leaf out to help soften the ride. one other item to consider in the brand is how many leafs you have and how thick they are. my OME i believe had seven thin leaves. i had BDS on a previous 40 with only 4 thick leaves and they were terrible. way too stiff for a daily driver. as mentioned above make sure you’ve got good shackle angle and the parts aren’t tightened
too much or they be stiff. overall height of your springs should be about how much tire you want so you clear your diffs from obstacles. keep it as low as you can while achieving that so your centre of gravity doesn’t go up too much either.

 

[archie73]

I’ll wade in here and give my experience- Get bigger tires first. Second, play with the air pressure. I have 35” with 4” of lift. I give up any thoughts of it being a sports car, so I’m conservative in the corners. Flip side is my ride is soft. I think I run 28psi. A set of 33” tires should give similar results and fill out the lift. 35’s will likely rub a bit.

And get the recommended shims to correct your steering. Makes a big difference. Aluminum shims are readily available, but there is good logic that says steel is more reliable.

 

[aging fleet]

I may take you up on that. I agree the 31’s look a little small with the current setup.

You're welcome to take a look at mine as well. I'm on OME 2.5" springs, Bilstein shocks, and 33" tires.

 

[AJFJ40]

So is a 2.5" skyjacker enough for 33's with cutout rear fenders and flares? Thanks

 

[White Stripe]

So is a 2.5" skyjacker enough for 33's with cutout rear fenders and flares? Thanks

Yes but you will have to adjust your bump stops.

 

[1MOA]

Go OME 2.5" med heavy and Bilstein 5100 series shocks. Replace EVERYTHING to include all bushings.
once you build it literally take it out and wheel it till it maxes out on travel and it will loosen up amazingly well. That is what I run and I am very happy with the ride both on and offroad.
Another thing you should try is running less air in your tires. It makes a huge difference and doesn't cost anything. If you are running quality off road tires that are 10 ply you are not going to hurt your handling running them less than the max inflation under a 3500 lb truck .