what spring rates

[half k cruiser]

So the more I drive the wife's new GX the more I dislike the rear airbags. The overall ride of the rig is nice down the road, but certain things trigger the rear to unload side to side and I don't care for it. Couple that with the fact that I know the rears will eventually fail, and I'm beginning to look into replacement springs.

I have already gone down the road of heavily modified off road vehicle. My 80 series will go just about anywhere I point it. While I really enjoy it, this truck is my wifes daily driver and our families vacation vehicle. That said, it needs to stay comfortable yet capable.

It seems from the research I have done staying at 2'' of lift or under will keep you out of replacing the UCA's. I am also concerned about the ride. One of the things I enjoy about a Lexus is the smooth ride, and I would like to retain that as much as possible.

So i'm interested to hear from the group. What are you guys running for spring / shock combo's . If you have spring rate numbers that would be helpful. Also, what size tire's are you guys running without rubbing ?

 

[6LCJ7]

I will have Bilstein 5100's all the way around and Toytech 112620 and Wheeler's Offroad T12 coils going on this weekend hopefully.

The guy at Wheeler's said that would be about +1.5" all around using lowest perch on the fronts. It's her daily and we don't need a ton of lift.

The T12 are supposed to be 12% firmer than what the spring would have been if there was a spring. (I think.) I think the fronts are 620 lb springs, and I think read that stock is around 600. Not sure though.

 

[co4wheel]

UCAs make a huge difference. Adding caster makes it track so much better. Also there is a lack of room for the spring with even a mild lift. I had one oem UCA hitting the spring in full droop. It would happen on one bump in my office parking lot and on a trail often. SPC UCA solved both issues. I could have beat the folded part a little better on the one that hit. But it was worth the money to buy the spc as mine where already seeping at the ball joint.

 

[co4wheel]

I will have Bilstein 5100's all the way around and Toytech 112620 and Wheeler's Offroad T12 coils going on this weekend hopefully.

The guy at Wheeler's said that would be about +1.5" all around using lowest perch on the fronts. It's her daily and we don't need a ton of lift.

The T12 are supposed to be 12% firmer than what the spring would have been if there was a spring. (I think.) I think the fronts are 620 lb springs, and I think read that stock is around 600. Not sure though.

That's my setup. Your on a good track. I did just raise the front to second from the bottom. But the advice you got is accurate.

 

[half k cruiser]

UCAs make a huge difference. Adding caster makes it track so much better. Also there is a lack of room for the spring with even a mild lift. I had one oem UCA hitting the spring in full droop. It would happen on one bump in my office parking lot and on a trail often. SPC UCA solved both issues. I could have beat the folded part a little better on the one that hit. But it was worth the money to buy the spc as mine where already seeping at the ball joint.

So you are adding caster with the UCA ? Do you have a link to what your using ?

 

[GXO]

UCAs allow for the corrected caster to go back to stock (+3.28) from adding lift. As you add lift you lose caster. If your UCA can't account for the lost angle, you can't correct it back to stock and the steering will be quick and tend to wander with micro corrections. If you get caster back, that goes away. If you run bigger tires and can go passed stock caster (+3.5-4) you can actually slow down the steering even more and it won't feel as "darty" with a lift and big tires.

 

[co4wheel]

Caster is a good thing. The only downside to added caster is heavier steering. I have just under 5 and it feels great. Added caster also increases camber while cornering which is also a good thing.

 

[co4wheel]

Specialty Products Company 25480 Upper Control Arm for Toyota 4Runner and FJ - Pair

Search that on Amazon or go to MetalTech website. He had a sale recently. Call and ask for then15% off code with free shipping.

 

[half k cruiser]

UCAs allow for the corrected caster to go back to stock (+3.28) from adding lift. As you add lift you lose caster. If your UCA can't account for the lost angle, you can't correct it back to stock and the steering will be quick and tend to wander with micro corrections. If you get caster back, that goes away. If you run bigger tires and can go passed stock caster (+3.5-4) you can actually slow down the steering even more and it won't feel as "darty" with a lift and big tires.

I should have mentioned I am familiar with the affects of caster increase/decrease. I am used to correcting on a solid front axle and am still figuring out how this all works with the IFS.

 

[GXO]

I am running +5.1 with my 35s and it is taking a lot of the flakey steering out of the clevis and heim tie rods I added

 

[co4wheel]

I should have mentioned I am familiar with the affects of caster increase/decrease. I am used to correcting on a solid front axle and am still figuring out how this all works with the IFS.

The SPC UCA has been made with additional caster built in and a adjustable upper ball joint to fine tune it. Go to their website and pull up the instructions. It looks more complicated but makes perfect sense with the parts in your hands.