Topic: What causes Brake Dive?

[mmessier2]

I lifted my 4runner 4" and added 33" tires on it.  As expected, I have a fair amount of dive to the right when I brake hard while traveling over 40mph.  What causes this?  Will going to crossover steering eliminate it?

[MiniSimp]

Crossover will eliminate that.
Did you remove your torque rod?
If you didn't cut off the torque rod brackets put a stiff shock in there instead.

[yotaweelr]

springs get longer as they flatten, draglink does not.

[yotaweelr]

try braking hard without gripping the wheel, let it spin in your hands, your truck will stay straight as long as there is no resistance in the column.

[Rocksurfer]

I'd have to call the torque rod a myth, sure under hard braking without it your axle will twist some but I had my torque rod on my 84 lifted and it would pull hard to the right. A nice steering dampner in place of it makes for a cool adjustable substitute since under braking it will bottom out and stop the twist. You've got bump-steer plain and simple, get a crossover or an adjustable steering link and it'll be gone.

[yotaweelr]

thats because a torque rod doesn't get longer either. you can try a steering stabilizer for a torque rod. I have read on pirate that some have had good luck with that. Histeer will fix your problem with only 4" of lift, as the front end compresses, the distance between the passenger side steering arm and the pitman change very little. and with gas charged shocks it will be even less noticeable. it will slow the movement down.

[79coyotefrg]

i use a gas charged rear shock  for my torque rod,  works great,  if i try to shove the pedal through the floor it will pull a little  but not bad,  and i'd rather it go right  when hitting the brakes hard than going left

[Wermz84]

,  and i'd rather it go right  when hitting the brakes hard than going left

Ain't that the truth!!  Much rather possibly deal with people going in the same direction than comming straight at me.. 

[yotaweelr]

a death grip while letting off the brakes will make it go left, I almost went into on coming traffic with a newer expedition coming at me a couple years ago. a explorer cut me off, i was merging into a turn lane at a light, and he decided to make a quick left hand jet into the lane i was in without looking. I was already stopping, and then i had to stop even quicker.

[Cheesemaker]

There could be a slight possibility of a brake caliper grabbing harder than the other!  That could make it pull/dive to one side!

[yotaweelr]

I bet you all he has to do is put the stock flat springs back on, even without a track bar, it will not do it. I garauntee it isn't a caliper problem lol.

[Willy Mammoth]

The torque rod is there to keep the same distance between the axle and the steering box. By doing this it will keep the truck from steering when you lunge on the brakes or go over a bump. Extend the bracket on the dif of frame so the torque rod is at the same angle as the push pull steering rod and you will have no more problems. I guarantee it.

Or better yet, trash the J arm and push pull steering and get the high steer, you will be glad you did.

[ZUK]

I lifted my 4runner 4" and added 33" tires on it.  As expected, I have a fair amount of dive to the right when I brake hard while traveling over 40mph.  What causes this?  Will going to crossover steering eliminate it?

Brake dive is very pronounced with a rear mounted shackle and soft positive arched leaf packs.  One solution is to move the shackle to the front(frame horn ends).....but don't do that if you still have the J arm.....bump steer will be out of this world. ZUK
I missed the part about the "dive to the right"....like the others have said, that's happens when the torque rod is removed. Cross-over will cure that.