Can anybody help me to undersatand,
when I need adjustable track bar for lifted
rear end - 2' inch, 3', 4'?
The truck is 1998 4runner.
I derived rather simple formula:
transverse axle shift~
(amount of lift)^2/(2*Length of trackbar)
It gives roughly 1/2' of axle shift at 3' lift.
The problem I see is adjustable track bar alone doesnt
help much, because in that case axle will be shifted
with fully loaded rear end.
The way I see it is I must keep track bar as close to
horizon as I can. Only in that case small height variances
doest affect axle position too much.
I have to lower the position of track bar, that means
some welding is necessary.

So, does anybody know the numbers, what level of lift can be done without trackbar issues, or how large can be
rear axle shift to keep ride safe?

 

all i know is on my 98 4runner - after i put on my ome 891 coils, i got 3 full inches of lift, and without the adjustable track bar every time id hit a bump or whatever, the rear would not trac straight and thus try to move the back end to the right.

After installing the sonoran steel adjustable trac bar, i adjusted it to exactly what his specs say to, and the thing tracks dead straight now over bumps

 

Thank you, j-man.
I want to lift ~ 2.5-3', about the same as you.
Maybe I just by adjustable bar from Steve as you did.
Did you change rear shocks to longer ones, or running stock?

 

Well, you really should get an adjustable track bar for any size lift as it's relatively important to keep the rear axle centered.
You are correct in your assumption that the track bar should be as close to parallel as possible, for the reason you mentioned and others.

Still there is a right and wrong way to get the rear track bar parallel after a lift.
One can lower the frame end or raise the axle end.
Almost all of the 4Runner lift vendors make a "drop bracket" that lowers the frame end (there is only one that I've seen that makes a bracket that raises the axle end).
Lower the frame end is the wrong way to level the track bar.
Doing that lowers the MC and that's not a good thing.
You want to raise the frame end which raises the MC bringing the MC close to the COG.

Funny thing. I'm from a Jeep background (heavy duty rock crawling).
A little over a year ago when I first started thinging about getting a 4Runner, I started poking around a bit, looking to see what the after market supplies were like and it looked as though there was a large aftermarket following for Toyotas (which there is). Also some of the forums (like this one) looked pretty good, at first glance.
Now that I have a 4Ruuner and have looked a lot more in depth, I've come to realize that the after market following is actually pretty much behind the times, compared to the Jeep TJ's..

Even the crappiest Jeep TJ lift kit manf. provides a rear track bar reloction bracket the raises the axle end. I don't think that I've ever seen one for TJ's the lower the frame end.

Suspension lift "kits" are, for the most part, incomplete for Toyotas.
It's seldom that bumpstop extensions, for instance, are included and, from being on several forums now for close to a year, with the execption of one of the "hard core" forums, the vast majority of people posting don't seem to have any idea when bumpstops extensions are needed, what bumpstops do, etc.

And don't even get me on the subjct of leaf springs





Fred

 

Thank you for your advise, Fred.
I just didn't get the difference between right
and wrong way to level the track bar.
Why it is so important to raise the axle end,
it is not clear to me.
I will think about it.

 

i got the bilstien HD - i think theyre longer than stock by and inch or 2 - its whatever Wheelers offroad gave me when i bought the 891's. They feel tight and right.

 

The track bar mounting points deteming the MC (Moment Center, use to be called RC, Roll Center).
You want the MC to be as close, vertically, to the COG (Center of Gravity) as possibly.
The further away the MC is from the COG, the more roll (body roll as some would call it) the vehicle will experience in turns and the more unstable (wanting to flop on it's side so that you can inspect the underside easier ), it'll be in off camber areas.
The MC is a point half way (vertical measurement) between the two mounting points of the track bar.
By lowering the frame end of the track bar, you're lowering the MC.
By raising the axle end of the track bar, you're raising the MC.

Ever watch a NASCAR race ?
They'll mention often about a "track bar adjustment" and if you watch when the cars pit, you'll ofter see one of the pit crew insert what looks kinda like a jack rod, down through the rear window and one end or the other (drivers side or passenger side) and then give the rod a turn or two.
What they're doing is either raising one end of the track bar or lowering one end of it, depending on what they want to accomplish, handling wise.





Fred

 

Thank you again, Fred.
Now I got it. But I also never seen axle end raise bracket
for 4runner. If it is so important, I think I have to try make it by myself. If I'll do it, I will keep stock
track bar and just raise axle end for some certain amount of lift.
j-man, Steve has very informative page concerning 4runner
rear shocks: http://www.sonoransteel.com/rear_shocks.html
It seems like bilsteins are about the same length as stock.
The longer ones are OME and landcruiser 80.
My goal is to fit LC80 shocks, since they are 3.5 inchs longer than stock.