Matt16

Hmm, that goes against what nearly everyone else with 12.5" wide tires says. Maybe you have a freak idler arm, but my bushings are bad already after 9mo., and I DON'T beat on my truck and I run 10.5" tires. The idler arm, is really quite a weak link.

Mic09dcsm

So because something the suspension components rest on they'll break? And because a tire is bigger an idler arm is going to take a and say F U? I have 35x12.5's and my idler arm is chilling, it has new bolts and a support rod for the added Rancho steering stabilizer but thats it.

Trustyrusty

If everyone thought that putting a coffee can exhaust tip on your car made it go faster, would that mean its true? I hate to be a dick but the internet is full of two types of people. Examples below

Web Wheelers-Can't do anything right, constantly does sloppy installs of quality products, and or talks about said products that he does not own. Like people who don't have body lifts saying they suck. And vice versa

Real Wheelers-Been there done it more times than you can count, has real eye witness viewing of what works and what doesn't.

I hate to break it to you but 75% of the people on the internet fall into the first catergory, they are just web wheelers and thing you have to have a SAS, 35's, Longfields, Twin Cases, And dual lockers to go through a small rain puddle, and if they haven't done it their "friend" or this guy who knew a guys who's cousin did it. Most people don't run a 12.5" wide tire cause its basically taboo to do so. Do it. And if it breaks, its not like you can't fix it. I've had no breakages, and I will eventually run 35's until it would be more cost effective to swap in that solid axle that I've got. IF I don't break it, then I have no reason to swap. Hell the stock tires on IFS trucks are almost 9" wide, so if you can break it with near stock parts, your doing somethin' wrong, or your driving a chevy. I've seen a IFS axle stand up to 4WD burnouts with 38" Boggers and a V8... Granted I wouldn't be one bit suprised if they broke things, but it can do it. Its Toyota Tough.

Matt16

Sorry mate, I didn't understand a single sentence there, except you have a 35x12.5R15.

The stiff Rancho steering stabilizer, theoretically should make it even tougher on the idler arm.

With no steering stabilizer, the tire catches a rut and transmits all the force through the steering knuckle, rod ends, idler, relay rod, pitman arm, steering box then steering wheel where you feel the feedback from the rut. The idler arm is stronger than YOU, so your shoulders suffer, not the idler arm.

Now, with a strong steering stabilizer, the relay rod is held firm, so the idler bushing takes quite a hit as the relay rod is forced upward by the rods ends upon hitting bump hard. I urge you to lock the steering, jack up your truck, grab the passengers side tire, and push it back and forth. If your idler arm kicks up, and I'll bet it will, your bushings are shot.

I'm not questioning your manhood saying you don't drive your hard, so cool it a little, all I'm saying is that my stock height, stock tire size, properly aligned 4Runner ate a set of bushings in 9 months. I have friend (Jay351 on yotatech) with a lift and 33x12.5s and his idler arm bushings, sometimes the full arm even, is toast after one wheeling trip. This leads me to the logical conclusion that fatter tires and a lift kills idler arms. This view is shared by many people on this board who aren't really considered "web wheelers".

Trustyrusty

I ain't po'd dude, its all good. But what I'm saying is it doesn't make that big of a difference, I just have had no problems with my tire size, and rather rough driving style. Also come to think of it what you just said about the steering stabilizer, I DID actually blow mine up.. After that landing escapade, it was leaking fluid pretty bad.. I on the other hand have completely stock IFS, I bought a body lift instead of the Chevy 63" swap and BJ spacers to keep my front suspension in stock form, since stock=strongest with this breed of IFS. I will be glad to report when I start having problems, but I think with the way I drive and 35's breaking ring gears will be the most common problem for me. I've talked with Jay 'bout the Idler arm problem somewhat.. Not really sure why his eats bushings so bad.. I may get brass bushing for mine even though it hasn't failed me yet *Knock on wood* But I do hope you'll agree with me MANY people on this board and others have the attitude that anything over 33's+IFS= Have never ran 35's and IFS or even seen it, all they have is hype, negative hype actually.. Oh and what that other guy meant to say is he runs 35's with a rancho steering stabilizer and has no problems. Atleast I think thats what he said?

PS- On another note, I read your review on your Aussie Locker and I've decided to purchase it over a lock right so thanks for doing a write up.

stormin94

This is helpful, but as far as I know, my 4Runner wanders a little already, so maybe it's already toast, but it's been that way since I've owned it (28,000 miles).l

Took it out on some pretty easy trails today, and what a difference the new tires make. It's a little harder on the clutch with the larger tires, and 4.30 gearing, but other than that, it did great. It's quite a bit smoother too. LOTS of traction, and a little better view over the hood, so I can get my wheels placed better. One of the down sides, other than the clutch, and gearing, is the rubbing when it flexes, but not too severe.

I like the tires, I feel it was a good buy.

Matt16

I meant the guy who posted above you, sorry for the confusion, I couldn't really tell what he was saying, but it sounded like he was mad lol. He might have been talking about his idler arm being mad at the tires though, but my Clingon is a little rusty.

After looking closely at the steering through its range of motion last night, I think its the lift that kills idler arms as well. Lift causes the tie rod to sit at more of an angle to the ground. Basically, the more vertical the impulse from the wheels is (through a angles tire rod), the more harshly its going to push upwards on the idler. At least thats what it looks like. Now, it seems that to fit 33x12.5s you need a lift, and a lot people crank the T bars to do this, which is perhaps a factor contributing to the notion that the bigger tires "cause" idler arm failure.


I'm liking mine still, we have our moments in tight parking garages, but on the whole, its pretty unobtrusive. There is no noise unless I'm coasting around tight corners with the clutch in. I don' think I emphasized the driving style enough. The biggest change to driving style is never to engine brake around tight corners. This causes the locker to jerk, sometimes violently. The trick seems to be to put the tranny into a gear you would normally consider too high, and give it some throttle. This causes the engine to push through the turn, but with very little power so your tires won't screech.

drew303

Bigger tires don't change the forces applied on the idler arm.

Now if you wanted to argue that bigger tires effect the drive train, then well you'd actually have something to talk about.

stormin94

I've got some pics posted up in the YT gallery, since my photobucket won't work with Explorer, on account of Firefox being down for me.

I filled the gas tank today, and averaged 14.5, but 80 of the 175 miles were going against a 40 MPH headwind, so I would guess the next tank will be closer to 16, since I also did some light wheeling for about an hour to get a feel for the tires.

Jay351

I feel the added lift (bj spacers) and the heavy tires add stress on the Idler arm. Like mentioned, I will cook a set of bushings every single wheeling trip, and this is with a *cough downey cough* brace!

With smaller 31x11.50" street tires and stock suspension, I never had a problem..

Saying that the heavy tires don't add stress to the idler arm is a little silly. Your whole steering system must work harder to steer those big meats..

stormin94

I did the 4Crawler 1" body lift, rather than the BJ spacers. I've always had my t bars cranked a little bit (no more than 1 inch). But I definitely see what you mean about the larger tires being tougher on the steering components. I've been taking it easy though. I still get some rubbing when it flexes, or it's cranked hard over, but nothing too severe tho.

Also, if any one is on the fence about doing a small body lift, I would highly recommend the 4 Crawler 1" body lift if you need a little more clearance for your tires, or want to make oil changes and other maintenence easier. It was a very simple and straight forward installation, and only took about 3-4 hours. A few issues I had with the kit was the difficulty installing the front bumper brackets, adjusting the steering shaft, and the gear shifters binding up a little in 2nd, and 4th gears. To eliminate the bumper brackets issue, I just drilled the stock ones so they compensate for about 1/2-3/4 of an inch, so any gap left behind by the body lift in the front is minimal, and I mean very minimal, even without using the bumper brackets. The steering shaft did not want to slide out, but after extensive lubrication, it finally did, and now performs great. As for the shifters, I still haven't resolved this problem. They still bind, even after modifying the metal ring that holds the rubber boot in place. Modifying the ring made a difference, and now it doesn't pop out of gear in 2nd or 4th, but that isn't enough. I am going to try everything shy of cutting the rubber boot to fix this. Although it's probably not a serious problem, it is pretty annoying trying to shift into 2nd or 4th gear. If anyone has any info about this, it is much appreciated.

drew303

First off.. you just said you added BJ spacers... then tires. BJ spacers change the steering geometry. Tires do not. Is it really that hard to comprehend? And I'm leaning towards your opinion of "cooking bushings" to be different than mosts.

Could you possibly elaborate on your idea of "cooking bushings" possibly with some pictures... after every wheeling trip.

It might just benefit the rest of us idiots.

edit* ... ya know to save me a post count
Since when does more ... meat ... also commonly known as weight on the front hubs/suspension/... oh ya balljoints.... oh wait... the steering joints dont carry any weight. They only work laterally. Oh hmm.... Thats funny, I guess bigger tires and their excessive meat don't really put much weight on the lateral working balljoints. Now.. oh wait.. if you wanted to argue that the larger tires create more friction at their contact point to the ground might inherently cause more drag on the 'lateral' movement stress that the steering components endure we might have a discussion. ... since maybe a larger tire is wider. which obviously has a wider footprint which ofcourse allows for more friction.. aka harder to turn the tire plus the addition of the meager amount of weight the larger tire adds to thus physics.... wow.. somehow this all makes the bushings in the idler arm.. which carry no additional stress UNLESS you add bj spacers which .. haha get this.. change the angle of the tierods, wow... so yea... the idler arm takes a bigger .. upforce beating when the suspension flexes if you add balljoint spacers.... but... I'm sorry the weight of the tire has nothing to do with it...

drew303

oh gosh, ok post count +1 for me... I dont feel like editing my post AGAIN. Why not jump on the post count band wagon aye, apparently it makes you smarter if you have posted more. So I've heard.

After adding balljoint spacers to my rig, 3 years ago. I've witnessed that "idler arm" endures more vertical forces .. over stock .. applied to. Thus making it bend to a new .. I like to call it... home. Or in other words a new angle. It literally bends to where it wants to be. So after 3 idler arms (post BJ) .. haha that sounds silly!

I've finally just let it live in its new home... er.. angle. Bushings? Wait.. nope. Bushings are fine. Since last time I checked the idler just turns. If the Idle Arm... is happy in its pivot... So are the bushings. =) But what do I know? Maybe we should ask the idler arm what it thinks?

Matt16

Did you ever take high school physics? For now, lets assume you're talking about larger tire diameters, not width. Larger diameter tire= larger lever arm. In simple terms, this means that when you hit a rut, or the tire is pushed one way or another, the tire's input on the idler arm is more forceful. This is why a stiffer steering stabilizer is needed sometimes when increasing tire size.

Now perhaps if we looked at the rate of wear relative to other factors, you may have something. Lift, as you said bends idlers arms as the tie rods are at more of a vertical angle, thus the force is in an upward direction instead of the mostly horizontal plane on which the idlers arms were designed for. Wider tires has issues too. They provide more resistance to turning which wears steering parts.


There really isn't anything to argue about. Its pretty hard to argue with the laws of physics, unless you're Sarah Palin.

Jay351

Well actually. I had my 33x12.50" BFG Mud terrains first. I got them a few months before I put the BJ spacers in..
I noticed quicker wear, the steering also got worse. So I replaced it with a 30 dollar aftermarket. I saved my worn OEM arm so I could rebuild it later.
That idler arm was done by the time I put my bj spacers on. It lasted for some light wheeling and alot of hwy miles.

I did my bj spacers next... shortly after installing my rebuilt idler and the downey brace. The next time I went wheeling (mild rock crawling) I noticed the wheel was shaking alot on the road... the steering was just sloppy... I pulled the bushings out - and.. it wasnt broken, cracked. Just worn down a substantial amount.... Popped new ones in and the truck drove smooth as ever.

I see Matt stepped in with some good info. I guess you're just a genious. Since big fat heavy mud tires don't add ANY stress to the stock suspension... designed around a 31x10.50" street tire......

Skinsfan6

I have 33x12.50s on my stock ifs with the torsion bars cranked. They have been on for about a year. No idler arm problems. And I romp on it pretty hard. It's mostly mud and rough trails around here, no rocks. Any given day you'll find me sliding around tight corners in the woods. The turbo and locked rear make for some fun in first, second, and third if you know how to use them .

And this summer I took my 4runner to the beach...my first outing since I swapped in the turbo engine, and I got 19mpg on the way down there. I did include in my calculations the tire size difference. Most of the driving I did was between 45-70mph. I have stock 4.10s. They are perfect for interstate driving if you ask me. Going about 60-65 Im turning 2500, and all I had to do is stomp on the gas for the turbo to spool up and pass somebody. Shifting down to 4th is like cheating.

I get 13mpg driving around town back and forth to school. A consistent 13, and that's shifting at 4,000 most of the time. I'm satisfied. It won't get any worse than that, and that's better than my other truck.

Hophead

I have been running 33x12.5's for over a year now with no steering issues. My set-up is BJ spacers, 1" BL and mild T-bar crank. I don't beat on it, but I don't baby it neither . I have a back-up complete steering assembly in the truck - tie-rod to tie-rod with complete idler assembly just in case. Maybe I am just lucky? It seems that everyones mileage is different. Maybe based on OME vs. aftermarket parts....

Matt16

IFS was introduced in 1986 and designed to cope with 223/75r15 tires. 31" tires where introduced in 1992 I think. Coincidentally, the size of the idler arm shaft increased by a bit that year as well. Why, I don't know, but my hunch is it has something to do with tires size, but I'll let you guys make your own guesses as to why Toyota upped the size of the idler arm at about the same time the bigger tires were introduced as a factory (not dealer) option.

Trustyrusty

Yeah I'm not gonna lie, There was no noticable change in how my truck handles or drives when I jumped from 235/75/15's that were on it to 33x12.5" BFG MUDS... No steering problems, nothing. BJ Spacers are the weak link in the whole IFS system, thats why I did a body lift. I'm gonna crank my T-bars 1" and get 1" longer shackles in the rear for a full 4" of lift though. Ever wonder why BJ spacers were the rage in the 80's and died out? They suck.

Matt16

Jumping up tire sizes won't affect your handling immediately. It will over time though. Actually BJ spacers aren't a weak link. They are an indestructible block of metal. I don't even think that they contribute to steering issues by changing the parallel-ness of the A arms. HOWEVER, when used to lift the truck, issues arise. The problems arise from the lift, not the BJ spacers as far as I can tell.

BJ spacers and the '80s. Hmm, I know BJ spacers were used on RWD muscle cars and I also know the mid '80s was about the time of a fuel crisis I think which lead to the popularization of the FWD car which had enough problems with torque steer (with powerful engines) that the front was left alone. While I wasn't exactly doing much driving in the '80s, I'm going to guess that the correlation lies somewhere in there, more than in the assumption that "BJ spacers suck."