When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I've been destroying idler arms quite a bit lately and I'm not sure why. I'm hoping somebody might have some ideas. The first time I replaced the arm was about seven months ago. It had severely worn bushings. I replaced it with a cheap O'reilly one. It lasted about three months. Ate the bushings. I warrantied it. Ate the bushings again in about two months. I then bought a Mevotech Supreme. I've had excellent luck with Mevotech and is usually my preferred aftermarket for steering and suspension. I put them on customers vehicles all the time and haven't had one come back yet. This one however ate the ball joint end in about a month. I had an out of town wheeling trip coming up and needed to get it fixed before driving it through the mountains. I wound up swapping the Mevotech bushings into the O'reilly arm. It drove great. I drove it 80 miles or so to the event. Drove the river for about 20 miles in 20 miles out. About 40 miles back on the highway it started getting its shake back. By the time I got back in town it was back to the good ol' wandering and shaking Toyota I grew to know and love. So overall about 200 miles killed the bushings again.
Now, I understand that they are relatively unreliable arms, but damn! I wouldn't expect anything like this. I get it that trucks with big tires and lots of lift is more likely to kill em but all I got is 33x10.5. The suspension is completely stock otherwise. Is there anyway there is something else wrong that might be putting too much stress on the arm. The ball joints, tie rods, and pitman arm were all replaced the same time I installed the Mevotech arm. They are all Mevotech Supreme. The control arm bushings are worn but don't have any noticeable play. The spindle bushings are almost non existent. I have new control arm bushings already but I'm waiting to get the spindle bushings to install them. May as will kill two birds with one stone. The brakes and wheel bearings are about a year old and have been repacked about six times since then (I really need to get those spindle bushings replaced).
What do you guys think? Am I missing something? Are they really this unreliable? Should I try to find a set of bronze bushings and will that fix my problem all together. Maybe a brace will help. I expect those will be best to prevent bending but not so much on the lower bushing wear. I have yet to bend an idler. I might just buy a set of bronze bushings and try it.
Last edited by Kolton5543; 06-20-2018 at 10:36 PM.
I know you said your suspension is stock but in case you left out a detail or in case someone else finds this thread later when chasing a similar problem, I'm going to warn against ball joint spacers. I bent a one idler arm while I ran ball joint spacers. I also ate a pair of front tires. I also killed multiple lower ball joints. Ball joint spacers are a bad idea. It is 100% possible to get a proper static alignment with BJ spacers. The problem is that it is also 100% impossible to get a proper dynamic alignment. By the nature of how they work ball joint spacers will change the path that the tire travels through as the suspension moves up and down. So during those situations, such as leaning during a turn, the tire isn't aligned properly and you get excessive wear. The other problem is the stress they put on the steering. In stock configuration the tie rods are fairly flat. They are close to parallel with the drag link/center link. This means that any force put on the tie rods is mostly horizontal and very slightly vertical. The horizontal force is what is used to steer left and right. The vertical forces are just resisted by the idler arm and steering box. This is no problem in the stock setup because the forces are small and within strength limits. BJ spacers move the knuckles down. This means the tie rods are at a greater angle. They are no longer very close to parallel with the center link. They now have a fairly significant angle. This means that they exert a horizontal force on the center link just like before, but a much larger vertical force. The vertical force will put greater stress on all parts of the idler arm, and possibly bend it. I've bent one and I wasn't even hard in the rocks. I was on 31 inch tires wheeling in the woods. My recommendation is don't run ball joint spacers. Keep the IFS stock or SAS it.
The grease I have been using is a basic moly grease. I use it on everything and it seems to work good. As for any other suspension parts wearing out, not really. I had one bad ball joint and decided to replace all of them at the same time. Same with the steering. The idler arm was bad and the rest of the components showed no play but were old so I just did them all. So far they all are holding up well.
As for the ball joint spacers I am well aware of how they effect the suspension geometry. I don't run em because of that. I mean I literally have stock suspension. The rear has some moog stock replacement springs to take care of the sag and that is it. The torsion bars haven't even been touched.
Last edited by Kolton5543; 06-21-2018 at 07:10 PM.
Yes my son and I replaced his ider arm last month when we realized that the clunk was caused by the fact that the lower bushing had completely gone. This was after we had done a couple of off pavement trips, December 2017 was when we aquired the vehicle so the history is moot for its 28 years. Alas we put in a $40 dollar Oreilly unit which is plumbed for a zerk but did not have one in it. I think brass bearing material will be a whole lot better than Delrin if that is the plastic they typically use to refurbish these. Back in the day (Early 80's) we used to wreck this part of the steering on a SCORE 7S truck (Falkosky Racing) and realized that the idler arm needed reinforcing and the steering arms bolts on the 1 ton 2 wheel drive spindles needed to be enlarged some then you were pushing 12" of wheel travel out of the stock geometry. JD Fabrication has a sweet upgrade that I think is the right stuff because the ball joints on the OEM pitman and idler arms allows the drag link to swivel. I can see that this can alter the toe set a little with so many degrees of freedom supplied to the component when the joints are a bit tired. JD Fab puts bushings on the pit/idler arms and that disallows the drag link to swiwel the way it can on the OEM balljoints. Then the tie rods and there respective ball joinds do all of the swivelling and the drag link only can translate from left to right as steering input is dictated. It makes it a bit more like a rack that the tie rods are attached too. The kit is a bit steep in price, ($1,420) but take a look and see what you think for yourself. https://jdfabrication.com/products/t...4-steering-kit
One more point to be touched on is that the swivel axis for the ball joints at the ends of our respective A-arms are a very long way fron the center of the contact patch on the OEM 31x10.50R15 tires. That distance is called a scrub radius and on really excellent handling sports cars the suspension design will often not have any scrup radius or it will be a fractional distance from the king pin axis. All of which is to say that this scrub radius that we enjoy on our Toyotas of this era will cause a good bit of tugging on the tie rod when drive torque or brake torgue is applied to the wheel and tire.
Cheers, Andrew
alindsay1992,
Can you elaborate more on the issue with using a ball joint spacer to space apart the A-arms with a "spacer kit"? It seems like a keen way to open up the wheel travel and not really mess up the alighnement if the torsion bar is relaxed some to offset the lift from the spacer. As a new owner of a 1990 and 1991 pair of 4Runners I was seriously looking at installing one of these kits.
Cheers, Andrew
Last edited by Andrew Parker; 06-21-2018 at 01:11 PM.
Andrew, that JD fab kit looks damn tough but its price tag isn't gunna let it happen. It is cool though. For the ball joint spacers, what he is saying is that a truck can be put into alignment. But it will only stay in its alignment at ride height. When the suspension travels it the controls arms swing in an arc. the length, position, and orientation of the arms define the location of the knuckle. Adding the ball joint spacer is going to change the orientation of the lower arm, thus adding lift. This however pulls the lower arm inward along its arc. To counteract it, the lower arm will just be moved further out during alignment. It will be aligned at ride height. But when the suspension cycles up and the lower arm is now almost flat, the end of the arm is going to be further outward than before. This gives more negative camber under compression and it will cause the tire to toe in a little. Also if it moves far enough, the upper control arm can move past horizontal and pull inward some more. At this point it will counteract some of the change in toe but will give even more negative camber. In the end. It's harder on components and can make it drive a bit weird on the road.
Kolton is correct. Messes up the suspension geometry. Not saying you're going to go through tires in two months, or that you're not going to be able to stay in your lane, but it's not a perfect solution. It will dramatically increase wear and tear on a number of front end components.
Your right about the Total Chaos arm but its price tag isn't justifiable. Plus it still doesn't resolve the issue thats causing bad arms. Maybe I just have bad luck but maybe there is something else thats wrong.
Your right about the Total Chaos arm but its price tag isn't justifiable. Plus it still doesn't resolve the issue thats causing bad arms. Maybe I just have bad luck but maybe there is something else thats wrong.
You have to pay to play, so what price tag is justifiable to you?
The fact that you said you wheel your truck, and only you know what kind of wheeling you do and what abuse it sees, should be justification to spend money and upgrade whats needed. The idlers on these trucks are a known weak point, that's why there are upgrades available, with the 3 options that have been posted here.
If there is an underlying issue with your truck, either you'll have to get under it and find it or pay someone to.
Ok so I'm still having issues with my idler. I'll give a rundown on what's happened with the last one. I just rebuilt the entire front end. Ball joints, tie rod ends, adjuster sleeves, and pitman arm are all Mevotech supreme. Control arm bushings are all poly from Energy suspension. New torsion bar bolts from LCE. The idler arm is a Duralast arm with 4crawlers bronze bushings.
immediately upon completing the work I took in for alignment. It drove fantastic. I took it to Tucson that weekend to run Chiva Falls. It's not a difficult trail at all and the majority of it is done in 2wd. It was a 200 mile drive there. Maybe 100 miles I drove in Tucson and about 100 miles on the way back the truck started shaking again. I found the idler had play in the bushings and play in the centerlink end. I've since driven about another 300 miles since then. Total of maybe 700 miles since the rebuild.
I ordered up the Proforged idler and pitman arms this time and another set of bushings.
I disassembled the old arm to inspect the damage. Here's a picture of the bushings.
you can see from the scoring they were actually turning inside the idler body
Here is the idler body.
Again you can see they were turning in there. The bushings diameter hasn't even changed. The body took all the wear. I suspect the water intrusion is probably from some mud I was stuck in a couple weeks ago.
Here you can see how much play there was in the steering link.
if you watch closely, you can see that most of the play is coming from the centerlink rotating.
This is the amount of play afterwards
No centerlink rotation. What I noticed is the idlers have a rotating stud but it doesn't pivot, thus locating the centerlink. The pitman, however, has a ball joint and plays no part in preventing the centerlink from rotating. I'm wondering if this is putting additional stress on the idler. Both the Mevotech, the Proforged, and the one I originally replaced were like this.
Does anybody know of a pitman that has only a rotating stud? I'm willing to give it a shot if it exists.
Is the ball joint in the pittman arm worn? Mine is quite stiff even after being on the truck for god knows how many thousand km.. Otherwise I'd inspect the remainder of the steering linkage for bent or worn/loose parts that may be aggravating the wear in your idler. Is there a lot of excess weight in the front end of your truck and do you tend to turn the wheel frequently while the truck isn't moving? I understand this is a point of failure in these trucks but this seems excessive.
Do you have your torsion bars cranked at all, or any other kind of a lift? The steering linkage is designed such that its presumed normal operating state is with all of the links in horizontal alignment, with the control arms centered between the bump stops. That minimizes the rotational twisting forces on the links and the various joints.
If you have the torsion bars cranked or some other arrangement that causes the control arms to operate in a significantly drooped configuration, it will add extra twisting stresses to the linkage joints and could be causing your early failures.
Generally testing for play with the wheels completely drooped will give you an exaggerated indication of actual play vs. when the control arms are in the center of their range. You really need to test for play with the front end supported at the outer ends of the LCA's, so that the steering linkage is in its normal configuration.
The last pitman arm did have play in the joint. That's why I just replaced it. I'm curious as to why it's a ball joint rather than a rotating stud. It doesn't make sense to why they would be like that.
As for the torsion bars, no they are not cranked. When I replace the torsion bolts I ran em in till the front sat level with the rear. Only thing in the rear is factory replacement springs. I shaved bump stops but that's it. The front isn't much heavier than normal. It does have a 3.4 and a winch that weighs about 70 pounds. So a little heavier but not by much.
I understand that full droop will exaggerate the play. We have a drive on lift with air jacks that we use to to check for play in steering and suspension. It's only on the lift in the pics because I put it up there to change the parts. There currently is no signs of wear in any other components. Or any bent parts. The guy at the alignment place said its one of the easiest ones he's ever set.
What gets me is it only seems to wear out on a long highway drive. I can drive off-road only for weeks and it's seems to be fine. But once I'm on the highway for more than an hour is when it starts shaking and shows signs of wear. Maybe it's coincidence. Maybe there's something else I can't see.
Last edited by Kolton5543; 12-20-2018 at 03:30 PM.
That is pretty puzzling, because I have almost the exact same setup - 33x10.5x15 tires, stock suspension, centered between the bump stops, and my steering components just keep going and going. I think everything is original except for the idler arm which was replaced 80,000 miles ago due to a recall. The truck still goes down the highway pretty much "hands off"; no pull, wandering, or vibration of any kind. Better than my '06.
In looking this thread over Kolton5543, I would get the 4Crawler brass bushings and the proper casting with the largest idler shaft at Ø20mm (.786") which it seem you have done. I would make absolutely sure the bushings are securely fixed in the housing through either a correct press fit or if they are loose I would clean and then J&B weld them into the housing. Then assuming the shaft on this assembly is a good fit inside the bushings with no feel of looseness I would drill and tap the housing for a zerk and grease the blasted thing on a regular basis to keep all that muck out of the lower bushing as the zerk will purge any mud or worn brass particulates as this thing degrades with time. If this fails in short order again then I would be inclined to see about getting a custom housing made with larger diameter needle roller bearings with hardened race ways to bear the rather high static loading our rigs can sometimes seem to be imparting on this idler arm assembly. It seems that this bearing design is not failing from too much rotational speed or PV values but from high bearing loads which in a nutshell means that the shear area of the shaft in the bushing is too small. A longer bushing at the bottom would help some if the housing will allow it? But as 4CRAWLER indicates a bigger diameter shaft and bearing is the better bang for the buck solution.
As for why some rigs kill this idler arm and others do not a well thought out design of experiments might help us get to the root cause but the variety of modifications we can make is endless in counting the variables. As an adage from my first job out of college as a tool design and automation engineer the saying goes like this, "when it doubt make it stout"!..
06-20-2018, 10:32 PM
