To all you with rear plate bumpers and a tire swing out

[tS_kStin]

So here is the deal, I just finished my mod of the Bandit runner rear bumper by putting a rear tire swingout w/ two jerry cans. I love it but ever since I put it on I have a very unpleasant rear end wag. I noticed it first when doing 50+ and a lot on the highway doing 70-80. I recently did the Toytec BOSS coilovers with the superflex coils in the rear. I didn't notice this wobble in the rear even when I had my spare in the rear hatch and 80 pounds or so of extra weight to get the coils to settle with weight before the swingout was done.

The Wobble is usually set off by either a slight side wind or a bump in the road that effects only one side then disrupting the balance of the truck. Sometimes it goes away quickly othertimes it just keeps wagging back and forth like a dog wagging its tail.

What I am running in the rear is superflex coils with toytec boss shocks, custom extended swaybar links, and a custom panhard drop, stock everything else. All on very worn down Cooper Discoverer AT3s 265/75r16 that will be changed out soon. PSI tested anywhere from 25-40 and still happens (not as bad at 40)

So what I am wondering is if this wobble is just because of the new weight distribution in the rear and I just have to deal with it? Or is it some wore out 214xxx mile bushings in the arms going from the frame to the axle that just need to be replaced? Or something I am just not picking up on?

Also a pic of the swingout because why not? it is double hinged so that I have two swingouts for a table on each side, one for my and one for the wife. And I like the idea of less weight on each hinge so they work better for longer. Hinges by 4xinnovations.

 

[Scramble]

I dont have a rear bumper with swing out but I had an old set of tires on my truck & at 70,000 miles the side walls were shot & the truck had a lot of sway side to side & it was corrected with new tires. They'll wear out quicker too if you air down a lot.

 

[tS_kStin]

I dont have a rear bumper with swing out but I had an old set of tires on my truck & at 70,000 miles the side walls were shot & the truck had a lot of sway side to side & it was corrected with new tires. They'll wear out quicker too if you air down a lot.

Yeah I don't think my sidewalls are shot because the tires are not all that old, just got really bad and quick wear on them from bad alignments. I don't actually air down all that much, it just so happened I was when I was headed home from a wheeling trip. But I noticed it a little on the way out there so I don't think it was caused by the trail. I am hoping that the new set of tires help.

 

[Kotrin]

So I don't have a swing away yet, it will come hopefully in the next year(or less if I can get my dad to help me..). So anyways, I have a complete steel bumper already on the rear versus stock and I haven't noticed anything. I had similar wait during my overlanding trip and had no issues what so ever. I have almost the same exact setup as you for suspension minus the stock track and panbar.

Here is a picture


Here is what I'm going to do -

 

[JayRolla]

I would feel this issue when I loaded down. I just had LC coils and tokico shocks with the front sway bar removed.

IMO the panhard drop is not really needed. I installed an adjustable rear panhard bar. The rear end was about 1" off from the front tires. Once aligned and added front sway bar I have no sway or wobble in the rear.

Like you say make sure you upper and lower control arm bushings are good also.

 

[Scramble]

Like you say make sure you upper and lower control arm bushings are good also.

I would check this next if your sidewalls are good.

 

[MillerPKA]

This is something I'm chasing now and your description is pretty on point to what I've seen at times.

I had upgraded rear upper and lower control arms, Superflex coils and Toytec Boss remote reservoir shocks. I swapped out to 861s this past weekend and it's definitely helped. But the feeling is still there. Sometimes it will bounce itself into a motion that rocks the tire up and down pretty good.

Finally I had someone shaking the tire assembly while I was looking under the truck, and I noticed the body mount bushings are allowing a ton of movement between the body and frame. Based on the feeling I get in the driver seat when it starts behaving like that, I think this is potentially the culprit. Sonoran Steel has some poly bushings that I am going to pick up this week. Check out this link

Rear 4Runner Polyurethane Body Mounts (Pair) - $75.00 : Sonoran Steel, Sonoran Steel Custom Metal Fabrication L.L.C. Custom Toyota Truck Parts

Another thing to note, I was talking with CBI about this and he mentioned one of the issues is the distance between the end of the frame and the rear bumper positioning.

I'll keep you posted after I do the body mounts.

 

[Sean K.]

This is something I'm chasing now and your description is pretty on point to what I've seen at times.

I had upgraded rear upper and lower control arms, Superflex coils and Toytec Boss remote reservoir shocks. I swapped out to 861s this past weekend and it's definitely helped. But the feeling is still there. Sometimes it will bounce itself into a motion that rocks the tire up and down pretty good.

Finally I had someone shaking the tire assembly while I was looking under the truck, and I noticed the body mount bushings are allowing a ton of movement between the body and frame. Based on the feeling I get in the driver seat when it starts behaving like that, I think this is potentially the culprit. Sonoran Steel has some poly bushings that I am going to pick up this week. Check out this link

Rear 4Runner Polyurethane Body Mounts (Pair) - $75.00 : Sonoran Steel, Sonoran Steel Custom Metal Fabrication L.L.C. Custom Toyota Truck Parts

Another thing to note, I was talking with CBI about this and he mentioned one of the issues is the distance between the end of the frame and the rear bumper positioning.

I'll keep you posted after I do the body mounts.

I think this is the correct answer. However....and nothing against the Sonoran Steel kit, but why wouldn't you just get a full kit from Energy Suspension? Energy Suspension 8.4110 - Body Mount Bushings. Energy Suspension

The 8.4110 is the kit for a 3rd Gen Runner.....around $148 shipped from Jegs: http://www.jegs.com/i/Energy-Suspension/355/8-4110G/10002/-1 . My 4Runner is 18 years old this December....the rubber body mounts around the truck look okay....but it probably wouldn't be a bad thing to switch them out, though I realize poly is going to result in more felt vibration.

***EDIT***JFYI....always try and get the black color bushings from Energy. The part number for this application (at least a '99 model) is 8.4110G. The G signifies "graphite" impregnated bushings....and my understanding is that Energy only does this to black bushings, so while red looks cool....it doesn't have the graphite. ***

 

[MillerPKA]

I think this is the correct answer. However....and nothing against the Sonoran Steel kit, but why wouldn't you just get a full kit from Energy Suspension? Energy Suspension 8.4110 - Body Mount Bushings. Energy Suspension

The 8.4110 is the kit for a 3rd Gen Runner.....around $156. My 4Runner is 18 years old this December....the rubber body mounts around the truck look okay....but it probably wouldn't be a bad thing to switch them out, though I realize poly is going to result in more felt vibration.

***EDIT***JFYI....always try and get the black color bushings from Energy. The part number for this application (at least a '99 model) is 8.4110G. The G signifies "graphite" impregnated bushings....and my understanding is that Energy only does this to black bushings, so while red looks cool....it doesn't have the graphite. ***

I'd like to see the energy bushings for the rears compared to the SS ones. I agree but it sounds like he made them with this problem specifically in mind, so if they are beefier I would probably go with his.

As for your body mounts, looks can be deceiving. Rock your body and have someone checking the movement, especially in the rear if you're running plate and a spare back there.

 

[Sean K.]

I'd like to see the energy bushings for the rears compared to the SS ones. I agree but it sounds like he made them with this problem specifically in mind, so if they are beefier I would probably go with his.

As for your body mounts, looks can be deceiving. Rock your body and have someone checking the movement, especially in the rear if you're running plate and a spare back there.

The pics look VERY similar.

I've done the rock test and the 2 rear-most mounts allow tons of movement. The rest of the mounts seem fine...but I figure if I'm going to spend the money, might as well replace all of them....though I may wait until I've welded everything to the frame since I've had to wrap wet towels around the front-most two while welding different bumper attachments to keep them from potentially melting.

 

[Chim]

I had/have the 4xinnovations bumper with tire carrier, gas can, jack, and I also run the sonoran rear body mounts. I have the superflex as well. When I hit any bump and most any speed the rear swing out would vibrate and wobble just enough to feel it to make me feel like something is loose out back. I have no idea how to remedy this but knowing what it is is reassuring. :/

 

[Coward]

I don't have any of the mods you have. But I have experienced the same issue in other vehicles due to being overloaded, worn tires, or especially low tire pressure. If it was better at 40psi it sounds like that might be at least part of the issue? What is the max psi for those tires? Maybe try max psi and see if that corrects the issue. As the others said, if you run your tires as low as 25, that wears the sidewalls over time. And weaker sidewalls would feel just like a low tire(s). Your certainly not over loaded weight wise. Or its some of the bushings. Or it's something else all together. Good luck.

 

[Bandit Runner]

Sorry, I'm no help with the issue your having.

However, I just wanted to say that your bumpers and swing-outs turned out real nice! Let's see a pic of the swing-outs open and the tables set up.

 

[Sean K.]

I had/have the 4xinnovations bumper with tire carrier, gas can, jack, and I also run the sonoran rear body mounts. I have the superflex as well. When I hit any bump and most any speed the rear swing out would vibrate and wobble just enough to feel it to make me feel like something is loose out back. I have no idea how to remedy this but knowing what it is is reassuring. :/

Hmmm....well, guess that rules out the body mounts.

 

[Chim]

I still highly recommend the sonoran rear body mounts! My bumper flexed up till it hit the body without them.

 

[gamefreakgc]

This was only mentioned once so far... has the anti-sway bar been removed or disconnected? Are the bushings on the sway bar in good shape? This is what the anti-sway bar is for, after all, eliminating vehicle sway.

If not I highly recommend the Energy Suspension ones. Put them on my 4Runner and handles much, much better. They are stiffer than stock so allow even less movement.

 

[Sean K.]

I still highly recommend the sonoran rear body mounts! My bumper flexed up till it hit the body without them.

Agreed. Still a good idea to keep the bumper from kissing sheetmetal. I was just saying it likely won't cure the OP's problem.

 

[tS_kStin]

I would feel this issue when I loaded down. I just had LC coils and tokico shocks with the front sway bar removed.

IMO the panhard drop is not really needed. I installed an adjustable rear panhard bar. The rear end was about 1" off from the front tires. Once aligned and added front sway bar I have no sway or wobble in the rear.

Like you say make sure you upper and lower control arm bushings are good also.

For me the panhard drop was the better cheaper option. I didn't want to pay for an adjustable one and making a drop to center the axle back up only cost like $5... The thing was when I drove with the stock bar not dropped the rear end would kick to one side over every bump because of the bar length, angle and axle being offset. So the drop took care of all that but now I have this different wobble...

Going to check the bushings for sure.

 

[tS_kStin]

This is something I'm chasing now and your description is pretty on point to what I've seen at times.

I had upgraded rear upper and lower control arms, Superflex coils and Toytec Boss remote reservoir shocks. I swapped out to 861s this past weekend and it's definitely helped. But the feeling is still there. Sometimes it will bounce itself into a motion that rocks the tire up and down pretty good.

Finally I had someone shaking the tire assembly while I was looking under the truck, and I noticed the body mount bushings are allowing a ton of movement between the body and frame. Based on the feeling I get in the driver seat when it starts behaving like that, I think this is potentially the culprit. Sonoran Steel has some poly bushings that I am going to pick up this week. Check out this link

Rear 4Runner Polyurethane Body Mounts (Pair) - $75.00 : Sonoran Steel, Sonoran Steel Custom Metal Fabrication L.L.C. Custom Toyota Truck Parts

Another thing to note, I was talking with CBI about this and he mentioned one of the issues is the distance between the end of the frame and the rear bumper positioning.

I'll keep you posted after I do the body mounts.

Yeah let me know about those body mounts, im going to have to check mine to see if they are doing anything like that. I have not been under my truck yet with someone moving it see anything yet.

 

[tS_kStin]

I don't have any of the mods you have. But I have experienced the same issue in other vehicles due to being overloaded, worn tires, or especially low tire pressure. If it was better at 40psi it sounds like that might be at least part of the issue? What is the max psi for those tires? Maybe try max psi and see if that corrects the issue. As the others said, if you run your tires as low as 25, that wears the sidewalls over time. And weaker sidewalls would feel just like a low tire(s). Your certainly not over loaded weight wise. Or its some of the bushings. Or it's something else all together. Good luck.

The odd thing is this was the only the second time I have ever aired these tires down. However I am not putting tires out of the equation because the tire presser has been all over the place in them because I am pretty sure every single tire has a patch in it now due to slow leaks. So very well could be some wore out side walls from over the years of leaking out then filling up.