RCI aluminum skid plate vibrations

Hi all,

Anyone else have a vibration/ rattle on their skid plates where the engine and transmission plates overlap? I have the aluminum RCI skid plates and have been trying to track down this noise.

When I tap/ bang on the joint where those two connect, the rattle against each other in the middle of the connection. Bolts are tight, but the material seems to flex just enough to rattle. Thinking about putting some weather stripping or rubber between them to stop the rattling. Or maybe drill a hole and add a bolt in the middle of the panels to tie them together better.

Anyone else deal with this?

 

Mine don't rattle and I just came off 50 miles of cobblestone. Did you put the rubber spacers in?

 

If you’ve done a trail run recently, try pressure washing the undercarriage. Could be dirt/debris wedged between the plates? Happened to me…

Might be worth taking the entire thing off and reinstalling to get better fitment?

 

I didn't get any rubber spacers with mine.

Thought it might be something like that but it's all clean/ clear under there.

If I tap the connection between those two plates, it appears it's coming from the slight gap in the center of the two plates. I'll be taking them off to see if there's something I'm missing, though.

 

Don't know if this will work with Flickr (where I back up my photos). But here is link to a video of the issue.

https://www.flickr.com/gp/156579288@N08/YpnF07T310

 

Oh god, it's hard to even navigate that.

Just upload it on youtube.

If you have plates vibrating against each other, just put some adhesive foam tape; sticky on one side and soft foam on the other.

 

It could be the cross member below the front Differential that is touching the skid plate. They have a bit of of a give sometimes. Or the spacers as other suggest. Or wait....I had the flat section of the exhaust touching the middle skid plate but I got the spacer and problem solved. Good luck.

 

Ya. I think that's the best solution.

 

Hitting the exhaust is the usual issue, but they may have redesigned it because I have plenty of clearance.

 

You might be on to something. Took another look the other day. There is a subframe (?) right above the connection of the front and middle skid plates. Doesn't appear to be any clearance so the plate could be vibrating on that.

I wrote RCI to get their opinion but haven't heard back. Maybe this weekend, I'll pull them off and add some washers and see what happens.

Uploaded a couple videos:

https://www.youtube.com/watch?v=H2vsgYCj7Wo

https://www.youtube.com/watch?v=_x5lHsGUvuo

 

Mine do this since I add the cat guards on my taco. It’s just that way when I start the truck up. Not while driving

 

Finally got around to pulling the front skid plate. Middle plate was resting on the subframe. Maybe it's supposed to be that way? Couple taps and could duplicate the vibration. Went out and bought a couple different nylon washers/ spacers. Picked one that spaced it off the subframe and tightened everything back up (leaving the front skid off for now). I'll see how it goes.

Although I've heard them vibrating, after banging around on the skid plates, the noise I'm chasing doesn't really sound like it's related to the plates. I'll leave the front skid off and see how it goes.

First pic you can see the plate resting on the subframe. Second pic shows washer.

 

I hope it works. I'm staying tuned for a longer-term report.

 

Front skid plate back on. I still heard the noise with it off. The noise I'm trying to find sounds more like it's in the engine/ transmission. Kind of a "whirring", "zzziiinng" sound. That's the best I can describe it. Almost metallic. Not heat shield metallic, though. Only happens just off idle in gear (Drive or Reverse). Can be duplicated sitting in the garage with my foot on the brake, car in D or R and giving it the slightest bit of gas. Can also be heard in parking garages or coming up the hill to my house if I drive slow enough.

Probably one of those normal 4Runner drivetrain sounds. I don't believe I heard it for the first 8,000 miles or so, though. Everything did get louder with the skid plates on (assume they reflect sounds up into the cabin). It definitely seemed more quiet with the front skid plate off. I'll have them check out the sound at the 10,000 mile service in a few weeks.

While the sound was not related to the plate resting against the subframe, I left the white washers on only because I had already glued them to the black RCI spacers. In the end, probably normal for that plate to rest against the subframe.

Rattling when hitting the plates was caused by both sets of plates overlapping. Adding a piece of soft velcro in the middle where the plates overlapped and it all but eliminated it. I also added soft velcro underneath the oil filter access cover. Apparently my kryponite is metal rattling against metal.

As I had read posts about stripping the skid plate bolt-hole threads, I was very cautious about not stripping them the first time and it was tough to get everything aligned with the holes being slightly off.

While the front skid plate was off, I filed out the front and middle (tube) holes. 100% easier install this time. Should have done the rearmost holes also, but they were no where near as bad so it only took a little more effort to get those bolts in. The holes were not off a lot, but they didn't have to be to make the install more difficult than it should have been the first time.

Also, I didn't like that the front "filler plate" plastic cover was not installed. Added it back on. Front bolts are in original spots. Drilled a hole in the skid plate for one self-tapping screw for the rear center hole. If not having the outer two screws becomes an issue (can't imagine it will) I'll figure out a way to attach them to the skid plate.

Pics:

Incorrect alignment of holes. Blue tape used to make template from subframe.




Picture showing pressure on the bolt caused by mis-drilled holes.





Egged out hole after filing (did both middle holes like this).





Front Filler Plate installed

 

The plot thickens here.
I wonder if you damaged a little the exhaust piece that looks flat right in the middle of the truck before it goes to the top and to the right. That flat section could sometimes touch the skid plates if you don't have the spacers in there. I would trace the entire exhaust pieces and see if they are loose somewhere.

 

Question - what torque are you using on the skid plates? I ask because I had a recent noise when at low speeds and turning and it turned out to be my RCI skids. I didn't have hole alignment issues like you did, I'm just an idiot. I set my torque wrench to 22.5 newton meters when installing (22.5 ft/lbs was OEM spec from what I remember, 30 newton meters). RCI reccomends 30 ft/lbs (not sure if that is a newton meters to ft/lbs mistake and should be OEM) but I tightened them all down to the 30 ft/lbs recommended by RCI and my mystery noise is now gone.

I have the cat guards as well and didn't torque them - just used the gudentite method

 

Very common area to have interference with a skid plate, but, in my case there is an inch or two of clearance. Same with the transmission's OEM skid plate which is still installed.

 

I torqued them to 22ft lbs. The reason for this is that I used anti-seize on the bolts. According to the all-knowing OZ (google), one should reduce the spec'd torque by 25-30% when using anti-seize. The reason being it's essentially lube, so it's easy to over torque a bolt. I don't remember if I torqued the cat guard bolts or just gudentited them as you did.

I do (did?) have a "Spronggggg" type of sound when going over parking lot drainage channels at an angle at moderate speed. Definitely a skid plate noise. I could easily duplicate it before going into the Costco gas station so I'll try again when I get gas next. If I get that same noise, I can tighten them up to 30ft lbs just to see if it goes away.

 

Sounds like you did it correctly.

I feel your pain. Having a weird noise drives me nucking futs