Exhaust pipe clearance issue on transfer case skid plate?

[Grug556]

Hey guys ive got the RCI skid plates, full set. Anyhow I have read on the transfer case plate that you can have contact with exhaust pipe near where it S bends behind the transfer case area. This pipe is very close to coming in contact with the skid plate, even when plate is pushed down as far is it will go (which also makes another problem listed below), I read a few people online wrapped the pipe in exhaust pipe wrap. I did the same. Now the pipe lightly touches skid plate due to thickness of heat wrap. What do you think? Plates are aluminum and coated. you see any issues with mild contact of pipe and plate if the pipe is wrapped?

Lastly the transfer case support cross bar, that secures the plate to, even in its farthest down location leaves the end side of the plate with outside gaps of roughly 1/4 inch. To clarify I am talking the end pieces of this transfer case brace. Each side is held into the frame with 1 M8 bolt. Its slotted so you raise and lower the bar. The lowest position offers the maximum amount of clearance for the exhaust pipe over the transfer case skid plate as listed above. Anyhow when its depressed like this, the end side pieces have a 90 degree wrap around the bottom of them which goes out around the bottom on the frame rail by about 1 inch on each side. Its between this piece under the frame rail where there is now roughly a 1/4 inch gap on each side. I was wondering, should I try and fill this gap with some bar stock or similar? Reason being if the crossbar took a hard hit, it would like move upwards on the M8 slots. I thought it I put in spacers underneath it would eliminate any possible upward push of the bar? Any ideas on this? Choice was mild steel flat bar or possibly aluminum flat bar. I was planning on drilling a hole on each side and securing bottom section of crossbar with spacer and then drilling and tapping and securing whole piece to the frame with a M10 or 8.

What do you guys think ? Anybody else have fitment issues with RCI skids? Their designs now in place seem abit weak. Thanks for any help

 

[Humble Leader]

I will share some ideas - not sure how helpful they will be. I can't speak from experience since I do not have RCI skids

I have read about fitment issues with RCI skids, both on 4runners and on tacomas. have you contacted RCI? maybe they will send you some new skids, maybe they will fit better. did you order these directly from RCI or somewhere else - perhaps you have an older version

second, as a rule of thumb I avoid vibration at all costs. without the exhaust wrapping you'd for sure get vibration. you might still get some vibration noise with aluminum skids and wrapping. my issue with the wrapping coming right up to the skid is that dirt, sand and small stones could wedge themselves in there and act like sandpaper on the wrap - eventually making it useless. it really depends on how much you wheel and where you're wheeling. steel spacers with actual space between the exhaust and the skid are probably the best way here. I'm not sure I understand your second paragraph completely

when it comes to spacers though you may have to fabricate your own if you're handy. might be hard to find steel ones that thick. you could use nylon spacers and they likely would be fine but a real hard hit might break them

if you are going to go the spacer route, don't stack a bunch of flat washers and you may need longer bolts. you need to make sure an adequate number of threads are exposed after threading the bolt for an optimal connection (2-3 generally)

 

[Grug556]

I will share some ideas - not sure how helpful they will be. I can't speak from experience since I do not have RCI skids

I have read about fitment issues with RCI skids, both on 4runners and on tacomas. have you contacted RCI? maybe they will send you some new skids, maybe they will fit better. did you order these directly from RCI or somewhere else - perhaps you have an older version

second, as a rule of thumb I avoid vibration at all costs. without the exhaust wrapping you'd for sure get vibration. you might still get some vibration noise with aluminum skids and wrapping. my issue with the wrapping coming right up to the skid is that dirt, sand and small stones could wedge themselves in there and act like sandpaper on the wrap - eventually making it useless. it really depends on how much you wheel and where you're wheeling. steel spacers with actual space between the exhaust and the skid are probably the best way here. I'm not sure I understand your second paragraph completely

when it comes to spacers though you may have to fabricate your own if you're handy. might be hard to find steel ones that thick. you could use nylon spacers and they likely would be fine but a real hard hit might break them

if you are going to go the spacer route, don't stack a bunch of flat washers and you may need longer bolts. you need to make sure an adequate number of threads are exposed after threading the bolt for an optimal connection (2-3 generally)

Thanks, yeah bought direct from RCI. I thought about the spacers, even got a couple but I think flatbar may have a more uniform contact area. YOur comments on debris abrading the wrap was a good point, I hadnt thought of that. Dont want to use any Thermoplastics in case they get brittle during cold here and snap.

 

[Humble Leader]

Thanks, yeah bought direct from RCI. I thought about the spacers, even got a couple but I think flatbar may have a more uniform contact area. YOur comments on debris abrading the wrap was a good point, I hadnt thought of that. Dont want to use any Thermoplastics in case they get brittle during cold here and snap.

yes no plastic. the goal should be to avoid contact by a fair margin (maybe 1/4") because at idle you might not have vibration but say in reverse or downshift you might, so you need to make sure you do a good driving test

a flatbar would work, make sure it's hardened if you can. I know home depot sells steel flats in stainless steel. you could probably stack 2 1/8" flats or make some sort of spacer from that. if they have 1/4" flats even better.

obviously you have to work with what you have. my suggestions on spacers, bolt lengths, etc. are to make the most engineeringly sound (that I can come up with anyway) solution to your problem with the least risk of failure. the last thing you want it to bash on your skids, have them break from their mounts, break your exhaust pipe and break whatever they were supposed to be protecting as well. that would not be a good day

 

[fkheath]

Hey guys ive got the RCI skid plates, full set. Anyhow I have read on the transfer case plate that you can have contact with exhaust pipe near where it S bends behind the transfer case area. This pipe is very close to coming in contact with the skid plate, even when plate is pushed down as far is it will go (which also makes another problem listed below), I read a few people online wrapped the pipe in exhaust pipe wrap. I did the same. Now the pipe lightly touches skid plate due to thickness of heat wrap. What do you think? Plates are aluminum and coated. you see any issues with mild contact of pipe and plate if the pipe is wrapped?

Lastly the transfer case support cross bar, that secures the plate to, even in its farthest down location leaves the end side of the plate with outside gaps of roughly 1/4 inch. To clarify I am talking the end pieces of this transfer case brace. Each side is held into the frame with 1 M8 bolt. Its slotted so you raise and lower the bar. The lowest position offers the maximum amount of clearance for the exhaust pipe over the transfer case skid plate as listed above. Anyhow when its depressed like this, the end side pieces have a 90 degree wrap around the bottom of them which goes out around the bottom on the frame rail by about 1 inch on each side. Its between this piece under the frame rail where there is now roughly a 1/4 inch gap on each side. I was wondering, should I try and fill this gap with some bar stock or similar? Reason being if the crossbar took a hard hit, it would like move upwards on the M8 slots. I thought it I put in spacers underneath it would eliminate any possible upward push of the bar? Any ideas on this? Choice was mild steel flat bar or possibly aluminum flat bar. I was planning on drilling a hole on each side and securing bottom section of crossbar with spacer and then drilling and tapping and securing whole piece to the frame with a M10 or 8.

What do you guys think ? Anybody else have fitment issues with RCI skids? Their designs now in place seem abit weak. Thanks for any help

I have the RCI skid plates. The install instructions specifically says:

"Many vehicles require spacing the skid plate down to clear the exhaust cross-over. Install the supplied 3/8" thick U-shaped blocks, sandwiched between the skid plate and the frame tubes prior to tightening."

Did you get the 3/8" thick u-shaped blocks? If not, contact RCI for them.

 

[Grug556]

I have the RCI skid plates. The install instructions specifically says:

"Many vehicles require spacing the skid plate down to clear the exhaust cross-over. Install the supplied 3/8" thick U-shaped blocks, sandwiched between the skid plate and the frame tubes prior to tightening."

Did you get the 3/8" thick u-shaped blocks? If not, contact RCI for them.

Yeah all is good, the U blocks are installed, its installed at the very bottom of the slot range, still have slight contact. How big a gap did you have between pipe and transfer skid? Also did you have the gap on the two end pieces on underneath wrap around section?

 

[fkheath]

Yeah all is good, the U blocks are installed, its installed at the very bottom of the slot range, still have slight contact. How big a gap did you have between pipe and transfer skid? Also did you have the gap on the two end pieces on underneath wrap around section?

Aha, now I understand all your questions.

First, do you have the stock cross exhaust tube or something other? Most of the OEM cross tubes are flatted on the bottom, as mine is. If that tube is flattened, I don't think there is the possibility of rubbing on the transfer case plate. I have heard that some OEM, and probably most non-OEM cross tubes are not flattened, then there could be some contact. On my 4Runner, with the flattened cross tube, there is plenty of clearance. I did put in the U shaped spacers, however, just to be sure.

Second, I did notice the space (wide) between the RCI cross support and the 4Runner frame rails. I think RCI has to make them narrow to accommodate some manufacturing tolerances in the frame. I put a floor jack under the RCI cross support to ensure the flanges are tight against the frame, then I tightened the bolts really good to eliminate the gap. Since the cross support is aluminum, I'm sure it bends some to take up the space. With the flanges on the cross support tight against the frame rails, there is no way it can move up in the case you hit a rock hard.

I did have to slightly bend the metal brake line tubes because they were touching the cross support. Didn't want to wear a hole in a brake line.

 

[Jeremy556]

Have to space down the skid plate. This helps to move the crossover pipe up higher. Forget what this is, but stolen from someone else on this board, and it's something available in big box hardware stores.

 

[mrblah]

Have to space down the skid plate. This helps to move the crossover pipe up higher. Forget what this is, but stolen from someone else on this board, and it's something available in big box hardware stores.

u bolt in the pic.

I used just a big ass stainless steel hose clamp to do the same thing.

 

[Grug556]

u bolt in the pic.

I used just a big ass stainless steel hose clamp to do the same thing.

So U bolt on the hanger then and constrict the rubber to force pipe upwards? The pipe I have is slightly flat on the bottom end. Other than U bolts the other plan I came up with was to put spacer U shims on the bottom mounting section where the carraige bolts secure it to the crossbar. I thought it I spaced it off maybe 3-4mm that may be enough clearance. I found shim spacers at McMasterCarr that look like they would work. Maybe I should do a combo of U bolt hanger/hose clamp fix along with some spacers to double the lift

As for using the jack to press up the end caps, yes I thought of that, problem was when I did that sure it secured the end caps to the frame rails with no gap, but it also ended up making zero clearance for exhaust pipe and actually pushed it up a tiny bit to further reducing clearance

The word **** should not be 4 letters... its to short to describe the feelings I have when shit gets missaligned like this.. plus its getting cold in the garage again.


Thanks guys, appreciate all the help. Ill go get some more shit and see if I can fine tune this a tiny bit more

Did you guys all run exhaust wrap to insulate against noise, contact and vibration? Or you just bare pipe with a small lift as per above? Thanks

:cheers:

edit to add, yes my crossbraces are OEM. yes they have the square flattened end sections, abit rusty but otherwise looks good. I cleaned them up abit. ONly issue on the passenger side after the M8s snapped off, we re tapped and went with stake nuts in the frame and I switched out from m8x1.25x30 to m8x1.25x 60 (65 was abit to long).

Lastly did you guys just use anti seize, im using nickel as usual, but read abit last night of some saying some RCI stuff vibrated off during driving making a huge mess, they said lack of blue locktite did the mess. You guys use that instead of anti seize on these things?

 

[<<<<]

Aren't you risking cracking exhaust manifold by making that mount rigid?

 

[Humble Leader]

Lastly did you guys just use anti seize, im using nickel as usual, but read abit last night of some saying some RCI stuff vibrated off during driving making a huge mess, they said lack of blue locktite did the mess. You guys use that instead of anti seize on these things?

medium strength thread locker IMO should be used. anti seize HAS been known to sometimes allow threads to back out under vibration and load. I understand the logic of the anti seize "I want to be able to take apart my skids and not have the bolts stuck". Yes, but no. thread locker properly applied will seal from water/elements that can cause rust and a stuck fastener and also bond to prevent vibrations from loosening

as a general rule don't put anti seize anywhere that a repair manual or instruction manual doesn't say to put it.

anti seize works best when you want to take apart things that like to get stuck and thread locker works best when you want components to stay together that tend to want to come apart

 

[Grug556]

Aren't you risking cracking exhaust manifold by making that mount rigid?

Interesting point. What about something half way in between where I only partially squish the rubber hanger block so there is still minor play to eliminate stress cracking upstream

 

[MasterFoo]

found my solution while just reading. awesome forum. clamp the exhaust up by the hanger... I was trying to bend that metal hanger upwards without success... lmao

 

[mrblah]

That’s how I did it for last 6 years. It’s not fully rigid. You only do it to the point the pipe isn’t touching the skid plate.

I also used zip ties to lock to keep the clamp from moving. You can kind of see it in the pic ( 2 black lines)

This ghetto mod has been on this forum since the dinasours roamed the earth.

 

[Grug556]

That’s how I did it for last 6 years. It’s not fully rigid. You only do it to the point the pipe isn’t touching the skid plate.

I also used zip ties to lock to keep the clamp from moving. You can kind of see it in the pic ( 2 black lines)

This ghetto mod has been on this forum since the dinasours roamed the earth:first:.

That be muthar ****ing magic right there!!! thanks Brother!! I got hose clamps o plenty in the garage. This can be done!! :juggle:

 

[Jeremy556]

It still moves plenty. Mine's been clamped that way for about 270k miles, all still original stock, and no problems

 

[Grug556]

It still moves plenty. Mine's been clamped that way for about 270k miles, all still original stock, and no problems

First ill drink heavily...then the work will begin! :whip2:

 

[mrblah]

First ill drink heavily...then the work will begin! :whip2:

so how did the drunkin wrenching go....ROFL:whip2:

 

[Grug556]

so how did the drunkin wrenching go....ROFL:whip2:

Not good... i just woke up. Total failure. We try again in the morning.. I think I need some water right now..ugh :biggrin1: