Drive shaft grinding on gas tank skid?

[wfo9]

I recently put LT springs and shocks on my truck. I noticed the diff/drive shaft ujoint connection would hit my RCI gas tank skid while flexing in one direction (driver wheel tucked). I could reproduce this just around my house... So I notched the gas tank skid and flipped the skid support bolt around to make a smooth transition. This pretty much eliminated any noise that I could produce with urban wheeling.

Then today actually took it to the trails. It was making a horrible noise that kind of took the joy out of it, but I cringed and kept going. I knew it was just chewing on the soft aluminum gas tank skid.

So here is my question. I seem to have two possible routes to fix this.
1. I'm assuming an adjustable track bar (or drop bracket) might allow for the axle to stay straighter at full flex.

2. I could possibly notch the skid more and move the support more forward to allow for more clearance. The fear here is that it could actually still contact the gas tank (but I doubt it).
There is a bunch of room between the skid bracket and the actual tank.

I think this only happens with the sway bar off. The flex was great fantastic, but the noise was hideous. It was also wet today, so an overall less than stellar day.

Curious to hear others experience that have LT, no sway bar, and a gas tank skid. The attached picture shows the contact area....

 

[Jeremy556]

[MENTION=77684]WarnerD9[/MENTION] had the same issue, but IIRC with Shrock Skids. I would just clearance the gas tank skid if that would resolve it. Unless your axle is off center at ride height, an adjustable panhard bar isn't going to help much.

 

[wfo9]

[MENTION=77684]WarnerD9[/MENTION] had the same issue, but IIRC with Shrock Skids. I would just clearance the gas tank skid if that would resolve it. Unless your axle is off center at ride height, an adjustable panhard bar isn't going to help much.

That is sort of what I was thinking, but the only way to find out is on an alignment rack, right?

The tricky part of resolving this issue is seeing exactly what is going on under there at full flex. It was just too wet today to crawl under there. Traction was miserable....

Do you think there is any way the shock mounts are at play with lateral axle shift. I sort of hacked this setup together and the top bushings are a little small.... I'm going to get ICON LT shocks sometime soon.

 

[bimrunner]

Probably can adjust some of that out once your offset LCA are installed. I have the RCI skid and I have no contact at full flex. I doubt your shocks would have any impact even if there was play since the upper and lower arms control the axle placement and not shocks. All the shocks do is act as dampening for the springs.

 

[BlackWorksInc]

I ran into something similar with my RCI skids on my 4th Gen, turns out I installed the carriage bolt backwards and it was just long enough to tap the bolts on the driveshaft flange at the right kind of flex. But that's not what is happening here.

Is it just me or does it look like you can move your gas tank skid forward about half an inch? Because that looks to be just the amount you need to shift it forward for it to stop contacting the edge of the driveshaft flange.

 

[wfo9]

I ran into something similar with my RCI skids on my 4th Gen, turns out I installed the carriage bolt backwards and it was just long enough to tap the bolts on the driveshaft flange at the right kind of flex. But that's not what is happening here.

Is it just me or does it look like you can move your gas tank skid forward about half an inch? Because that looks to be just the amount you need to shift it forward for it to stop contacting the edge of the driveshaft flange.

Yea, (the carriage bolt backwards) is how I had it installed at first. And that noise was insane. After flipping it around it stopped the grinding for all but hard flex off-road.

I have the gas tank skid as far forward as possible with the existing mount holes... I actually already notched the skid as much as I could without moving that bracket forward.

I was thinking I could move the support forward 1/2 inch as well as the mount hole on the skid and cut that section out for clearance. I'm not very worried about trail damage that far back on the tank as the wheel should be on it by that point (unless I do something really stupid, which is not out of the question when trying to climb slimy rocks). I may need to weld a tab onto the mount to or get a new one to use the same hole up on frame/body (I can't remember exactly what it attaches to).

 

[wfo9]

Probably can adjust some of that out once your offset LCA are installed. I have the RCI skid and I have no contact at full flex. I doubt your shocks would have any impact even if there was play since the upper and lower arms control the axle placement and not shocks. All the shocks do is act as dampening for the springs.

Interesting point. the adjustable LCA would allow the axle to move aft a little (which might provide the needed clearance).

As far as the shocks go. Yea, they are not there to control lateral movement, but I think they could still be at play. The swaybar is not there for lateral, but it clearly makes a difference as well. I was thinking wider/tighter upper shock mounts would also have some impact. The trackbar is the main lateral movement limiter. but I'm assuming all the bushings and arms assist.

 

[ATL4R]

I recently put LT springs and shocks on my truck. I noticed the diff/drive shaft ujoint connection would hit my RCI gas tank skid while flexing in one direction (passenger wheel tucked). I could reproduce this just around my house... So I notched the gas tank skid and flipped the skid support bolt around to make a smooth transition. This pretty much eliminated any noise that I could produce with urban wheeling.

Then today actually took it to the trails. It was making a horrible noise that kind of took the joy out of it, but I cringed and kept going. I knew it was just chewing on the soft aluminum gas tank skid.

So here is my question. I seem to have two possible routes to fix this.
1. I'm assuming an adjustable track bar (or drop bracket) might allow for the axle to stay straighter at full flex.

2. I could possibly notch the skid more and move the support more forward to allow for more clearance. The fear here is that it could actually still contact the gas tank (but I doubt it).
There is a bunch of room between the skid bracket and the actual tank.

I think this only happens with the sway bar off. The flex was great fantastic, but the noise was hideous. It was also wet today, so an overall less than stellar day.

Curious to hear others experience that have LT, no sway bar, and a gas tank skid. The attached picture shows the contact area....

I had the same issue. BudBuilt gas tank skid. OME suspension with sway bars. Mine was apparent on fairly quick uphill hard right turns where there was a lot of compression on the left rear suspension. I used my grinder to notch out enough of the skid/skid mount to have enough clearance.

Took me a while to figure out where the actual sound was coming from, but diagnosed it after about the 4th time it happened. It's not a pretty sound!

 

[WarnerD9]

That is sort of what I was thinking, but the only way to find out is on an alignment rack, right?

The tricky part of resolving this issue is seeing exactly what is going on under there at full flex. It was just too wet today to crawl under there. Traction was miserable....

Do you think there is any way the shock mounts are at play with lateral axle shift. I sort of hacked this setup together and the top bushings are a little small.... I'm going to get ICON LT shocks sometime soon.

[MENTION=106176]wfo9[/MENTION] the issue came up for me once I had installed the MT LT kit and control arms. I ended up grinding/cutting the skid section that was rubbing. No longer an issue. Adding the LT kit will deepen the issue. Time to make the (intentional) sparks fly.

 

[wfo9]

[MENTION=106176]wfo9[/MENTION] the issue came up for me once I had installed the MT LT kit and control arms. I ended up grinding/cutting the skid section that was rubbing. No longer an issue. Adding the LT kit will deepen the issue. Time to make the (intentional) sparks fly.

Yea, I already notched it once though. It looks like it just need a little more. This will require the actual bracket to be modified a bit.

One other thing. I found out one of my rear control arm bolts had backed out at the axle connection. Not sure if that was at play with the contact. Need to go find a spot to flex it today and see if it still contacts.

I also realized it actually only happens with the driver wheel tucked. You would think that would push the axle the other way. I do have a slightly bent control arm on the passenger side, so that could also be in the mix.

 

[txbonds]

One other thing. I found out one of my rear control arm bolts had backed out at the axle connection.

Any guess as to why? Was it set to torque? Use any loctite? Just curious as I am planning to go back anddobl check torque on all my suspension pieces this weekend.

 

[bimrunner]

Any guess as to why? Was it set to torque? Use any loctite? Just curious as I am planning to go back anddobl check torque on all my suspension pieces this weekend.

I have found that I need to check torque about every time I regrease. The uppers are what I found want to back out. 49 flbs is the spec and with the additional play of adjustable arms, it seems to work on the bolts a bit. I don't seem to have the same issue on my LCA, but I always check them when down there. Just a good habit if you are max flexing the suspension a lot.

 

[KVA]

I had the exact same issue. Ended up dropping the tank skid and cutting it to match the curvature of the actual gas tank and fabricated my own new brace. I bolted it from underneath but need to get it welded. I also cut/grinded down the opposite side facing the actual gas tank so it wouldn't create any issues.

That said, I have been in contact with Josh over this problem and it sounded like I was the only one who complained as he has no others reporting the problem. He offered me a new skid at a lower cost (or to fix the old one - I pay shipping) but I am concerned a new one doesn't fix the problem. the design must follow the outline of the gas tank closely or when you flex it will grind.

This is what I did...and how I explained it to RCI

 

[STX4Runner]

I had the exact same issue. Ended up dropping the tank skid and cutting it to match the curvature of the actual gas tank and fabricated my own new brace. I bolted it from underneath but need to get it welded. I also cut/grinded down the opposite side facing the actual gas tank so it wouldn't create any issues.

That said, I have been in contact with Josh over this problem and it sounded like I was the only one who complained as he has no others reporting the problem. He offered me a new skid at a lower cost (or to fix the old one - I pay shipping) but I am concerned a new one doesn't fix the problem. the design must follow the outline of the gas tank closely or when you flex it will grind.

This is what I did...and how I explained it to RCI

View attachment 144146

I love it! An MS Paint masterpiece! But seriously, are you now not using a strap at that back corner you had to cut?

 

[wfo9]

I had the exact same issue. Ended up dropping the tank skid and cutting it to match the curvature of the actual gas tank and fabricated my own new brace. I bolted it from underneath but need to get it welded. I also cut/grinded down the opposite side facing the actual gas tank so it wouldn't create any issues.

That said, I have been in contact with Josh over this problem and it sounded like I was the only one who complained as he has no others reporting the problem. He offered me a new skid at a lower cost (or to fix the old one - I pay shipping) but I am concerned a new one doesn't fix the problem. the design must follow the outline of the gas tank closely or when you flex it will grind.

This is what I did...and how I explained it to RCI

View attachment 144146

I never had a problem until I went to the long travel setup. Before that it never hit.

[MENTION=50210]KVA[/MENTION]
Can you post a pic of where you cut...and put the support. It looks like I only need to move the bracket s little forward, but other parts might still hit after that. I would rather not have to keep iterating...

 

[wfo9]

Any guess as to why? Was it set to torque? Use any loctite? Just curious as I am planning to go back anddobl check torque on all my suspension pieces this weekend.

It was totally my fault. My LCA is a little bent and I plan on getting the RCI offset links real soon, so I was lazy and did not use thread locker. Plus, I put grease on the bushing :doh: I figured no big deal for a week (they were torqued to the proper spec 98 ft lbs. However the nut was gone within a week. It is a flange nut, so it is very susceptible to backing out.

 

[KVA]

I love it! An MS Paint masterpiece! But seriously, are you now not using a strap at that back corner you had to cut?

I fabricated a strap using the same 3/16th gauge steel that connects at the same mount point on the truck, but moved the bracket connection to the bottom of the skid - not great, but no different than some of the other skids. Ultimately I will simply have it permanently welded onto the skid and the bolts removed. It bolts from the inside out...so the nut is on the outside and have been grinded down so the bolt does not extrude past the nut.

 

[KVA]

I never had a problem until I went to the long travel setup. Before that it never hit.

[MENTION=50210]KVA[/MENTION]
Can you post a pic of where you cut...and put the support. It looks like I only need to move the bracket s little forward, but other parts might still hit after that. I would rather not have to keep iterating...

I can take a pic. Ultimately there is space there under the gas tank as it curves, but you will need to cut the skid where it is bent up to attach the support on that corner - hopefully this make sense?

 

[KVA]

I never had a problem until I went to the long travel setup. Before that it never hit.

Mine isn't long travel in the rear, but whenever you would take a right-hand turn up an immediate incline it would rub/flex. Drove me nuts and thought originally it was my sliders until I started removing everything to figure it out.

 

[harper7]

My rear diff/driveshaft flange was hitting my Budbuilt gas tank skid too and I trimmed it a couple of years ago.Was posted in a thread somewhere but couldn't find it.:fear:

Before and after shots

after trimming