KB Voodoo Bed Rails + Diamondback Install (Detailed Writeup)

Background
My primary motivation for installing the KB Voodoo bed rail caps and tailgate cap was to create a dust-proof and water-proof bed, in conjunction with my Diamondback bed cover. So this writeup will be focusing on the steps I took to ensure the bed is sealed. I haven't seen a post that focuses on this exact use-case, so here goes.

I've had this bed cover for a few years since I got a great deal on Craigslist, but I've been extremely disappointed with the way it seals (or in reality, doesn't seal) on the 2nd gen Tacoma bed. The main issue is the tailgate cap that sits on a different plane than the bed rail caps (nearly 3/4" difference!). Diamondback tack welds an additional strip of diamond plate onto the tailgate panel, but (at least on the second-hand cover I have) the strip is not long enough, resulting in huge gaps where the gasket doesn't reach at both ends of the tailgate. In addition, even if the seal was complete, the gaps between the tack welds would allow dust to come straight into the bed, above the gasket. The KB Voodoo bed rail caps sit lower than the OEM plastic caps, and should nearly eliminate this height difference (more on that later).

Beyond that, underneath the plastic bed rail caps are many holes that open straight into the wheel well, allowing dust and road grime into the bed. Underneath the OEM T-track, the metal bed rail wraps over the edge of the composite bed, but there is no gasket, so dust and water can sneak in here as well.

In addition to the bed-sealing angle, I purchased my cover used and did not receive or know about the bed rail shims that prevent the plastic OEM caps from being crushed. So long story short, my plastic bed rails have been crushed and it's always bugged me that the caps were wavy from the clamping force of the cover.

Enough talk, let's get into the install process.

KB Voodoo Bed Rail Cap Install
Begin by removing the plastic OEM bed rail caps. Then you'll want to hose or wipe down the exposed bed rails.



Note all the dust that has accumulated on the bed rail. There is nothing preventing this from coming into the bed. Also note the dust on the inside of the bed rail (this is underneath the T-track), and what you can't see, but you guessed it, more dust between the bed rail and the composite bed, underneath the T-track.



Prep the bed rails for the adhesive with rubbing alcohol. KB Voodoo sends 1/2" x 1/16" double-sided foam tape to be placed along the outer edge of the bed rail, acting as a spacer to prevent the aluminum caps from coming into contact with the bed rails. Since I wanted to ensure dust cannot enter the bed from underneath the cap, I needed to lay down an additional line of weatherstrip on the inside edge (between the holes and the bed). I ended up purchasing 1" x 1/16" foam weatherstrip (not double-sided tape). The aluminum caps are bolted in place which holds them tightly against the foam, so there is no need for the foam to be permanently stuck to the cap.



Since the inner strip of foam covers many of the holes, I cut shorter strips to use as the outer spacers, so as not to plug all the holes in the rail, to allow for drainage since water will certainly get under there.







Before bolting on the caps, there are a few more places that must be sealed up. There is a large gap at the tailgate end of the bed rail that I closed with Gorilla tape. This will then be clamped over with the aluminum cap.



Right next to that is the beginning of the section where the bed rail overlaps the composite bed, with no seal in between. Since I had plenty of the weatherstrip, I cut a short section and wedged it between the two layers.



At the front of the bed is another gap that I covered with tape.



The most difficult part to seal is the long section underneath the T-track, where the bed rail and composite bed overlap. I ended up using a flathead screwdriver to pry the bed rail away from the composite bed slightly to provide enough room to slide the weatherstrip halfway underneath (I was using 1/2" wide weatherstrip here). I could have had an easier time by just taping over this section as well, but I felt better about the long-term viability of the foam.



Here's a closer look at the end-result. Again, this will be clamped by the T-track, so should provide a tight seal.





And here's a side-view in case the problem and solution weren't apparent from my ramblings.



Now here is one last fun bit that Toyota must have engineered just to spite me. Notice the small indent at the end of the composite bed bulkhead.



I used 1" x 1/8" foam weatherstrip to seal the bulkhead, and I did my best to wedge it into the gaps on each end. I can see a sliver of daylight from inside the bed at each corner. I'm not overly concerned about dust and water from these small gaps, but if it isn't acceptable, I'll probably fill those gaps with RTV silicone instead.





Now that the prep is complete, bolting on the caps themselves is the easiest part of the entire process. Having an extra set of hands will be helpful to hold the T-track in place while lining the first few bolts up, but it is easily doable by yourself. For the final two bolts at the tailgate end, I found it easiest to kneel on the cap while tightening the bolts to ensure the cap is at the proper height, resting on the weatherstrip.

Here are some photos of the KB Voodoo bed rail caps with the OEM tailgate cap. Nearly a perfect height match! The Diamondback cover's weatherstrip now seals against the tailgate without issue.











KB Voodoo Tailgate Cap Install
Next up was to finish this project and match the look of the bed rails by installing KB Voodoo's tailgate cap.

I made some minor adjustments to the typical tailgate cap install as well. First I elected to cut the provided 1/4" weatherstrip into short sections, again to keep the drain holes free.







Then, once again in the spirit of keeping dust out, I used leftover 1/2" x 1/16" weatherstrip running the entire length of the tailgate. The tailgate cap is clamped tightly against this when it is bolted on, which should result in a strong seal.



With this extra seal in place, the cap fits VERY tightly. After fighting the right side, then the left side, then the right side again, I found it easiest to start with the middle bolt, and work my towards the edges of the tailgate.



A closer look at the extra weatherstrip I added to the tailgate cap to prevent dust from finding its way in.



Now... the problem. The astute observer might notice that the tailgate cap is no longer on the same plane as the bed rail caps (though it is advertised to match the height of the stock cap). 1/8" of an inch off by my measurements.



Still, I had some hope that this would be "close enough" and the weatherstrip would seal against the tailgate cap. Unfortunately, this was not the case.

Now I had a couple options. The obvious option would be to go back to the OEM cap and call it good. But I had already purchased the KB Voodoo cap and prefer the look and solidness of the aluminum, so I started working on a solution.

The foam tape provided by KB Voodoo to act as a spacer between the metal tailgate and the tailgate cap is 1/4" thick.



I had just got some "compression limiting strips" from Diamondback because I thought they might be useful when I carry kayaks on top of the cover. Coincidentally, these ended up being 3/8" thick hard rubber strips complete with 3M adhesive. Just what the doctor ordered to give me the extra 1/8" on top of the tailgate.



But there was still one more hurdle to clear. Would the holes in the tailgate cap have enough play to allow the cap to slide up an additional 1/8"? Fortunately, the holes are oversized quite a bit, probably twice the bolt diameter.



But as soon as I pulled out one of the bolts I noticed a problem. The tailgate cap bolts have a large shoulder that limits how far the cap can slide up. Not to worry, the slightly shorter bolts that hold the rest of the plastic tailgate cover in place just use a washer and don't have that large shoulder.



Just as before, I cut the rubber strips into small sections to keep the drain holes clear while still providing support across the width of the tailgate.



Next, I lined up the cap with the tailgate, making sure the holes were centered (use the center hole to help with this since it is the smallest). Then, slowly drive in the bolts, I started in the middle and worked towards each side, alternating left and right. The fit is now even tighter than before, the bend in the tailgate cap does contact the inside of the tailgate, but I'm not overly concerned because these surfaces are never visible. I might go back and add some thin foam tape to act as a seal if an dust manages to sneak through here, only time will tell.



The outside of the tailgate is still protected by the foam tape pre-installed by KB Voodoo.





Now the grand reveal!





That's about as good a height match as I can imagine!

Diamondback Cover Install
To prepare for the new bed rail and tailgate caps, I had to remove the extra strip of diamond plate from the tailgate panel of the Diamondback cover. It is impossible to get a saw onto the welds due to the uneven surface of the diamond plate. I ended up using vice grips and bending the strip back and forth until it broke off at the welds.

Then I set about trying to grind down the welds. Using the tools available, I grabbed my Harbor Freight rotary tool and got to work. To nobody's surprise, this was a slow process and one that didn't result in a perfect result. An angle grinder would surely provide much better results, but this was good enough.

Next I removed and replaced all the weatherstrip on the cover since it had been clamped down too tightly and was fully compressed and deformed to the point it would not return to its original shape. I won't go into this in detail, but will say that a heat gun is a "must".

The next issue I identified is the cap clamps used by Diamondback. If you search the interwebs, you'll find many complaints with these clamps. In my case the primary issue is that the clamps are designed to bridge a larger gap than I now have between the cover and the T-track (due to replacing the taller OEM bed rail caps). This is exacerbated by the fact that it is nearly impossible to keep the clamps straight as they are tightened down.



Now the top section of the clamp ends up tightening to the point where it is alongside the hex head of the bolt. Once this happens, a socket can no longer fit around the hex head (and there is not sufficient space when tightening this down in the bed to fit a wrench onto the bolt).



I ended up cutting 1/4" off the top section of the clamp (I should have cut closer to 1/2" off, but this ended up being just enough).





This gave me enough room to tighten the clamps "just enough". Diamondback now specifies 4-5 ft-lbs, which does not seem like much, but I didn't hit 5 ft-lbs on my torque wrench before stopping because I felt the weatherstrip was compressed enough to allow for a uniform seal around the entire bed without requiring excessive force when latching the Diamondback panels.

I'll probably play around with the exact locations of the weatherstrip on the center section of the Diamondback cover. Many folks have had issues with water entering the bed here when the panels are opened, and I imagine I might see these issues especially now that the bed rail caps are smooth, rather than the dimpled surface of the OEM caps. For now, I went with the large weatherstrip supplied by Diamondback on the outer edge, with smaller diameter weatherstrip on the inner portion to give the clamps some resistance and hopefully keep that water out.



Additional Sealing
In addition to the sealing I performed while installing the caps, there are a few more spots where dust and water gets in easily. The four bed cubbies are the worst offenders. I never really used the cubbies anyway (since they fill with dirt and grime), so I just removed the covers and taped over both the inside and outside of the large rectangular holes. For the drain holes (both in the cubbies and the bed itself), I popped in 5/16" plastic hole plugs from the hardware store so that I can easily remove them if I have to wash out the bed. The last gaps I found were at the base of the bed near the tailgate, which I used a bit of RTV silicone to fill.

I also installed an ESI tailgate seal kit, ensuring that the seal reaches the top of the bed rail/tailgate caps.



Finished Product
Though it took a bit of effort to get just right, I could not be happier with the end product. I'm looking forward to seeing the real results when I hit some dusty trails later this month.

 

I used KB Voodoo bed rails for exactly the same purpose a four or five years ago when I modified my Gen 1's Mountain Top checkerplate aluminum tonneau (from the Danish company that for a time made covers for Gen 1 trucks) to fit onto the Gen 2 bed. It's not perfect -- I wish the cover were a centimeter wider -- but it works well and I love it!

I didn't modify the original plastic lip on my tailgate -- the plastic tailgate and the KB Voodoo bed rails were very close to a flat deck all around. Your sealing efforts, @ripcityhandyman, were much more rigorous and impressive than mine, but TBH I don't have huge dust ingress issues.

Diamond Back, with their hinged design, doesn't work for me 'cause I usually have a fork-mount Thule bike tray on the tonneau. Pity, for I really like their stuff otherwise!

 

@4xdog, I actually saw some of your posts when I was researching the KB Voodoo rails. I'm surprised more folks aren't using them for this purpose (matching tailgate and bedrail height).

I'm excited to hear you don't have any issues with dust. I probably went overboard, but I've had such a problem in the past that I wanted to leave no doubt this time!

 

I do get some dust, @ripcityhandyman, but not enough to motivate me to make any changes.

I’m surprised too that more people don’t use the KB Voodoo rails for this. Or even that KB Voodoo doesn’t promote it. Seems like it’s the best use case for their product.

 

Gotcha. I doubt much of the work I did to seal the bed rails was necessary. But fortunately, I think the main points of dust ingress are also the easiest to seal. The following are the largest entry points for dust, as I see it, in descending order:

1. Bed cubbies. The large slots in the bed cubbies open straight into the wheel well, a direct line from the tires churning up dust into the bed. I didn't use these cubbies anyway, so it was easy to tape over the large slots. If you use them, I believe there is someone on TW printing plugs that allow the covers to be used.
   
2. Bottom and sides of tailgate. The ESI tailgate seal does a terrific job of sealing these gaps. I've had mine for three years and it is doing great.
3. Drain holes (both in the bed and in the back of the cubbies). These are a distant third on this list, but since they are so easy to plug with 5/16" hole plugs I think it is worth doing.

Since I already had much of the bed taken apart I felt it was worth my time to do the rest that I documented above for completeness, but I firmly believe this short list is the source of 99% of dust in the Tacoma bed.

I totally agree. The problems caused by the mismatch in bed rail and tailgate height on the 2nd gen Tacoma aren't talked about nearly enough, and these bed rails fix that.