Frame Endcap Mod for Winch Bumpers
Doing the "End Cap Mod" for more strength with an ARB Bullbar/Winch installation
http://www.nwtoys.com
So you are thinking about adding an ARB Bullbar and winch to your Tacoma/4Runner. Good call. The ARB bumper is a great product and a great platform for winching. However... Toyota never anticipated that you would be putting that kind of pulling strain on the bumper mounts and in their infinite wisdom, ARB did nothing to beef that mounting system up to support the forces of winching.
If you install an ARB and winch on a Tacoma or 4Runner with the stock bumper mounts, you WILL damage your rig with heavy winching. On the Tacoma's, the front end cap takes most of the winching load and begins to distort, placing the load on the bolts that run vertically through holes in the frame, eventually tearing the frame. On most 4Runners, the frame doesn't even have the end cap, so you go straight to tearing the frame :(
When this happened on my Tacoma, we put our heads together in the WATTORA garage and found a solution. I have one of the first true "Tacoma" bumpers that was imported into the USA, in fact it was the second one sold here. Before the Tacoma bumper arrived, people used the "Prado" bumper, which is larger and never quite looks right to my eye. But, the mount system on the Prado bumpers, while not being air bag compliant, that is, it might make your airbags go off too soon, too late or not at all, had what seemed to be a more sturdy mount system. The Tacoma bumper is supposed to be air bag compliant and not change the reaction of the sensors, but it's mount system leaves something to be desired. ARB does not make a 4Runner bumper, but since the frame is the same as the Tacoma in the front, enthusiasts use the Tacoma bumper. Since I got mine, it has seen some heavy use and so I was one of the first to suffer the endcap blow out. Since then, EVERY Tacoma/4Runner I have seen with a winch installed has shown some damage to the frame as a result of winching. Since we started doing the endcap mod, none of those rigs has seen any damage and they all have noticed a more "solid" winching experience, with less movement of the bumper in normal use.
Here's some shots of the problem
As you can see, the end cap has distorted from the winching loads. This in turn begins to put a load on the vertical bolts, which are really just for positioning and should never see winching loads.
The fix;
First, we remove the stock end cap;
Next, we cut and shape a piece of angle iron to fit. The angle iron covers not only the area formerly covered by the end cap, but also slides down the inside of the frame for extra strength. Notice the stock mount nuts inside the frame. At this point, you might want to take a moment to improve upon the tack welds Toyota uses to hold those in place. It's a serious pain when they break loose. It's a bear to weld in those close quarters, but it's worth it.
Next, we drill the new end cap to accept one leg of a u-bolt. Another variation is to drill the new end cap, then weld a nut on the back so that a bolt can be put through from the front.
Notice how the edge of the angle iron is shaved in the last picture to slide past the stock nuts that are tacked within the frame.
Next, drill a couple of holes in the side of the frame at a location that will allow the angle iron to show through. You will be applying a couple of "rosette" welds here for a bit of added strength.
Finally, we weld the whole mess into position, including the rosettes.
After a bit of clean up and some paint, you have new, MUCH more sturdy end cap that will take the loads that high power winch can dish out.
Now, just finish up the other side and reinstall the bumper.
Happy winching!
-Rob (WATRD)
PS: We have done a bunch of these this way, but recently, we have sort of branched out by doing the mod a little differently. If you drill out the "L" piece, then weld a nut on the back, instead of welding the leg of the U-bolt directly to the plate. That allows a slightly cleaner install, without the "bull's horns" sticking out that I have. However, it gives you less to line the bumper on, so it's more difficult to put back on. Functionally, it seems the same. Up to you, but I wanted to mention it.