Seems like I have been involved in several conversations on stretching the rear here lately and I have been planning on doing it for some time (I actually got the frame pieces to accomplish the splice back in Mar or Apr of this year and they have just been sitting on my shelf). Anyway, after our wheeling trip in Nov, I had a conversation with my normal wheeling friends and due to holidays and family stuff most of them said that they would not be able to wheel again until January. So that gave me a 6 week window of no wheeling opportunities. Now I just needed to find time in the garage. Well, my wife left to visit her sister in east TN last Tuesday and I stayed home to be with our son for Thanksgiving. Lucky for me, my wife would rather her son not be alone even though I don't think he really cares. Anyway, I now had a window to tackle the rear stretch.
I went into this with the following mindset:
1. Try to salvage as much breakover angle as possible, which meant to maintain the current tire to frame side control arm distance. I didn't want to leave the brackets at the same location and extend the control arm lengths because this would put the parts that hang down closer to the middle and reduce the breakover angle. This also allowed me to utilize my current control arms.
2. I wanted to greatly improve my departure angle, so I wanted the tires to be at or slightly past the rear bumper. I also wanted to raise the rear bumper if possible.
3. I am not a welder by trade and I don't have any formal welding training, so I am always fearful of my ability, so make sure it is a good design that offers as much as strength as possible, I also don't care about looks. So that meant external splice members, because the distance (d) is squared.
4. Keep the cost down and reuse as much stuff that I already had (so control arms, antirock, metal that I had laying around, no new tools, etc....).
5. Try to get it done in minimal amount of time as possible. I have other obligations, especially during the holidays, I also have other hobbies that I don't want to suffer.
I already had a genright 4 link control arm brackets installed in the rear and my current skills, ability, and tools really didn't have me cutting them off and reusing them. I could have cut the frame just in front of the brackets and then made my splice there, and that was doable, but not with my ability, it would have taken more precision and skill to fab all the parts. So I decided to not waste the time and energy to remove them and just leave them installed where they were and just cut off the actual lower brackets so they didn't hang down. Then purchase a new set of GR control arm brackets ($149 for the weld your own version) and install them.
I also wanted to resuse my rear bumper and I did not want the torque box and bumper to stick out as much as it did. That meant relocating the rear body mounts.
With all of that in mind. I decided to cut the frame approx 4" behind the current GR bracket which gave me 3.5" of straight frame on both sides for the splice. I would then utilize the new GR bracket at the fwd cut/splice location as part of the splice itself. That would put the new GR bracket and control arm brackets approx 7.5" aft of the existing locations and thus I would add a 7.5" splice section and move the rear axle 7.5" and thus the control arm lengths would stay the same and the relation of the brackets to tire would stay the same.
Conceptual plan in place. I waved as my wife pulled away in the Subaru tuesday morning and immediately started the actual process.
Cutting the frame and removing it was actually super easy. Fabbing up the splice pieces was also very easy. The body mounts had me thinking for some time. I basically had to relocate the aft two body mounts and I had to figure out a way to pick up the two bed mounts which now.
Bed mounts - With the 7.5" stretch the actual bed mounts were right in line with the spring perches and that reduced the space to add a cross member. So I added a 1-3/4" tube just in front of the spring perches and then added the mounts off of that tube.
Aft mounts - I relocated them to the aft channel, which is right in front of the torque box. When I cut the outer torque boxes off, I salvaged the nut plate and cut a slot and fished them up into the channel and then tacked them in place. I cantilevered the brackets off the frame and done. For the actual torque box, I cut it similar to the existing end which allowed me to bend over the aft side and close off the box and then I welded the box shut.
I spliced in my existing bumper and moved it up approx 5/8" closer to the body.
Cycling the axle with no tires installed had the upper control arm contacting the body and the added 1-3/4 tube at the same time that my upper axle side control arms also touched the body. So I had to add a little bump stop, was hoping not too, I could probably come up with solutions for each of those contact points, but with all three at the same time I took it as a sign to just add the 1/2" of bump and keep going.
Installed the tires with springs to verify my ride height so I could then measure for new drive shaft and also figure out the antirock install. First look and I like it!
At this point it was Thursday night and I have basically worked three days in the garage. I decided to stop and go Mt Biking for two days to try and find a spark and help motiviate me to get into shape. So I headed down to Alabama and rode Fri at Oak Mtn in Birmingham and Tannehill in Bessemer on Saturday.
Home Saturday night so I could tackle the antirock on Sunday, my goal was to get it on the ground by Sunday night.
Tires back off and I figured out the antirock.
Back on the ground with springs, shocks, and antirock is where it sits today.
I still need to figure out a bunch of stuff (brake line, parking brake cables, rear tail lights, and tailgate mount, etc....) but progress was made. Probably won't work on it again for a few weeks, Wife says I need to help get all the xmas decorations up this week and weekend. My oldest son is coming home for a few weeks starting Dec 13 and she wants everything done before that.