Project Mini - Whittling Down the Bed

Http://www.4x4wire.com/toyota/tech/project__bobbed

Short Cuts

Author: Jay Kopycinski April 2000

Our '88 project truck

So....you've decided your truck is a wee bit too long and you'd like to shed a few inches off the rear? Sounds like you need to bob your bed. Here I'll explain how to go about shortening your truck for better clearance and greater departure angle. There have been some good articles in the past on bobbing. I hope to add just a bit more info to the tips presented in those to help you on your way. The job is not that difficult it just takes some patience and careful measuring and cutting. Like my dad always told me, "Measure twice and cut only once, not the other way around".

Planning the Surgery

The truck we used for this project is the '88 Xtra Cab shown here. We started by removing the bumper, license plate, taillights, tailgate, and inner bed panels. Before we bobbed the bed we wanted to trim the rear fender skirts for added clearance on the tail end. We applied some masking tape over the areas we expected to cut. This was done for two reasons: it provides a good surface for marking your cuts and it helps protect the paint when you're dragging a saw across the body.


Leaving the plate mount....for now	About to trim the lower skirts to gain clearance

When trimming the rear, I like to be able to mount the bumper as high as possible. On a truck, the bumper needs to remain about one inch below the bottom edge of the tailgate to allow for clearance when the tailgate is opened. As such, we trimmed all the body panels behind the tires about ½ to ¾ inches below the tailgate. When you trim under the taillight pockets you will also have to trim the inside reinforcing panels as well. Remember when doing this you will have to leave some of the license plate mount unless you intend the relocate the license plate up higher on the tailgate or bumper.

Methods

Measuring forward from tailgate for our first cut

I have tried several methods of cutting sheetmetal and each has advantages and disadvantages. A metal cutting blade in the circular saw makes nice straight cuts, but leaves the edge a little ragged. Saber saws or large reciprocating saws work well and cut smoothly with fine tooth metal blades. You just have to hold the saw a little steadier to get a nice, straight line. Die grinders can also be used in some places. I typically use a combination of these tools depending on the particular area I'm cutting. In any case, a little cleanup with a fine metal file will help smooth the metal edges.

Marking vertical lines for the first cut

So, we sliced off the bottom areas as you can see in the next photo. Next, we marked our first bed cut. We clamped a scrap piece of aluminum angle to the top of the bed and used a drafting t-square to draw our first cut line on some masking tape. This first cut was made about 7 inches from the inside rear of the bed or tailgate. This keeps some of the straight bed panels with the tail section and also helps avoid cutting the tabs that hold the inner bed panels.

Getting Started

Making the first cut

With both sides marked for the first cut, we made the vertical cuts. To make the horizontal cut across the bottom of the bed, we used a straight edge. We took a scrap piece of thin steel flat bar and cut it to length to fit across the inside of the bed. We tack welded it in place and used it as a guide for our saw. Be sure to watch for wires and frame rails under the bed while cutting. With the bottom cut made, the tail section of the bed was removed. No turning back now....

Second cut complete

This is when we made our second cut lines. Since the main idea was to get the panels to fit back together as closely as possible, we used the actual resulting cut line from the first cut to measure for our second cut line. Simply measure forward from the rear edge of the bed and mark your second cut line. We decided to remove 14 inches from the bed. The second cut was made the same way as the first, and the middle section of bed removed.

Cutting the frame rails

With the bed cut down, you'll want to decide where you want to cut the frame rails. For our bob, we cut off about 7 inches of the frame rail. We used a metal blade in a circular saw to make the cuts. For future reference, we'll need four holes with which to mount our new bumper. Two will be provided by the existing rectangular holes just forward of the shackles. The other two will be drilled in the frame rails. Each bumper mount hole will also be sleeved with a piece of tubing to prevent crushing the frame rail when the bumper bolts are installed.

Reassembly

Putting it back together

To put the bed back together we aligned the two bed sections and held them in place using some wood blocks and c-clamps at the top bed rail. Check for fit and alignment and adjust or grind small areas as needed. When the mate looks good, you're ready to tack weld the sections together. However, first we used a grinder to remove the paint near the edges of the mating sections. Place a tack every inch or so, making sure the panels mate evenly as you go. Tack both sides and the bottom of the bed.

Finishing up the welding on the bottom of the bed

You can finish the body welding as you please. I used a 110V mig welder. I'm no expert welder, so it took me quite a while. To make welding the sides a little eaiser I added some narrow sheetmetal strips to the inside of the bed. This helped reinforce the bed sides and made welding easier due to less burn-through. Go slow and do not spend too much time in any one area without letting it cool some. This will help reduce warping of the panels. Luckily, the shape of the panels causes slight metal pull of the weld joint inward instead of outward.

When the welding is complete, follow up by grinding the welds flush or just below the level of the panels. Body filler can be used to finish the job and provide a smooth finish.


Here are the trimmed inner panels	A quick look at the final bobbed bed profile	Frame rails trimmed, ready for a new bumper

The inner body panels can also be shortened and reinstalled. Simply mark and cut to length, discarding the tail piece. If you've cut your bed similar to the way I described above, you should find the mount holes will work out fine.

When the bed is bobbed such as this, the rear-most bed mounts are removed. This reduces the number of bed mounts from eight to six. However, spacing works out well for the remaining bed. The taillight wiring will now be longer than necessary. This can either be spliced and shortened, or simply bundled and tie-wrapped under the bed.

If you'd like to see my original article when I bobbed the bed on my truck, just click here.

Now, with a shorter bed you'll find getting around obstacles a little easier and the tail won't drag on the rocks like it used to. Besides....it just looks cool too!

Thanks for reading!