Radiator drop brackets for a body lift

This is a design for radiator brackets used to lower the radiator on a vehicle to compensate for a body lift. With a body lift, the body or cab is raised up off the frame. Since the radiator is often attached to the front of the body at the core support, it will raise up as well. If the radiator fan is mounted on the engine, that fan may not line up with the shroud on the radiator. Likewise, radiator hoses may become kinked or collapse if they are pulled too tight.

A solution, for radiators that attach to the front of the body via bolts through the flange on the radiator and holes in the core support, is to install drop brackets to lower the radiator. This simple bracket design uses a stud or screw on one end of the bracket to attach to either the radiator flange or the core support.

On Toyota pickups, 4Runner and similar models, there are 2 basic designs. On the earlier trucks, there are nuts spot welded behind 4 holes in the core support. The radiator flanges likewise have 4 holes through which bolts pass to fasten the radiator to the core support. Later model vehicles swap the location of the welded nuts, placing those on the radiator flanges with plain holes in the core support.

In either case, the bracket is fastened to the plain hole via s stud or screw and then fastened to the threaded hole with the original bolt. See the information on the web pages below for more detail: https://www.4crawler.com/4x4/ForSale/BodyLiftKit.shtml#RadiatorBrkts https://www.4crawler.com/4x4/ForSale/Docs/BodyLift_HowTo.shtml#Radiator

This OpenSCAD file can generate brackets with 1-3 holes in addition to a hole for the stud or screw. Typical heights are 1" up to 3" drop. For that last hole, it can be made plain (for a press-fit stud), or with a chamfer (for a flat head screw for for a welded in stud).

One would not use a 3D printed plastic bracket as is, but it could be used as a drilling template to make brackets out of something like 1/8"x1" steel or aluminum flat bar. Or you can print a part with a stud (plain or threaded - uses the threads-scad/threads.scad library) to give to a fabricator to show what the finished part should look like. It could also be used for a CNC router to cut brackets out of sheet aluminum, for example. Or it could be used on a CNC plasma cutter to make blanks in steel. In our case, we use a drilling template to mark steel blanks as needed. Holes were drilled, a chamfer was added to the end hole and a stud was welded into that hole.

Typical thread sizes used by Toyota are M8-1.25. For ease of fabrication, 5/16" studs can be used, about 1" long. Plain steel threaded studs, or press-fit studs (https://www.mcmaster.com/products/studs/studs~/press-fit-studs~~/).

The 1st photo shows, top to bottom, a 3D printed bracket w/ threaded stud, a plain 3D printed bracket, a 1.5" bracket, in steel, cut to length and marked for drilling and finally a 1" bracket with welded stud along with the washer and nut for that stud as well as a button head M8 screw to attach the bracket to a radiator with a threaded nut in the flange.

The 2nd photo shows a bracket with a chamfered hole with a flat head screw.

The 3rd photo shows a simple jig for welding a stud top the end of a bracket. Simply one or more holes in a block of aluminum that's a little thinner than the length of the stud. Drop a stud into the aluminum block and lay the bracket over it, chamfered side up. Then, it's easy to weld the stud in place.

The 4th photo shows an alternate bracket design that involves no welding.  A length of 1" x 1/8" aluminum (or steel) flat bar is pop-riveted to the radiator flanges to fill in the cut out sections.  Cut the flat bar long enough to fit the offset holes which can be marked and drilled to match the OEM bolt hole spacing. 

These brackets are also useful for relocating attachment points for hoses, wires, wheel well liners, etc. that may be affected by a body lift.

Category: Automotive