| Figure 1 ||Figure 2 ||Figure 3 |
Until the Chrysler Group finalized a procedure recently, the lower radiator crossmember could not be replaced unless one of the fender and shotgun rail assemblies was being sectioned. Now, if just the lower radiator crossmember is damaged, it can be replaced without sectioning the fender and shotgun rail assemblies.
There are different configurations of this lower crossmember, depending on the model and model year. The 2006 and later Durango and Ram, for example, have slotted holes across the front (see Figure 1). The Dakota has a lower bar attachment that must be removed at least on one side before removing the crossmember. This procedure will be shown to replace the damaged front lower radiator crossmember on the 2004 Durango shown in Figure 2. This procedure can be modified for the other designs. The replacement part for the Durango that is shown includes a support bracket for the A/C condenser (see Figure 3).
The procedure requires disconnecting the battery and disarming the passive restraint system. Next, parts are removed or shifted out of the way to access the damaged crossmember. These include the bumper assembly and a wiring harness casing clipped to the top of the crossmember. The upper crossmember is also removed. On some vehicles, it is necessary to remove the A/C condenser and radiator for proper clearance of the reciprocating saw blade and GMA (MIG) welding gun. The repair joint will be welded on all four sides.
Measurements are taken to determine if the collision caused the rail assemblies to move inward or out of alignment in some other way. Dodge provides point-to-point underhood and front upper body specifications.
A blanket is used to protect adjacent parts from the saw blade and cutting sparks.
Damaged part removal
Since the crossmember is sleeved into each shotgun, the only way to remove it is to cut it in two and pull each section out separately. It is not critical where the vertical cut is made, but it is easier to remove the halves if the cut is made at an angle. The replacement crossmember will be similarly installed.
Once cut, the two bolts in each shotgun rail end are removed. The two halves can now be shifted laterally and removed one at a time (see Figure 4).
| Figure 3 ||Figure 4 ||Figure 6 |
Installing the replacement part
Preparing the replacement crossmember begins by cutting it into two pieces at a 45-degree angle. A combination square is used to scribe the cut line, which is approximately in the center of the piece, avoiding a hole in the crossmember bottom (see Figure 5).
Similar to all recommended sectioning joints on hydroformed parts, Dodge requires an insert for the butt joint. The 25 mm wide insert is cut from an undamaged portion of the original crossmember, again at a 45-degree angle (see Figure 6). The insert is cut into two pieces at opposite corners so that it can be trimmed and inserted into the end of one of the crossmember halves.
The ends of each replacement part half are prepped by removing the E-coat 25 mm on both the outside and inside. Coatings are also removed from the insert. No weld-through primer is applied.
With the insert tack-welded into one of the halves, the crossmember pieces are inserted one at a time into the shotgun ends and pulled together at the new joint, leaving a root gap the thickness of one layer of metal. The bolts are loosely installed. A pronged locking pliers is effective for holding the crossmember in alignment while tack welding at the center. Next, the fasteners are torqued to proper specification.
The butt joint weld is made completely around the joint, using a skip/stitch method to minimize heat buildup. The welds are ground flush and the area is prepared for priming and refinishing. Corrosion protection is applied to the interior of the crossmember using a spray and wand system by inserting and drawing out the wand in one of the front access holes.
As mentioned in the introduction, this procedure can be modified for the different lower crossmember designs. For example, the angle that the replacement crossmember is cut does not have to be 45-degree, and can even be a straight cut. An angular cut, however, will allow easier installation of the replacement part. The insert is not for structural purposes; it is for making the butt joint easier to weld. So it too can be modified or an open butt joint can even be made.
There is now a replacement procedure for the front lower radiator crossmember on the 2002 and later Dodge Ram, 2004 and later Dodge Durango, and 2005 and later Dodge Dakota. The crossmember can be replaced without removing one of the fender and shotgun rail assemblies. The procedure involves cutting the replacement crossmember at an angle and creating a 25 mm long weld backing insert from an undamaged portion of the existing crossmember.
More procedures on Chrysler Group vehicles can be found in the following I-CAR program: Collision Repair Overview for Chrysler, Dodge, and Jeep Vehicles (DCX01). Search for a class near you at www.i-car.com.
The following classes are available online at www.i-caronlinetraining.com: Dodge Durango Front Frame Tip, Upper Fender Rail, and Shotgun Rail Replacement (DUR01), Dodge Durango Rear Frame Tip Replacement (DUR02), Chrysler 300 Lower Rail Partial Replace-ment (CHR01).
For comments or suggestions on the Advantage Online, please contact I-CAR Senior Instructional Designer Bob Jansen at firstname.lastname@example.org .
This article first appeared in the I-CAR Advantage Online, which is published and distributed free of charge. I-CAR, the Inter-Industry Conference on Auto Collision Repair, is a not-for-profit international training organization that researches and develops quality technical education programs related to collision repair. To learn more about I-CAR, and to subscribe to the free publication, visit http://www.i-car.com .