K 2500 Truck 4WD V8-379 6.2L DSL VIN C FI (1989)
Cross-Member: Customer Interest
Body - Extreme Frame Flexing
GMC NUMBER:
90-02-35
GROUP:
2-Frame-BumperSheet Metal
DATE:
February, 1990
CORPORATE
NUMBER:
962004
SUBJECT:
FRONT FRAME CROSSMEMBER CRACK
MODELS:
1988-90 C1,C2
Some 1988, 89 or 1990 C1, and C2 light trucks subjected to extreme frame flexing in severe duty may experience front frame cross member cracking.
The crack may start at the bottom corner of the right lower control arm pocket and extend up the side.
Trucks experiencing this condition should be repaired by drilling a stop hole at the end of the crack, welding the crack and welding a plate over the crack
using the following procedures:
IMPORTANT:
Use filler metals from a freshly open container.
GAMW - Gas Metal Ark
Welding use:
Electrode E70S-3
SMAW - Shielded Metal Ark
Welding use:
Electrode E7018
NOTICE:
Disconnect battery (batteries) when arc welding on vehicle to avoid electronic component damage.
Service Procedure:
1.
Disconnect battery (batteries).
2.
Remove right side lower control arm. (Refer to Service Manual Sec. 3-C).
3.
Clean or grind crossmember surface to determine end of crack.
4.
Drill 1/8" stop hole at each crack end.
5.
Fill entire length of crack with weld and grind smooth.
6.
Cut a piece of 1/8" or 3/16" thick 1008 or 1010 steel using the shape as a template.
6a. Disconnect and connect brake line retainer at frame, move brake line aside.
7.
Clean crossmember to prepare for welding plate to crossmember.
8.
Using c-clamp or vise grips, clamp plate to bottom of crossmember so the arch in the plate circles the hole in the crossmember with the rear of the
plate to the rear of the vehicle.
9.
Weld plate to crossmember in the arch and the straight edge opposite the arch with 1" welds 3/4" apart.
10.
Using a torch, heat the front and rear portions of the plate and work them to conform to shape of crossmember.
11.
Weld front and rear of plate to crossmember continuing with 1" welds 3/4" apart.
NOTE:
It may be necessary to clamp front and rear of plate to crossmember to ensure tight fit when welding.
12.
Spray paint plate black.
13.
Reinstall lower control arm.
14.
Reconnect battery (batteries).
For vehicles repaired under warranty, use:
