2005 Avalanche Frame, Fuel, and Rear Diff rebuild
A friend of mine mistakenly bought this Avalanche 2500. He knew there was a little frame rot and asked me to fix it. This truck was quickly named Pandora, everything I touched turned into another project. It occupied my driveway for 6 months getting it all fixed. There aren't many parts available for these vehicles anymore so I had to modify or flat out fabricate many items. Specifically the frame parts. The good news is, he has been using the truck regularly for the last 2 years since the rebuild. Here is a brief overview of what was fixed.
Step 1
One would think this might be the easiest part of the job but it turned out to be the most time consuming. Once I discovered the bad pinion bearing I took the rear cover off to discover a slurry of metallic oil. It took a full case of brake clean, 2 gallons of diesel fuel, A full bottle of WD-40 Specialist Degreaser, and a couple weeks of scrubbing the housing out before it came clean enough to put new bearings in. Luckily he hadn't damaged the gear set so I was able to get a bearing kit, press off the pinion bearings, replace the races, and reassemble the rear end.
Step 2
I didn't get many photos of replacing the fuel system but it got two new fuel pumps, all new fuel lines (shockingly available), and a new fuel neck. The fuel neck however was not available for the 3/4 ton Avalanche so I had to take a regular one and modify it to work in the application. I started by cutting the "new" neck to a shorter length then added two step down pipes to make it fit the inlet hose for the tank. After welding those together, I heated the pipes and slowly bent them into a "J" shape to reach the fuel inlet hose. Lastly I bead rolled the end so the hose wouldn't fall off the pipe. I had to remove all of the front suspension to route the new fuel lines and filter up to the engine. Every fuel line crumbled as I touched it causing leaks everywhere.
Step 3
As with the fuel system, I had to make new parts for the frame. There are frame patch kits available for most applications but not this rare bird. So new frame ends were drawn up with CAD (cardboard aided drafting) then cut out with my torches, heated with my torches and bent into the correct shape. Next the body mounts needed to be fabricated. Again with the CAD then to the real CAD (computer aided drafting) so I could cut the parts out on the plasma table at work. Once I had my parts I then welded them together and attached them to the frame. I had some frame bushings left over from another project so I recycled those into this one.
