Working on Vehicles

Everyone hates it when something breaks or wears out on their car. The most common things are brakes and bearings. Well, I've never had to replace brakes because they are worn out, but I did replace them because I could.

This weekend, I replaced the rear axle on my truck. There was nothing wrong with the original one that came from the factory. It only had 109,000 miles and was 11 years old. The reason I replaced it was because it was what is known as an "open differential". What this means is that if one wheel is on ice and the other is on dry pavement, the wheel on the ice will get all the power because it has the least amount of resistance to it. This is the downfall of most differentials. The one I put in the truck came out of a stock 1995 Chevrolet K1500 truck (just so you know, it was the exact same truck as mine, just 3 years older). The difference is that this one is what is called a "locking differential". What this means is that when one wheel spins 100rpm (revolutions per minute) faster than the other, it causes a mechanism inside to engage and lock the two wheels together; giving the wheel with traction power. Had my truck been a 2-wheel-drive, this would have been more important since I wouldn't have had the extra help of 4-wheel-drive to help me. So basically now instead of having 1 wheel spinning in 2wd, I will have 2 spinning. In 4wd, instead of having 1 wheel in front and 1 wheel in back spinning, at least 3 wheels will spin at the same speed giving power to 1 or 2 wheels that actually have traction. What would have happened before the swap was all the power would have been sent to 1 front wheel and 1 back wheel that had no traction. Making me go nowhere.

After unbolting the shocks, leaf springs, brake lines, drive shaft, and disconnecting the parking brake, it was time to put in the "new" axle. It went in just fine. The only problem was that in order to hook the parking brake back up, we had to completely disassemble the drum brakes. [For future reference, drum brakes are a pain in the butt. Stick with disc brakes.] Since we had to completely disassemble them, I decided to replace all the springs (there's like 8 per drum), the wheel cylinders (when you push on the brake peddle, hydraulic fluid is pushed to the wheel cylinders which convert the fluid pressure into physical force that pushes the shoes (what brake pads are called for drum brakes) out and into contact with the drum (instead of a disc)), and the pads even though the old ones looked OK; they just need to be cleaned up. The most difficult part was connecting the parking brake back up again and getting all the springs (they may be small, but they sure are strong) hooked back to where they need to be. There are 2 pins that hold 2 of the springs to keep tension on them. Apparently the kit I bought was for multiple vehicles. It had two different length pins. We realized this quickly after the one spcing didn't come close to fitting right.

So $150 for the axle, $75 in parts, waiting 8 months, and about 10 hours of work later, it is finally in. I was so happy and excited.

I originally intended to do this earlier in the year, but I was too busy between my senior year in high school and work. A buddy and I had planned to do burnouts the last day of school. His car had a posi rear end (basically the same thing, just can't handle as much power as a locking rear end) and I was going to have the locking rear end, but I never swapped it out. So he had both wheels spinning and I was a one-wheel-wonder. Not any more suckers!

Here's a video that better explains what happens in the rear differential.