Installing Shocks on a Hummer
Updated February 15, 2012
The shocks I'm installing in this article are the Cepek adjustable units. They install exactly the same as the factory stock shocks. Remember that the factory front and rear shocks are different so make sure you get 2 fronts and 2 rears. The Cepeks are adjustable so you can put 4 of the same shocks on your truck and simply adjust the damping for the fronts and rears.
The first thing I did was to wash the underside of the truck and rinse out the lower arms by shoving a hose into the open spaces and washing out all the mud and dirt. Rinsing the A-arms out will make removing the bracket bolts easier because you hopefully won't have as much dirt get caught in the threads. You don't have to remove the tire or wheel but it makes it easier to get to. It also offers a good opportunity to check the oil in your geared hubs and rotate the tires.
I then put a 7/8" socket on the lower shock bracket bolts and proceeded to attempt to break them free. These bolts are supposed to be torqued at 178 ft lbs. I've never replaced the shocks on my 98 so removing these bolts became the challenge of the whole job.
I started on the front right. I first tried using my air impact wrench to no avail. I got one of the bolts out using a breaker bar with a 2 foot piece of pipe . Of course this was after I broke a 1/2" craftsman rachet. I then sprayed liquid wrench around the bolts. On the second one I was able to loosen it about a turn. Each time I rotated the bolt I heard a 'chink' sound. The bolt wasn't going anywhere. I was afraid I had broken the threaded portion up in the A arm.
I then used the impact in both directions to vibrate and dislodge any more dirt up in the threads. I ended up having to use an acyetlyne torch aimed up into the threaded area. Using the impact gun I was able to get the bolt out. It turned out that 2 more had to be torched. Others have used 3/4" socket sets with 8' breaker bars.
The upper shock bolts / pins came off without a problem using a 1-1/4 open end wrench and a 1-1/2" socket. Note that the bolt heads are always facing to the front of the truck. These get torqued to 300 ft lbs.
Once all the bolts are out the shock attached to the lower shock bracket just falls out. You might have to jack up the truck and compress the shock to pull it all the way out.
I cleaned up the bolts on a wire wheel and chased the threads in the A-arm with a 5/8" - 11 tap. Re-tapping the threads turned out to really help in reassembly because it cleaned out all the rust and mud from the threads.
I cleaned up the bracket and undid the nut and bolt holding the shock. I then bolted the new shock to the bracket making sure that the bolt head was facing the original direction.
When you assemble the shock to the bracket it has to be in a straight line (See the picture). Putting the whole thing back on the truck is pretty easy. Insert the shock up into the spring and start the bolts on the lower shock bracket. Line up the hole on the top of the shock using a screwdriver as a pry bar and replace the pin with the head facing the front of the truck.