Cab rear suspension

As part of 'going through' the truck I replaced the rear cab shocks and air bags. The shocks looked original and the air bags had a lot of checking. Here is what I used:

Horizontal shocks - Gabriel 83029
Vertical shocks - Gabriel 83028
Air bags P/N 21165207
Leveling valve P/N 20470002
Prior to removing anything I aired up the truck and measured the space between the cab and frame. 9.25 inches. While it was aired up I stacked a 6x6 and a 2x4 between the frame and the cab supports. This will support the cab when the air bags are emptied. Also, unlatch the hood.

The whole process is remove and replace. The shock bolts use 18mm and 21mm sockets. Seven of the eight bolts came out easily, but there is always that one bolt that is frozen in the shock mount. I spent a couple hours cutting it out using a combination of an air cutoff wheel and a sawzall, part of which required crawling under the truck and contorting myself around a crossmember and the 6x6 cab support. The sound of the shock falling free was wonderful.

I had an issue with the bottom bolt on the driver's side vertical shock. There is a bracket that cradles the trailer wiring cable as it crosses the frame. The bracket would not let the bolt come all the way out. The bracket is huck-bolted so this reinforced my belief the shocks had never been changed. I had to cut the bracket to get the bolt out.

I definitely needed new shocks.

The air bags were another treat. They screw into a welded nut inside the cab support channel. I had started soaking the nuts with Kroil oil a few days prior. Nevertheless, the bags wouldn't turn freely. Using a pipe wrench with a breaker bar I was able to get the passenger bag to come loose. I ran a tap through the threads to clean them out.

I wasn't so lucky on the driver's side. The welded nut was no longer welded and spun with the bag. I used a sawzall to cut the mounting bolt. I opened up the hole in the cab channel to allow me to push an M10x1.5 nut inside to screw the new airbag into.

I ran new air lines to the bags and protected them with 5/16" hose.

The finished project. One more thing to cross off my list. I've had these parts setting around since Fall 2016. It was nice to get it done.

Update November 2021 - I replaced the horizontal shocks with a cab torque rod setup.

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