Core support/cab sequence

[howzzzit]

Is there a specific sequence I should follow when tightening new core support and cab bushings? Torque core support first? I am doing one side of the cab at a time, but have replaced both core support bushings. Hope to not have alignment problems. Thanks.

[Richard]

My process is (will be) loosely mount cab and bed, line up shim and tighten. Loosely mount core support and mount/line up fenders. Maybe snug core support a bit but wait until hood is mounted until final tightening as core support may need to rack right or left. All may require adjustment. No worries as it all can be loosened and adjusted. Will take some time and patience.

[71CHEVYSHORTBED402]

I installed the cab first, in sequences to a under the lowest suggested torque setting, using rubber mounts. Setting the cab was easy in my case, because the 4/2.5 drop levels the truck. Then I installed the core support to a low torque setting with a level. The initial torque, and final torque settings are the same or very close, LH & RH sides.

Then we installed the doors and fenders and hood.

Once everything looks great torque the cushions a pinch more to a reasonable setting.

I finished at the lowest or a pinch more the suggested torque setting, for the cab. And less than the suggested setting at the core support, which finished at 30 ft. lbs.-ish.

Kits vary, same would apply for torque requirements - keep an eye on the cushions and their washer plates as you go.

[howzzzit]

Thanks, Tony. I'll check the support level and shim as necessary. My cab and fenders are factory installed. So far I have just replaced the driver side cab bushings and radiator support bushings. If I torque the support to 33 lbs and snug the cab not even to torque guidelines both doors are off. The strike hits. I will check the level on the support first. By the way, I did shim the rear cab bushing to bring up the door line to match the bed line. I put the original large shim back on the front cab bushing. Maybe need to add a shim, but the line is on with the fender. I noticed the cab support mounts from Classic industries aren't as thick as the originals.

Thanks again with any suggestions

[71CHEVYSHORTBED402]

Originally Posted by howzzzit

Thanks, Tony. I'll check the support level and shim as necessary. My cab and fenders are factory installed. So far I have just replaced the driver side cab bushings and radiator support bushings. If I torque the support to 33 lbs and snug the cab not even to torque guidelines both doors are off. The strike hits. I will check the level on the support first. By the way, I did shim the rear cab bushing to bring up the door line to match the bed line. I put the original large shim back on the front cab bushing. Maybe need to add a shim, but the line is on with the fender. I noticed the cab support mounts from Classic industries aren't as thick as the originals.

Thanks again with any suggestions

IMO, you should replace the RH side and then torque the cab in sequences, starting at the rear. When the cab's set perhaps you'll need to adjust the strikers, maybe a shim more or less. Your door perimeter gap should be approx. 3/16"

I was able to reinstall the original cab shims for a nice stance. One each, they're 1/8" thick.


Notes I took using cushions from ClassicHeartbeat.

Per various sources the support’s rubber cushions are torqued 35-55 foot lbs. Those on this rebuild were torqued by eye and feel to no more than 35 lbs.

Per various sources including the assembly manual, the front cushions are torqued to 70-90 foot lbs., and the rear cushions are torqued to 35-55 foot lbs. The front cab cushions were torqued to 78 foot lbs., and the rear cushions torqued to 38 foot lbs. for this rebuild.

[howzzzit]

My core support is dead level with core support and driver side mounts loose. Guess I should tighten them down enough so everything is just secured and then change the passenger side? Then fine tune. Sound like a plan?

[71CHEVYSHORTBED402]

Originally Posted by howzzzit

My core support is dead level with core support and driver side mounts loose. Guess I should tighten them down enough so everything is just secured and then change the passenger side? Then fine tune. Sound like a plan?

IMO tighten nuts in sequences for the entire assembly as a unit, from the rear forward. Leave enough nut so things don't slip while you position the RH cushions.

[jumpsoffrock]

I really wish someone from the factory could tell me how they did it 100 times per day. The original lines on my undisturbed rust '72 are really good.