Torque spec

[4X4HIGH]

I'm going to change out all my body mounts tonight with urethan mounts and need to know what the torque spec is for all the bolts. The instructions just say "torque to factory specs". I'm about to look in a Chiltons book but i doubt it's listed there anywhere.

 

[dyeager535]

http://coloradok5.com/forums/showthread.php?t=183015&highlight=body+mount+torque ?

 

[4X4HIGH]

Thanks Dorian. Some conflicting info in that thread but my buddy who used to do body lifts and such said 85lbs. I guess i could use the general rule for fastener size versus torque.

 

[dyeager535]

Yes, it looks like GM changed the figures a couple of times. Mine and at least one other set of figures in there are what GM spec is. No idea why 85ft-lbs is thrown out. Perhaps because rubber moves easier than poly, so 35ft-lbs is actually compressing the material, as opposed to poly?

 

[Big Blzn]

Just replaced the original mounts to Energy poly and didn't use a torque spec. Most of the bolts are 3/8" on my '72 and I tightened them several full turns past where I saw some very minor "squishing" of the mounts. I can't imagine the torque I used being more than 50ft lbs on any of them. Took the blazer on a quite difficult trail in Big Bear, Ca and the poly mounts didn't seem to shift or move at all. I would think 85ft lbs would be far to excessive for poly bushings of any type.
Hoby

 

[dyeager535]

At least on these later trucks, I suspect 85 ft-lbs may actually damage the mounting points. There are a couple of mounts that are essentially sheetmetal, and I'm pretty sure I noticed the rearmost K5 mounts bend/deform when I snugged up the bolts/nuts.

 

[Big Blzn]

At least on these later trucks, I suspect 85 ft-lbs may actually damage the mounting points. There are a couple of mounts that are essentially sheetmetal, and I'm pretty sure I noticed the rearmost K5 mounts bend/deform when I snugged up the mounts.

So true on the '72 also. Great point.

 

[thatK30guy]

I have some brand new Energy Suspension cab mounts for a '74 chassis here at home and the instruction say nothing about a specific torque number.

I do remember, way back in the early, early 90's, I bought the same cab mount bushings back then for a different project and the ES instructions at that time did mention 85 ft. lbs. torque.

Since this instruction I got in the first place, I've done all projects and customer trucks with 85 ft. lbs.
Never had any problems with this reading.

 

[4X4HIGH]

Well, it was too damn HOT today to mess with it so either tomorrow or sunday i'll tackle this project.