Torque Confusion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

wpavlis · 02-01-2018, 04:58 PM

So I recently replaced the rear control arms, springs, and shocks on my 68 c10. I am confused about what torque settings to use. I have a FSM. In the instructions for control arm replacement it says the U-bolts should be torqued to 200 Ft-lbs. In the back of the manual the in the torque spec chart it shows 215 ft-lbs. I do have auxiliary springs, and under that section the instructions show yet a different value of 270 ft-lbs. I currently have them torqued to 200 as that is as far as my torque wrench goes. Do I need to find/borrow one that goes to 270? I have found other instances of this. I almost ruined one of my shocks as the instructions say to use 135 ft-lbs, but in the back it says 75 which I believe is accurate.

On the note of torques, I plan on pulling the aux springs off next to paint them. The manual shows a whopping 370 ft-lbs for the single mounting bolt. The factory used a castle nut with a cotter pin. If I even had a torque wrench capable of the 370 ft-lbs, my gut tells me the bolt would not hold that. What have others done? Thanks,

Bill

harpo231 · 02-01-2018, 05:13 PM

you will find aux springs take much more torque

harpo231 · 02-01-2018, 05:16 PM

http://67-72chevytrucks.com/vboard/a...1&d=1517519785

wpavlis · 02-01-2018, 05:22 PM

Ha! That has even more different specs! I think the 270 must be correct for the u bolt. What about the auxiliary spring mounting bolt? Is 370 correct?

harpo231 · 02-01-2018, 05:29 PM

I have only the document I posted so I would say yes.. you can wait for the know it alls ,but may end up with more specs !!

RichardJ · 02-01-2018, 08:21 PM

After you decide on the specs, Make an extender for your torque wrench. I used a piece of 2" Channel iron and a Craftsmen breaker bar that already had the hole and flat sides. A U-joint strap holds it solidly in the Channel. The 1/2" square hole was drilled, then filed by hand.
A little math and you can use your torque wrench for just about anything. I have used this setup many times to do those front wheel drive and cartridge type axle nuts that sometimes call for 300 + ft-lbs

This was in Hot Rod Mag back in '84. I made this bar up and have used it many times over the years with my beam type torque wrench.

mike16 · 02-01-2018, 11:13 PM

bravo Richard. You beat me to it. the math bits a a little scarry but if in doubt there are SAE torque specs for hardware and its a range rather than a specific value.

02-01-2018, 04:58 PM	#1
wpavlis Registered User Join Date: Oct 2015 Location: San Tan Valley, Arizona Posts: 313	Torque Confusion So I recently replaced the rear control arms, springs, and shocks on my 68 c10. I am confused about what torque settings to use. I have a FSM. In the instructions for control arm replacement it says the U-bolts should be torqued to 200 Ft-lbs. In the back of the manual the in the torque spec chart it shows 215 ft-lbs. I do have auxiliary springs, and under that section the instructions show yet a different value of 270 ft-lbs. I currently have them torqued to 200 as that is as far as my torque wrench goes. Do I need to find/borrow one that goes to 270? I have found other instances of this. I almost ruined one of my shocks as the instructions say to use 135 ft-lbs, but in the back it says 75 which I believe is accurate. On the note of torques, I plan on pulling the aux springs off next to paint them. The manual shows a whopping 370 ft-lbs for the single mounting bolt. The factory used a castle nut with a cotter pin. If I even had a torque wrench capable of the 370 ft-lbs, my gut tells me the bolt would not hold that. What have others done? Thanks, Bill

02-01-2018, 05:13 PM	#2
harpo231 Registered User Join Date: Nov 2014 Location: Lincoln City DE Posts: 1,292	Re: Torque Confusion you will find aux springs take much more torque __________________ Stan 67 swb BLU MULE posted via flip-fone

02-01-2018, 05:22 PM	#4
wpavlis Registered User Join Date: Oct 2015 Location: San Tan Valley, Arizona Posts: 313	Re: Torque Confusion Ha! That has even more different specs! I think the 270 must be correct for the u bolt. What about the auxiliary spring mounting bolt? Is 370 correct?

02-01-2018, 05:29 PM	#5
harpo231 Registered User Join Date: Nov 2014 Location: Lincoln City DE Posts: 1,292	Re: Torque Confusion I have only the document I posted so I would say yes.. you can wait for the know it alls ,but may end up with more specs !! __________________ Stan 67 swb BLU MULE posted via flip-fone

02-01-2018, 08:21 PM	#6
RichardJ Registered User Join Date: Apr 2010 Location: So Cal Posts: 1,470	Re: Torque Confusion After you decide on the specs, Make an extender for your torque wrench. I used a piece of 2" Channel iron and a Craftsmen breaker bar that already had the hole and flat sides. A U-joint strap holds it solidly in the Channel. The 1/2" square hole was drilled, then filed by hand. A little math and you can use your torque wrench for just about anything. I have used this setup many times to do those front wheel drive and cartridge type axle nuts that sometimes call for 300 + ft-lbs This was in Hot Rod Mag back in '84. I made this bar up and have used it many times over the years with my beam type torque wrench. Attached Images __________________ '67 GMC 2500, 292, 4spd, AC

02-01-2018, 11:13 PM	#7
mike16 Registered User Join Date: Dec 2009 Location: bisbee, arizona Posts: 1,530	Re: Torque Confusion bravo Richard. You beat me to it. the math bits a a little scarry but if in doubt there are SAE torque specs for hardware and its a range rather than a specific value.



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