Final Torque Upper & Lower Control Arms.....'splain' this to me?

[flintknapper]

Getting ready to reinstall my control arms and the FSM says to let the suspension 'settle' before applying the final torque figure. I'm guessing this means the 'Vehicle's Weight' needs to be on the suspension first? And why is this important?

Thank You,

Flint

 

[TheForger]

I’ve always been told to have the truck on it’s own weight when torquing any control arms bolts. If it’s free hanging the bushings will compress outside of their normal operating range, then when the truck is let down it can stretch them beyond their limits and tear them. It essentially locks the bushing into a pre-stressed position.

 

[flintknapper]

I’ve always been told to have the truck on it’s own weight when torquing any control arms bolts. If it’s free hanging the bushings will compress outside of their normal operating range, then when the truck is let down it can stretch them beyond their limits and tear them. It essentially locks the bushing into a pre-stressed position.

So...do I need to drive it around a bit (slowly at the house) then jack the front end up from underneath each lower control arm, put on jackstands (tires removed for better access) or something else?

 

[katit]

With AHC I would make sure you start truck and operate AHC and then set it in N and then torque those control arms.
Goal is to have rubber bushings in free (not stress) position when at normal riding height

 

[katit]

So...do I need to drive it around a bit (slowly at the house) then jack the front end up from underneath each lower control arm, put on jackstands (tires removed for better access) or something else?

Whatever works for you. On some cars I was measuring distance from fender to center of hub, then remove wheel, just up under lower arm to compress to needed position and then tighten. On other cars if you can just lower car with wheels on blocks and access this way.

With LX I don't know, maybe you can just do it when car parked.

 

[JunkCrzr89]

So...do I need to drive it around a bit (slowly at the house) then jack the front end up from underneath each lower control arm, put on jackstands (tires removed for better access) or something else?

No. Install control arms and their bolts + nuts finger tight, but install the torsion bar torque arms and torque their bolts + nuts to spec (166 ft-lbf). Put wheels etc. back on and drop the truck off jack + jack stands so that truck is 100% on its own weight. Make sure the alignment cams are at your match marks and then torque all the control arm bolts/nuts to spec (72 ft-lbf for uppers and 170 ft-lbf for lowers).

Helps if yer skinny

 

[flintknapper]

No. Install control arms and their bolts + nuts finger tight, but install the torsion bar torque arms and torque their bolts + nuts to spec (166 ft-lbf). Put wheels etc. back on and drop the truck off jack + jack stands so that truck is 100% on its own weight. Make sure the alignment cams are at your match marks and then torque all the control arm bolts/nuts to spec (72 ft-lbf for uppers and 170 ft-lbf for lowers).

Helps if yer skinny

^^^^^^


Yeah, well that's going to be a problem then.

6'-5" and 245 lbs. (down from 270)

Going to be a few years before I am anything remotely close to 'skinny'.

 

[JunkCrzr89]

^^^^^^


Yeah, well that's going to be a problem then.

6'-5" and 245 lbs. (down from 270)

Going to be a few years before I am anything remotely close to 'skinny'.

You have long arms tho, so should be able to reach!

 

[suprarx7nut]

The reason for this, as I understand, is to let the bushings rest as close to "normal" as possible. As the control arm moves up and down, the bushing's rubber twists. If you torque the bushing with the arm high or low, the bushing is going to be twisted during normal driving or resting. That's going to wear the hell out of that bushing. You want the bushing to be as close to "normal" as often as possible. That means torque it when the arm is at its normal resting position (IE parked or on smooth road).

 

[flintknapper]

You have long arms tho, so should be able to reach!

View attachment 2457074

Haha, 'Touche'. Made me laugh.

Yes, long arms.

 

[Beto Cruiser]

Not sure if others struggled like I did but I couldn't access the UCA/LCA bolts to torque with the car put back together (TBs and wheels on). I needed to remove the wheels to torque the UCAs (my torque wrench had too much play for the limited room available) and I needed to re-loosen/pry the TBs to fit a wrench over the bolts on the LCAs so that they would stop spinning when I tried to torque. Total PITA, but a fitting way to end a frustrating job!

 

[flintknapper]

Not sure if others struggled like I did but I couldn't access the UCA/LCA bolts to torque with the car put back together (TBs and wheels on). I needed to remove the wheels to torque the UCAs (my torque wrench had too much play for the limited room available) and I needed to re-loosen/pry the TBs to fit a wrench over the bolts on the LCAs so that they would stop spinning when I tried to torque. Total PITA, but a fitting way to end a frustrating job!

^^^^

That's probably what I will do. Assemble it all, drive it around the pasture a bit (slowly), check my heights (AHC), jack up each lower control arm and support, remove wheels and do final torque. Then take it someplace for an alignment.