You may have difficulty with the multiplier, it may just start moving the truck around, basically jacking it up rather than applying torque to the bolt. If you can put it on a lift, that should be better. Or if you can get the multiplier to brace against the frame or something solid on the truck.

If someone wants a lower cost path to a big torque wrench, there is a Neiko electronic torque adapter that covers the 400 range, something like $70. Add a 3/4 breaker bar for about the same and you have a wrench for 1/3 the cost of an actual 3/4 drive 250-750lbft tool. (or whatever exact numbers they offer) Oh, and get the long 27mm and 30mm sockets regardless, the bolts and nuts are big.

I used an older Milwaukee 1/2 drive impact rated to 450lbft. It seems to be at the right tightness. It's been months and many thousand miles, no clunking or falling apart. And I had torqued it to about 300 with hand tools, and got a fair amount more with the impact. I think this one is probably putting out to its rating.

 

hmm... I'll have to think about this. I thought loosening the bolt would apply downward pressure so I wasn't thinking of the truck lifting. My plan for retightening was set my torque wrench for 250 ft/lbs it's max, then mark the bolt at the top, then get another 1/4 turn at least with my breaker bar. But I do like that electronic torque adapter you suggested. Maybe just that and buy myself a 40" 3/4 drive breaker bar. I've got 4 months of snow left to think about it.

 

I only used the multiplier for tightening. One of my bolts was not rusted, impact took it right off. Other one was rusted in the bushing, that was many applications of PBB, nothing (that I had access to) was removing that before eating out some of the rust.

For reference, when tightening I had the wheels back on. You should have the truck on its wheels for torquing, or at least have the wheels jacked up separately to get the angles right before putting the serious torque on the bolts. Being on its wheels, the leverage off the jack stand just bounced the truck. Apparently trying to apply 400lbft to a 30mm nut is enough power to pick up the body at the front end, at least a couple inches.

 

I used a ratchet strap hooked on one end, spaced evenly around the circumference then hooked the other end and slowly ratcheted until it was compressed. This was on my ranger and a smaller spring than the f150.

 

When I changed the passenger upper control arm last spring, I measured up from the middle of the hub to the bottom of the fender while the truck was sitting on the ground, I think it was 24.5". Then before I torqued the upper control arm bolts I jacked up the lower control arm until the center of the hub was 24.5" from the fender again. That was my plan for the the shocks.

 

My Eastwood spring compressor arrived last night. It was worth waiting for! Truck has four new Bilstein 4600 shocks installed. Original rear shocks had some life in them but the fronts were DEAD. What a difference in ride and handling, wish I’d done this job a year ago!