My 2000 3/4 ton chevolet pickup, 100K miles, is sagging in the front, especially on the driver's side. I've adjusted the torsion bar preload as much as possible, but the suspension is still resting on the jounce bumpers. I have the tool needed to remove the torsion bars. Is it safe to remove the preload bracket and turn it an extra 60 degrees to get more preload? There wasn't much adjustment available when the truck was new. If not, replacemnt bars are about $200-$250 each, should I put new stock bars back or try to find some a little stronger? My truck has not been lifted and does not have a winch, but it does has a brush guard weighing about 80 pounds. Any suggestions welcome.

I wouldn't try to re-clock the brackets, that's just going to overstress the already stressed and stretched torsion bars. Ever see one break? Not a pretty site or a fun ride. Be safe and replace the bars, it's not hard to do and it will give you peace of mind!

In doing more research it appears the 2500 model in 2000 has different torsion bars than the 2500s (not HD) in 2001-2005. Also there are different bars available for the trucks depending on the options, e.g. snow plow, off road, etc. Also there seems to be torque arms (some times called keys) with different indexes (and different color) both from GM and aftermarket. Anyone know where to find information that makes sense of it all? I don't mind replacing the bars if necessary, but I want to make sure I buy the right ones.

You might try over at gm-trucks.com

I found some good information at http://www.dieselplace.com/forum/archive/index.php?f-76.html

also at http://www.fullsizechevy.com/forums/showthread.php?t=65871 This post gives the part numers and ratings for GM torsion bars. My 2000 2500K has GK bars and my new Duramax 2500HD has the GL bars.

There is a long discussion in another thread at www.fullsizechvey.com about adjusting and re-indexing torsion bars. After thinking about it, I believe they are basically the same thing and neither significantly changes the load on the torsion bar because the weight on the bar doesn't change.

Anyway, the left bar on my older truck has been near the limit of its adjustment since the truck was new and the "Z" hieght is near minimum. I believe this has caused extra load on the "jounce bummper" or "bump stop" on the left side. I've had to replace it three times. So I'm going to try a "green key" on that side to hopefully lift it a little more. Seems like the jounce bumper shouldn't be making contact when the truck is stationary to allow upward wheel movement when you hit a raised bump. But you shouldn't set the Z height too high or you'll top out the shock. BTW - A new key (torque arm) is about $25 and a new torsion bar is around $250.