Lift shackles aren't safe

macgyverFJ62 · 11-28-04, 12:56 PM

I heard that lift shackles alone put extra stress on springs and other parts, are longer than stock shackles okay or what? what are your guy's thoughts on that?

woody · 11-28-04, 01:15 PM

2" overstock is generally recognized as ok, any longer tends to have major effects on steering, axle caster, driveshaft vibrations, and other drivetrain parts....I would NOT recommended more than 2" longer for on-road.

Rear axle effects are minimal, front is where most issues occur.

DocB · 11-28-04, 05:51 PM

I second the above. I run like 1 inch longer on front and 2 in longer in rear. Remember you only get half the extra length in lift due to shackle angle somewheres around 45 degrees. So at the most with (safe) lift shackles you will only get one inch of lift.

cahilc · 11-28-04, 05:56 PM

Quote:

Originally Posted by macgyverFJ62

...
I heard that lift shackles alone put extra stress on springs and other parts ...

Adding to the above posted advise ...

There's also some sort of esoterical shackel lenght to spring relationship where if a shackle is to long it will allow the spring to over stretch during compression, thus shortening the springs useful life.

Realistic ??? Theoretical, definitely.

I've run into this a couple of times but definitely do not understand the details.

Cheers,
Cahil

macgyverFJ62 · 11-28-04, 07:03 PM

thanks I'll take that into consideration when I get my shackles

DocB · 11-28-04, 08:29 PM

A longer shackle puts more leverage on the leaf spring when flexing; it's a longer lever. Therefore, springs may sag quicker. Search for my re arch/add a leaf thread. I ended up spending $$ but my ride is sweet and I got around 2 inches of lift. With just a shackle lift and not too saggy springs, you should be able to run 32s. 33s will fit mine on the street but rub at full turn/flex.

macgyverFJ62 · 11-28-04, 09:27 PM

DocB you inspired me My plan is to get the long and short leaf from man-a-fre and put both in each spring pack and get them re-arch I'm hoping to get 2-3 inches of lift with this and some longer shackles

devo · 11-28-04, 09:33 PM

Remember, that when you re-arch the spring will shorten and add-a-leafs will make it stiffer.
What kind of ride are you after? Sounds like a stiff lift to me?
devo

DocB · 11-28-04, 10:04 PM

My ride turned out real well, but I think the max lift you can get with re arch, added leaves is about 2 inches. Run longer shackles and a stouter leaf in the rear, as it tends to ride low/sag sooner. Goal is to have the shackle angle just shy of upright, about 5 to 10 degrees off. True, the better lift kits have longer main leaves and therefore shackle angles of like 45 degrees and therefore (theoretically?) a better ride, but with a re arch you are limited by stock main spring length. My ride turned out great, though.