correct rear shackle angle?

[Masher]

What's the correct rear shackle angle? I just swapped to a van-width 14bolt and new 10" rear springs. I had 6" springs and 3" blocks before. It is on a 1996 SFA GMC. I've got a shackle flip and 6" shackles and with the old setup the shackle angled to rear of the truck at about 45 degrees. Now it actually angles forward at about a 45 degree angle. Should I drill new holes and move the rear shackle hanger forward so I can get the shackle to angle to rear of the truck?? Also will new springs settle in a bit??

 

[YZEATER]

it needs to be angled back to about 45 degree's. your new springs will settle a tiny bit, but them being 10" lift, not much to notice i bet. move the mounts forward, clamp them in place, and set the weight of the truck on them to check the angle before you drill new holes.

 

[ChrisPerry]

What's the correct rear shackle angle? I just swapped to a van-width 14bolt and new 10" rear springs. I had 6" springs and 3" blocks before. It is on a 1996 SFA GMC. I've got a shackle flip and 6" shackles and with the old setup the shackle angled to rear of the truck at about 45 degrees. Now it actually angles forward at about a 45 degree angle. Should I drill new holes and move the rear shackle hanger forward so I can get the shackle to angle to rear of the truck?? Also will new springs settle in a bit??

If you used the shackle flip from ORD or one like it you may have put the brackets on the wrong sides. Most of the brackets have an offset built in to give a good shackle angle.

 

[tRustyK5]

Good shackle angle is dependant on the amount of arch the springs have too. There is no generic perfect angle.

A perfect angle for your springs should be determined by allowing the springs to fully droop and ensuring the shackle does not come too far forward. If the shackle can be pulled too far forward at full droop it can invert. I'd say at full droop the shackle should be only slightly past vertical the wrong way. Say 80 degrees.

For good angle the other way you can measure from the front hanger bolt and get a really good idea of what the max angle will be. a 52" rear spring is 52" when dead flat. If your shackle ends up at 30 to 40 degrees past vertical when the spring is flat it'll work just fine.

Shackle length is another variable that needs to be factored in. If your springs are longer and flexier than stock you need longer shackles as the min/max of the springs will move a shorter shackle further than what it's capable of without having a problem with inversion at full stuff or full droop.

Rene

 

[Mott Welding Inc]

Just read you post on pirate, **** I hate that site everyone just telling you what to do or what you should change your truck too! There no need ever for a 10" lift, these clowns never came
To northern Canada I guess haha