pinion angle

heavy8

Well-Known Member
Can someone explain if and how the pinion angle effects weight transfer. I will be installing a new rearend soon and dont whant to do it twice. Im currently running nationals so I dont really have a baseline being that the pinion angle
now is most likley incorrect do to the nationals being a bit taller than the factory units. thanks for any help.
 

rdc

- users no longer part of the rdc family -
Your pinion angle does not affect weight transfer but it is important that it is set correctly so you wont be blowing out U-joint’s or have any vibration coming from the back. The right angle depends on a lot of different issues. It would be best to have it set by someone who really knows these things well like the guys at Drivelines Inc. in Irvine.

Shaun
 

Greg

Well-Known Member
the pinion angle should be parrallel with the output shaft of the transmission at ride height. Pinion angle dosent affect load transfer but spring mounting points do.

Greg
 

heavy8

Well-Known Member
Greg,
Thanks for the pinion angle info. Can you expand on how spring mounting points (shackle position) effect weight transfer and were longer shackels fit into the formula. thanks..
 

Greg

Well-Known Member
Ok this is kind of a controversial subject but here goes. From my personal experiances I will explain what I've learned. Everyone flips their shackels (at least ford guys) and the results are the shackle being verticle with the spring pushing at about a 45 degree angle. this makes the effort on the spring about 1.4 times the required effort compared to the shackle being at a 90 degree angle to the direction the leaf pushes/extends. I just put a National Race pack on Jens truck and it rode BAD. After lokking at it a fwe minutes i tried moving the shackle hanger rearward so the front holes were now lined-up with the rear holes (You'll have to drill two new holes, and make a new shackle to acheve full droop but you can use the stock one to try it)and wadda know, huge improvement in ride. I run my shackles like stock and had my best results having the shackle go flat at full compression. Also, dont over tighten those bolts that go through the spring, that alone makes a huge difference. As for the lenght of the shackle, I think the shortest length possible, a 62" leaf and a 14" shock wont require too long a shackle if the angle is right. but a stock length pack and a 16" shock will most likely need a longer shackle to keep from moving too much. I have never seen/ready any hard and fast rules on the subject but this what i have tried and the results ive acheved. if anyone has more info, please, let me know.

Greg
 
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