83 C30 rear axle alignment

[CKluttz]

1983 C30. In the process of lowering the truck, front was lowerd with drop A arms, and rear with new hangers, shackles, and removing the helper leaf spring. Ran into a problem with the rear axle alignment after everything was installed. The driver rear tire is pushed forward 1/4 inch compared to the right rear tire. We have measured it from several different refrence points... The leaf springs were removed 1 at a time, new bushings installed, and the helper spring was removed. Then reinstalled. I have checked to be sure the spring bolt is in the spring pad locating hole... I also used new U bolts. The U bolts are the correct square type that came off the truck. Only diffrence, is the orginal U bolts were flat where they sat in the top plate unlike the new which is round.. Any ideas of why the left would be shifted forward.. or is there any reason to be worried?

[Ziegelsteinfaust]

If everything was fine before. My guess would be your hangers are off.

Did you do a flip on the axle, or is it still under the springs?

A off hand possibility is the locating pin is not seated

[CKluttz]

everything bolted up fine. I didnt measure ( like I should have ) anything when i started, just started taking it apart. No on the axle flip. Yes the locating pins are seated.. i've checked that over and over

[mongocanfly]

Where are you getting your measure from?
Did you measure before you dropped?

[CKluttz]

no, i didnt measure,, i should have , just didnt. measured from center hub of frt axle to center of rear,,, from frt of rear tire to the edge of the dually fender, measured from the trans crossmember to the rear axle

[mongocanfly]

Well,,,that's not a good way to measure it...the front end alignment, or lack of, could make that much difference ...you need to find a central point to measure from, if your really concerned with it..and do triangulation measuring..
Transmission crossmember could also be off some
Unless its causing a issue , i wouldnt sweat it..

[CKluttz]

i wont get a chance to work on it again till thursday and that may be what i do.. not worry about it unless its causes a problem

[sweetk30]

Once on a alignment machine they can check axle alignments and let you know if out and if it will effect the driving . But as said if no alignment yet then measuring off front hubs it can be off .

[ky-donzi]

Some axles have spring perches that are cast and some are stamped steel. The cast ones I’ve seen have hollow voids in them that could allow you to get the axle off a little if the tie bolt that ties the springs together were to not be in the hole and in the void....maybe??

[ky-donzi]

See pic

[sweetk30]

Originally Posted by ky-donzi

Some axles have spring perches that are cast and some are stamped steel. The cast ones I’ve seen have hollow voids in them that could allow you to get the axle off a little if the tie bolt that ties the springs together were to not be in the hole and in the void....maybe??

x2 on this . . . and even egg out and cause miss alignment .

[v30crewcab]

are the alignment pins going thru the springs straight up and down? I've seen those shift and have the bottom pin back or forward on one side.