ericfx1984

added 1.5" shackles & shackle relocation boxes now rear SYE Dshaft is too long?

ideas?

I had 3" leafs and stock shackles...

still have 3" 3" leafs and above listed stuff too...

ideas?

PingPong

YOu moved your axle forward somehow.... check to see if your axle is centered. More then likely you rotated your pinion by the increase in ride height

Slick761

When you add longer shackles you angle your pinion up and move the rear end forward a tiny bit. Actually makes a big difference when you consider those 1.5 inch shackles actually moved the spring 3 inches. Thing is it probably corrected your pinion angle. If you have a cv at the transfer case and a regular u joint at the axle your pinion should be pointed straight at the output of the transfer case.

ericfx1984

so should i just unbolt the axle and move the spring pad bolt hole forward an 1"?

Slick761

No I would go to the jy and get a shorter d.s. maybe keep the other around incase you do more lift. I wouldn't re drill...

Guitrplyr423

does this mean that if adding longer shackles could possibly fix driveshaft shake and cause you to not need a sye and different driveshaft?

Slick761

.... well... ya to an extent. It worked for me before I got a longer d.s. your pinion angle will be incorrect but it works.

4.3L XJ

Not usually. For every inch you add at the end of the spring, it rotates the pinion up 1°. Usually, this causes more vibes than it can fix. The only way to fix this is by measuring angles and then making your correction with shims.

http://www.xjtalk.com/showthread.php?t=7299

ericfx1984

if it has moved forward I need to combat this... what is wrong with moving the axle back in this fashion?

Slick761

I had my pinion pointed straight at the t case and didn't have vibes... can't explain it.. guess I had some... not much. A little smoother with a longer d.s.

ericfx1984

I know my angles are out of whack though

t case fill plug is 81.5° and pinion is 87.5°

any ideas?

I have a 2° shim in there still... I could flip it around and it would lower the pinion 4° (or was it a 3°?)

4.3L XJ

As long as you get it within 5° it will be OK. Reversing the shim should do it.

ericfx1984

that would rotate the pinion down... and therefor make it further away from the t case... right?

4.3L XJ

If that is what you need. It is hard for me to really visualize with your numbers. But the bottom line is that you need to make the two angles as close as possible if you have the stock slip yoke shaft. If you have the CV joint shaft, you need to make it a straight shot from shaft to pinion.

Slick761

Ya should