So I installed a coil spacer lift. After doing so im having noise in the front end going over bumps. When I installed the new front struts (factory), i noticed that the front diff assembly was wiggly and I could move it side to side. Could this be my noise issue? What is usually taking up the slack in that assembly?

Yea very well can be. Did you tighten you swaybar and you tie rod end back up? Your axle come out(4x4) equip.
what model tracker is it?

Just look over the bases and trace your steps and hopefully you will solve ur problem

its a 97 sidekick 4 door 1.6l 5 speed.
The sway bar was disconnected but is back togeather. The right axle did come out to install the struts. Ill check to make sure it has not poped back out.

Did you put a set of strut spacers on along with the spacer lift?

Yea I left that out. Ur struts could be fully extended.could be riding.like crap. If not u might wanna find a set it some longer struts like OME from rocky-road

I built 2." strut spacers to match the coil lift.

Im gonna say u made 2" rear and 2"front spacers? If so you need to take the front down a inch. I installed a 2" spacer kit last week on my tracker and the front coil and strut is 1.5" and rear is 2" and have no sounds. You CV's could be the problem.

2.5" coil spacers on rear. 2" coil spacer front. 2.5" strut spacer front. 2.5" total lift. There is tons of travel in the strut still. The cvs are not the issue cause they are not even engaged. This is just street driving. stutter bumps

Did you set the coil springs were the very end of the coil is touching the metal. Kinda hard to explain. Its on the bottom.

Yeah, the springs are set in the notches in the bottom.

You say the diff is wiggling around..Sounds like you need to put her in the air and have a good looksee. Sounds like your diff mounts are failing/loose/broke.

Im bringing it into the shop at school next week, so Ill check her over good then.

You are right at the limit for your front end, anything over a 1.5" front spacer tends to cause the CV's to fail when off-roading.  So be a bit careful your first few times out when climbing hills.  Let us know what you find out when you crawl under it.

Well we are going on a bit of an expedition this weekend. Still plenty of snow here so I dont know how much we will be able to do, but ill keep you posted.