Would a vacuum leak, or lack of vacuum cause an issue with the transmission shifting properly (specifically into OD)? Having some odd shifting issues and I moved the vacuum egg around and was wondering if this was the cause or not.

 

Negative. AW4 is electronically controlled and has a throttle valve cable. No vacuum fittings.

 

What are the shifting issues?

 

Originally, it just seemed like it would come in and out of lockup on the torque converter alot, on the highway. Stock 3.55 gears and 31's.

But, recently, it acted like it was a cold automatic tranny for about the first 30 seconds of driving it (cold). You know, where it acts like it doesn't want to go then it jerks forward. After that, I noticed that the one time I drove it, it acted like it was in "3" on the highway. I played kick down a few times, and after a while of that it finally shifted into OD, but it just didn't act right. I only bought this two months ago, but I'm going to change the fluid/filter as I do not know when it was changed last (but I do know that it has plenty of fluid in it).

 

Change the fluid. Use the drain plug and drain it. Refill is about 3.75 quarts.
Do this, too:
https://www.cherokeeforum.com/f2/free-quick-fix-41821/

 

Haven't tackled fluid yet, but that is next. I did the quick fix, and oddly enough, barely ANY conduit came out after I snapped the throttle back from WOT, yet I know I pushed almost 2 inches (that's what she said) back in there.

Going to take it for a little test drive , next.

 

Try this, too.

Cruiser’s Trans Plug Refreshing

Over near the trans dipstick tube are 2 rather large connectors. One is black and the other gray. These 2 connectors carry all the info between TPS, TCU, NSS, speed sensor, and trans solenoids.
Unplug each one, visually inspect for corrosion or bent pins, spray them out with electrical contact cleaner and plug them back in.
Revised 3-28-2012