[1026465]

So I'm new to YJ's and lifted 4x4's in general (dirt bike and air cooled VW guy) but I finally got a 1990 YJ with a 4.0 swapped in , the YJ I picked up has a 3.5 inch suspension lift and a tc drop. It looks like the PO just used 1.5" square tubing to drop the tc. The drive shafts don't look like they're at an extreme angle (though the rear tc pinion seal could probably stand to be replaced as it's starting to weep). I can do 80mph on the highway without any weird vibrations so I assume it's an appropriate amount of drop but I am having a few issues...

The shifter seems to bind on the boot slightly in 2nd, 4th, and Reverse, also (possibly unrelated) the reverse lights aren't coming on in reverse (maybe the shifter isn't going far enough back?). It doesn't hop out of gears or anything, but you can feel it squeezing against the boot slightly and not solidly shifting all the way to the back of the shift pattern. Is it standard procedure to just remove the boot and trim some of the tub away, or is it possible my transfer case is dropped too much?

Also the PO didn't paint the square tubing so it's getting pretty rusty, and looks like crap so I'm thinking about ditching the square tubing in favor of just a regular old tc drop kit with the derlin or metal spacers so I'm not sandwiching rusty metal up against a frame I'm trying to keep rust free. Most of the kits I see are only in 1" or 1.25" though I have found one or two 1.5" kits. I've heard from a few people that 1.5" is a bit extreme though it seems to be working for me aside from the shifter issues....should I stick with the 1.5" tc drop ?

 

[steves92]

If you can swing it get a SYE and new driveshaft, between 500-600 depending on kit and supplier. You can ditch the transfer case drop bars at that point providing the angles are good. I went with the super short, that allows for a longer driveshaft and less severe angles at the driveshaft connecting to rear axle, I got the double cardan style. With your shifter, mine did the same....there is a metal plate thingy under your shifter boot(which also is reinforced I believe) that you can remove. Reinstall the boot and problem SHOULD go away- mine did.

 

[1026465]

An SYE and drives shaft aren't in the budget right now, but I will definitely check out under the boot and see if I can't get some more clearance.

As far as the reverse lights go do they come on when the shifter is at it's rear-most in the shift gate or just as you start going into reverse? I'm able to use reverse just fine but the lights dont' come on, the bulbs are good and the switch is hooked up....though there is another length of wires with a plug dangling back behind the transfer case and I can't seem to figure out where it goes, the transmission is the original 1990 AX-15 with the cable driven speedometer.

I thought it might be the speed sensor wire for the later electronically driven speedometers since the engine has been swapped to a 4.0 and has the 1992 computer but the PO specifically said the only non 1990 wire that goes past the bulkhead is the one for the fuel pump so the transmission bundle should be original. I haven't crawled under there with the voltmeter to test the switch yet because of all the snow but with the shifter barely making it into reverse I figured it might be the reason for the reverse lights not coming on.

 

[1026465]

Hmm, I checked with the PO and he doesn't remember if the harness to the transmission was changed when he did the engine swap. On a 1990 AX-15 with a cable driven speedometer how many switches are there supposed to be on the transmission/transfer case, just the reverse light switch on the passenger side and maybe a neutral safety switch near the shifter right?

 

[Luckymac]

I did a body lift and ran into a similar issue with the shifter.
With both boots off and the metal ring for the top boot screwed in place, I used a die grinder to grind away just enough of the floor pan and retaining ring to allow the shifter to fully engage all gears (2,4, & rev). It was close but I was able to keep enough of the retaining ring to not cut all the way through the complete ring.
I replaced the upper boot, leaving the inner, or lower boot, off.
Once I had it all together I found the rubber of the boot held the shifter out of reverse just enough that I had to hold the shifter in reverse to keep it from popping out of gear. I could have cut a little more floor and ring away but opted to hold the shifter in reverse.
Eventually I will redesign or make a new ring that will allow the shifter to stay in reverse without holding it there. I may heat and slightly bend the shifter if that looks easier.
Hope this helps. Good Luck, L.M.

 

[1026465]

I'll definitely check that out when I've got some time to work on the Jeep. It looks like the PO must have used the trans harness from the 92 because if the wiring diagrams are right then the reverse switch is the only thing on the trans/tc that gets electricity on cable speedo AX-15's, which means the un-used hanging connection must be for the later style digital speedometer sensor.

What height TC drop do most people run with a 3.5 inch lift? I hear some of the 3.5" lift kits actually come with 1.5" tc drops.

 

[chestercospin]

Changing the trans fluid did wonders to my sticky shifter. Just a thought but probably won't impact all your describing.

 

[1026465]

Well I finally got around to removing the shifter boot, the second rubber boot under the main one was the culprit. The shifter wasn't actually hitting the tub but it was bunching the lower boot up between the shifter and tub, I removed the lower boot and now I can get into all gears just fine.

I still have no reverse lights though, and since they're on the same fuse as the turn signals and those work I'm thinking the switch is bad, I'm going to crawl under there and test it at the switch sometime soon.