CAD Bypass question on a 90

The 4wd stopped working on my 90 Cherokee (231 TCase). I came across some folks recommending a bypass as described in this thread:
http://www.cherokeeforum.com/f51/fre...ss-91-a-38629/

So I decided to try that. However, rather than pull the C clip and move the fork over, I simply turned the housing around upside down and the fork met the locking ring in the locked position perfectly. I plan to leave the vacuum lines disconnected. I gave it a quick try in the gravel and sure enough the 4WD works as it should.

The one difference I notice is that the 4WD handle is much harder to engage and disengage. Is that normal after this procedure? Can the we still shift on the fly like we used to or is it better to stop first?

Anybody have any experience with that?

Its a 231.. You should be stopping to shift into 4H and 4L anyways as well as co
Ing back out into 2wd. Locking that collar in the axle has no effect on how the handle shifts the transfer case into 4wd.

And you will want to atleast plug the vacuum lines that use to go to the axle for the collar actuator. Otherwise you may have a vacuum leak that can cause other drivability issues not related to the 4wd set up.

magimerlin said:

Its a 231.. You should be stopping to shift into 4H and 4L anyways as well as co
Ing back out into 2wd. Locking that collar in the axle has no effect on how the handle shifts the transfer case into 4wd.

Click to expand...

why is it the 231 claims its on the fly shifting up to 55mph? idk i keep my shifting speeds below 5 mph before i engage 4 hi or 4 low and i do shift into neutral for 4 low but the rolling for me helps it slide into gear easier

let me know how locking the collar works for you, last run i did my vac lines collapsed and only partially engaged my front axle causing a grinding noise under a load, since ive switched hoses no more grinding so far but the whole vac line thing is pretty irritating

Here's the truth:

Here's how the factory suggests you shift the transfer case and I've been doing this since these things were new and I worked at the dealership. Quoted from the owner's manual.

"To engage, shift the transfer case lever from 2H to 4H while the vehicle is moving at any legal speed". I let off the gas, throw the lever and then tap the gas and let off.

4L position: " To engage, slow the vehicle to 2-3 MPH , shift the transmission to Neutral, then shift the transfer lever to the right and pull firmly rearward to 4L".

Shifting into 4H should be seamless at speed (my personal limit is about 35). But as Cruiser says, 4L is a different story.

I still don't think I'd be going 55 if I thought I needed 4x, even 4H.

All kinds of accidents on Donner Pass going over the Sierras because of the nimrods with Jimmys and Explorers thinking they're immune to the laws of physics because the rig has four wheel drive. People that never drive on snowy roads end up upside down because they still go 60+ on a snowy, icy road..."hey, I got four wheel drive"!!

cruiser54 said:

Here's the truth:

Here's how the factory suggests you shift the transfer case and I've been doing this since these things were new and I worked at the dealership. Quoted from the owner's manual.

"To engage, shift the transfer case lever from 2H to 4H while the vehicle is moving at any legal speed". I let off the gas, throw the lever and then tap the gas and let off.

4L position: " To engage, slow the vehicle to 2-3 MPH , shift the transmission to Neutral, then shift the transfer lever to the right and pull firmly rearward to 4L".

Click to expand...

Exactly... I knew I wasn't crazy :gee:

...AND check the T-case linkage if you are having trouble shifting/pulling the handle. Adjust, tighten and lubricate the joints/bolts etc. See that it moves freely and it's is not binding or loose.

Listen to magimerlin on the vacuum ports and lines. If the vaccum to the t-case is just flopping around and sucking air, maybe not so good... All the vac lines should be plugged and out of the way not connected to anything or removed altogether and again the ports on the t-case AND on the CAD actuator...capped off.

"To engage, shift the transfer case lever from 2H to 4H while the vehicle is moving at any legal speed". I let off the gas, throw the lever and then tap the gas and let off.

Click to expand...

I do this.
I've shifted into 4h at 80 before...

It seems the extra tension on the handle worked itself out. I ran it up Mt. Hermon Rd here this weekend and down a few trails. It shifts in and out of 4WD flawlessly now with no extra effort on the handle. I plugged the vacuum lines and the vacuum ports on the fork housing in case I ever want to go back to that cursed system. But all seems to be in order now. Thanks!

rmorton said:

It seems the extra tension on the handle worked itself out. I ran it up Mt. Hermon Rd here this weekend and down a few trails. It shifts in and out of 4WD flawlessly now with no extra effort on the handle. I plugged the vacuum lines and the vacuum ports on the fork housing in case I ever want to go back to that cursed system. But all seems to be in order now. Thanks!

Click to expand...

You'll never go back. I think you just need to use 4wd more often!!!

Some random bits of info...

1. when it says any legal speed, it means it - BUT you need to have your front to rear driveshaft speed difference minimized. So if you are stuck and spinning the rear tires, or accelerating in slippery conditions, back off the throttle while shifting. If you're actually stuck and the rear tires are just spinning, you need to hit the brakes, then shift into 4H while the tires are stopped, or just shift the transmission into neutral before shifting into 4H.
2. deleting the vac disconnect can affect 2H->4H shift firmness if certain things happen in a certain order. It's not important though.
3. If you don't do the vac disconnect delete and go 4 wheeling, you are at the mercy of spare shaft availability issues - your passenger shaft is not a common junkyard part anymore. On the other hand, if you do the vac disconnect delete, there are a whole lot of donors in the junkyards.
4. On that note, careful when selecting spares at the junkyard. Late 80s (iirc) and early 90s jeeps with no vac disconnect got axleshafts with the old style boxy inner shaft ujoint yoke that's a separate splined part pressed onto the end of the shaft. Those shafts may or may not fit into a vac disconnect housing that's been converted, depending on what blockoff kit you get (iirc.) I'm not exactly sure on specifics, but Saturday we discovered that a friend's spare long side shaft with the pressed on yoke would not fit into his converted vac disconnect housing and he ended up using one of my spares.