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Willy Mo
May 19th, 2010, 14:44
Ok my vacuum actuator on my 91' doesn't work (its missing via previous owner) so my 4wd does not work at the moment. I saw this write up on the cherokeeforum.com
http://www.cherokeeforum.com/f51/free-d30-cad-bypass-91-a-38629/
has anyone done it?

the previous owner put a manual carb choke cable actuator on it but it was just thrown together and doesnt work. If there is a better solution please let me know.

Johnnie Walker
May 19th, 2010, 15:18
I have not done this, but know a lot that have. There are many ways to make your CAD work better, this being one of them. You can also purchase a kit called a "posi-lok" It makes the CAD cable activated and you engage/disengage it by moving a knob/lever.
You can also create a DIY version of that kit as well. I do believe there are a couple of write-ups on it either here or cherokeeforum.
Some have also talked about doing an Electronic push button version of the posi-lok style system as well.

1987Comanche
May 19th, 2010, 19:51
I didn't use this method: I found another writeup that suggested drilling a hole in the fork and using a bolt as a spacer (I think it was jpmagazine). I did it in Jan and it works fine. I do have a little vibration in the steering wheel a 65-70mph now but it's minor.

5-90
May 19th, 2010, 20:13
It's also possible to just get later shafts and convert the thing to not use the CAD in the first place. I don't recall the particulars, but I'm sure it's been discussed here before. Search, using keywords like CAD, disco, disconnect, conversion, or elimination; singly or in various combinations.

joe_peters
May 19th, 2010, 20:34
Options: http://www.jpmagazine.com/techarticles/drivetrain/axletech/154_0904_dana_30_vacume_disconnect/index.html

Willy Mo
May 19th, 2010, 21:12
thanks forthe help guys, I will be addressingthis issurethis weekend. along with many other issues like brake lights

Willy Mo
May 19th, 2010, 21:37
ok heres another question. I have a 93 parts jeep. with 4.0 auto and the aw4, 242 t-case. it has the D30 without the CAD. but the lower control arm mount on the passenger side is bent and the axel seals leak a lil. woudl it be worth my time swapping it?

I already swapped the 8.25 with my D35.

joe_peters
May 19th, 2010, 21:47
A**uming the D30 and 8.25 are from the same XJ and have the same ratio, why not? You will need to go through the seals, and you should heat that LCA mount and straighten it.

Or, you could just lock the D30 CAD for the short term and repair the other axle at your leisure.

Willy Mo
May 19th, 2010, 21:56
A**uming the D30 and 8.25 are from the same XJ and have the same ratio, why not? You will need to go through the seals, and you should heat that LCA mount and straighten it.

Or, you could just lock the D30 CAD for the short term and repair the other axle at your leisure.

thats kinda what i was thinking, and yes both my 91' and the parts 93' are autos and have 3.55's. but is the non CAD thats much better? are the axels stronger? they have larger u-joints?

joe_peters
May 19th, 2010, 22:08
It is stronger, but whether you break an axle is dependent on so many things--how you wheel, the terrain, tire size, open or locked, things like that.

Johnnie Walker
May 19th, 2010, 22:35
It's also possible to just get later shafts and convert the thing to not use the CAD in the first place. I don't recall the particulars, but I'm sure it's been discussed here before. Search, using keywords like CAD, disco, disconnect, conversion, or elimination; singly or in various combinations.

thats kinda what i was thinking, and yes both my 91' and the parts 93' are autos and have 3.55's. but is the non CAD thats much better? are the axels stronger? they have larger u-joints?

It is stronger, but whether you break an axle is dependent on so many things--how you wheel, the terrain, tire size, open or locked, things like that.
Basically with what 5-90 has stated, and since you have a non-CAD axle. You can swap the 1-piece shaft. Along with this you need to replace the inner seal, and the obvious outer seal since you would do the swap. Which also means you can upgrade the u-joints. So maybe you should swap in the driver side shaft from the non-CAD as well.

Willy Mo
May 20th, 2010, 06:51
so your saying just swap tel axle shafts and not the entire axle? to eliminate the CAD totally?

old_man
May 20th, 2010, 07:47
Back in the last century when I ran a D30 with a CAD, I found that there was a 297 based CAD axle available from a SWB Jeep but don't remember the model. Maybe someone can chime in.

I built a cable actuated system but found it of little use since I was running a lunchbox locker in the front and just put washers on the actuater shaft to force it to be engaged at all times.

ADVNTURR
May 20th, 2010, 10:56
The 95 YJ Sahara came with a CAD D30 that used 297 joints. I found a guy on craigslist selling just his passenger side so I grabbed it and grabbed a driver side from a junkyard leaving me with the CAD but running the bigger joints.

I had already invested in a Posi-Lock several years ago so I didn't want to go through the process of swapping out an entire axle or even going to a 1 piece shaft. I do now run an Aussie up front and like the fact that I can disconnect the right wheel to gain a little turning radius if I need to, but I typically just back up.

Regardless of the method you choose, upgrading to the larger joints is a good piece of mine swap, and while you are at it, it'd be a good time to convert them to full circle clips.

Willy Mo
May 20th, 2010, 18:03
ok i think i am gonna go the easy route and lock the cad in the locked posistion for the time being until I have the time to find either axle shafts or a dif D30. thanks for all the help.

keith_b00ne
May 31st, 2010, 18:44
I have never messed with a vacuum actuator, but mine isn't working either. I know I have vacuum lines leaking all over the engine bay. Currently I am trying to systematically cap or fix them. It is likely a leak, but can't be sure. Is there a way to narrow down if it is vacuum versus mechanical? Does anyone know where there is a diagram of the vacuum lines?

Willy Mo
May 31st, 2010, 20:40
i fixed mine be removing the actuator cover and removing the E clip, sliding the shift arem over and replacing the E clip so its always in the "locked" posistion.

keith_b00ne
June 15th, 2010, 08:55
Update for anyone interested. I tracked down the vacuum lines into the engine bay and I found a 3" piece that was broken off. The entire line is brittle. To get me in the woods I took a piece of hose and slipped it over both ends of the broken line and it worked great. It is a temporary trail fix, but it will last me at least until I can get to doing the modification.