Jump to content
Mopar1973Man

CAD Axle violent release.

Recommended Posts

I know this isn't exactly diesel related but on my 1996 Dodge Ram 1500 the CAD axle tends to hang up once engaged. Then when you you try to disengage the 4WD the lever goes to 2WD just fine and the transfer case releases. But the CAD unit holds the axle for extended period like maybe another mile or so. POP! Violently releases you can feel it in the entire truck. I'm not liking the CAD units at all I rather have a solid axle personally way less to go wrong. :rolleyes:

Share this post


Link to post
Share on other sites

The CAD box tends to hold any condensation and things can get a bit gummy and or rusty inside. Only 4 bolts to pull the cover off and inspect. I have seen other issues inside too but since it does still engage and disengage I would look it over for a reason to be hung up. The splined couplers can get an edge on the if slow to engage from grinding and this will cause it to uncouple hard as well.If you have a hand vacuum pump it is easy to test the diaphragm once it is apart too.

Share this post


Link to post
Share on other sites

Not even a gasket if I remember right. They are a simple unit.

Share this post


Link to post
Share on other sites

Any updates??:popcorn:

Well if I can get time between all the fire dept meetings and fire dept activities right now. I would look. But now I'm house sitting and running back and forth keeping there fire burning at a fires house so the place doesn't freeze up. Tomorrow I got to hold a class on how to "Install VP44 injection pumps" for a local shop because no but myself will do them. So maybe by next week or today if I'm not swamped. @AH64ID This is only a cheap 1500 Ram its not worth the price of delete kit nor a bunch of conversion. I don't think I can get much more than $2k for the truck way it stands. Now if I got the interior cleaned up and a paint job. Maybe...

Share this post


Link to post
Share on other sites

@AH64ID This is only a cheap 1500 Ram its not worth the price of delete kit nor a bunch of conversion. I don't think I can get much more than $2k for the truck way it stands. Now if I got the interior cleaned up and a paint job. Maybe...

But what happens when it fails to engage?

Share this post


Link to post
Share on other sites

But what happens when it fails to engage?

Um, it is called a two wheel drive??:smart::lol:

Share this post


Link to post
Share on other sites

I figured it would be more :mad::mad:

I know....... "Everybody likes a little a$$, but nobody likes a smart a$$"......:tongue:

Share this post


Link to post
Share on other sites

That's where I differ from most I don't use 4WD very much. Even out here in the snow and frozen roads I typically leave it in 2WD. As for the CAD unit on the 96 it always engages but hangs up on release. Because the simple fact is 4WD will give you traction to climb a slick grade but 4WD will not keep you from sliding off a highway. So my 4WD is a "Ace up my sleeve" so when I need it I've got it but normally don't need it. So many vehicle around me that are strictly 2WD pickup, cars, utility trucks and fire trucks etc. They don't require 4WD for winter travel just a Smart Driver.Like suggested above the vacuum might be the cause of the hang up and not pulling the collar back to release?

Share this post


Link to post
Share on other sites

If I recall it takes vacuum to engage the collar. It sounds more like the collar or actuator needs cleaned up to me. I am the same as you Mike. 2WD until you need 4WD and as soon as you can go back to 2WD.

Share this post


Link to post
Share on other sites

I generally run in 2wd as well, just depends on the conditions. But it's always nice to have! Another thread, but I really want a transfer case with a full time option. Does it use vacuum to engage or disengage, or both?Posi lok is a cheap and nearly bulletproof fix/upgrade, to me it seems like a no brainier to get it fixed and working properly. It's obviously having issues, so it's hard to say it will always engage and you wouldn't want to get stuck because of it.

Share this post


Link to post
Share on other sites

John, it looks like it uses vacuum for both engage and disengage.

Mike, do like Bill said and check the hoses over good. It may be leaking some vacuum on the disengage side.

Posted Image

Share this post


Link to post
Share on other sites

If I recall it takes vacuum to engage the collar. It sounds more like the collar or actuator needs cleaned up to me. I am the same as you Mike. 2WD until you need 4WD and as soon as you can go back to 2WD.

I'm pretty sure it takes vacuum both ways, otherwise it would just use a vent rather than completely diverting the vacuum from one side to the other. I played with it a bunch and I'm pretty sure without vacuum it doesn't do anything. The system is simple, the valves are cheap.. The design saves the u joints in the driveshaft. Its a good system if it works.

Share this post


Link to post
Share on other sites

That's kinda what I figured. So that tells me there isn't a vacuum issue, but more than likely an issue withy the CAD itself. Cleaning might work, and be free but if any parts are needed I would delete the vacuum portion at a minimum.

Share this post


Link to post
Share on other sites

If I recall it takes vacuum to engage the collar. It sounds more like the collar or actuator needs cleaned up to me.

I am the same as you Mike. 2WD until you need 4WD and as soon as you can go back to 2WD.

Out here the roads are spotted black ice might have a 100 yards or 1 mile stretch of ice. Instead of in and out of 4WD I gotten used to just backing down the speed travel the slick areas cautiously and then when in the clear pick up the speed to what I'm comfortable with.

I generally run in 2wd as well, just depends on the conditions. But it's always nice to have!

Does it use vacuum to engage or disengage, or both?

Posi lok is a cheap and nearly bulletproof fix/upgrade, to me it seems like a no brainier to get it fixed and working properly. It's obviously having issues, so it's hard to say it will always engage and you wouldn't want to get stuck because of it.

Thanks to ISX. Black vacuum line is to engage and the red to disengage.

Posted Image

Posi-lock is way over the top. Once again this is a low budget truck that has zero value where something like my Cummins still holding excellent value I can and would do something like that if I had a CAD axle. But this 96 Dodge the blue book... Well look for yourself it's not worth the effort.

post-2-138698211817_thumb.png

Share this post


Link to post
Share on other sites

I agree with you, Michael. The vacuum system has worked for 17 years, so why not fix it for another 10+ years? That in all reality would outlast the truck.

  • Like 1

Share this post


Link to post
Share on other sites

i remember with the older Jeep TJ's and YJ's that had a similar setup we used to take it out and slip a long shaft in it's place. or there is a cable actuator that way it's never an issue again. food for thought.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



×