1976gmc20

Also back in that time frame (1990 +/-) I remember hearing about folks with S-10 Blazers that had a similar vacuum front axle disconnect that they had lots of problems with: no 4wd when they really needed it.


The full size Chevys are/were an electric disconnect and they regularly fail or just don't work when you need it most, like when it's cold and/or driving through deep snow. I shimmed mine with $0.05 worth of PVC pipe


And Jeep made the Cherokee with the NP242 with no disconnect even though the 242 does have a strictly 2wd selection. The early Jeeps had no front lock-out hubs; that was a civilian thing that came about later. It might have actually helped some for those who flat-towed a jeep behind a pickup/camper which was really common back in the 1950s and 1960s. But I think that would have had more to do with the steering free wheeling properly while being towed (???).

1976gmc20

BTW, can anyone explain to me why Jeep went to a front axle on the Cherokee that cannot use lock-out hubs ???


Seems like I remember that my friends' CJs all had lock out hubs back in the 1970s (along with all the other 4wds: Scouts, little Broncos, full size pickups, etc).

cruiser54

Because they went with unit bearing hubs?

Because they were appealing to professionals, housewives, and outdoor enthusiasts. Not us 25 years later.

1976gmc20

So it went like this ... they went from "inconvenient" hubs that worked to "convenient" vacuum disconnect that didn't work to just letting everything turn all the time, just like 1941. Okay I get it: progress!


Riddle me this, though: with the CAD doesn't that make the spider gears turn like crazy without the benefit of the ring gear to circulate oil ???


Seems like it's the same as having one hub locked and one hub unlocked, which of course we were told to never under no circumstances do back in the old days.

cruiser54

Thanks for bringing that up. Let's spin spider gears on cupped washers instead of spinning something that circulates oil while riding on bearings..........

1976gmc20

So I'm not wrong then


The front end will last longer if you leave the CAD engaged all the time.


(or don't have one to begin with, of course)

cruiser54

LOL. Interesting concept to say the least. Thanks again.

DFlintstone

The carriage, turning even lazy will lube things. If you want to see what happens when it's not turning, just park it for a month, then come back and check it!

AS far as you dodging my questions Pete...oh well to each his own. Things not moving won't wear. Things moving 1/2 full speed will wear 1/2 of what they would at full. A no braner, at least for me!

If I were a serous mudder I'd have the spiders welded, can the vacuum and run a cable to my disco for an (optional) full lock front axle.
(Not for highway use!)

1976gmc20

Seems to me like those spider gears would be running a lot more than half speed, considering they normally don't turn all that much unless you are stuck and spinning one wheel ???

cruiser54

Yep. Going straight down the road they're not spinning at all. Even in a turn they move just a little.....

Cjjcalhoun

this may seem like an argument to some but it is a wealth of knowledge to me.

I just lifted my 88 up 4.5 inches. Currently I have a group of vacuum lines just hanging out. I was going to go for some kind of extension but i believe i will just go with the permanent engagement of the CAD.

Most of us want to replace the DANA 30 with a "better" differential. More than likely the replacement won't have a disconnect.

DFlintstone

No Argument myself, just adding my .02. Cruiser has thought me Loads about Renix. I just happen to like my discos! My only one without one has problems..and it's a replacement 242. Sorry...... moving on ......

cruiser54

Interesting logic and deductive reasoning......

DFlintstone

Hey, You are a Mod with all sorts of access, right? Maybe count up the number of people who have had their spiders go, and cpmpare that to pinion bearings, or front u-joints, or what is un-necessately spun in the transfer case. IIRC the chain will also be full speed.

If oiling were an issue, with the right axle disconnected, that warm bath of oil, while lazily spinning with no work...Will keep it happy. The D30 in Brown/282K looks looks new to me.

cruiser54

Chains always turning. No matter which transfer case or axle in front.

The front output bearing isn't gonna wear out any earlier than the rear output bearing.

The front u-joints aren't gonna wear out nearly as fast as the rear ones.

How come ALL 91 and later XJs, ZJs, TJs, YJs, WJs, JKs, KJs, and MJs ad infinitum, aren't experiencing all the issues that you point out? Not to mention other manufacturers who decided the CAD was unnecessary...........

Risk versus reward. Do you want to risk some "supposed" wear and tear and miniscule loss of fuel economy in favor of not being stuck without your 4wd working and all the collateral damage monetarily, emotionally, relationally with all it's inconveninces or be rewarded with peace of mind.........