np242 W/locker?

[Rod Knee]

What you lose with a NP242 and auto lockers is the ability to run the full-time on dry pavement, since the fully locked axles don't allow the t-case to differentiate as it's designed to do. The full-time is really handy for wintertime driving on mixed snow/ice and dry pavement roads. So as long as you don't use it on dry pavement in full-time, you're fine. It's designed to be used on dry pavement and other mixed conditions without having to shift back and forth, like an all-wheel drive car or SUV that you see so many of these days. Once you remove the differentiation from the axles by locking them up, you don't allow the full-time t-case diff to operate as it was designed, and it will fail if you do run it on high traction surfaces like pavement or slickrock.


Go with a selectable in the front, that's what most of us with the 242 have done. If that's not realistic, then just don't use the full-time.

In your first paragraph you seem to be saying that even an auto locker in the rear could cause failure of the 242 if the jeep is driven on hard surfaces. Then in your second paragraph it sounds like you are saying that its only the front that should not have an auto locker. I would appreciate a clarification since I have a 242 and am considering the pros/cons of various traction aids. Thanks in advance.

 

[nochance9]

I've loved both my 242s! Can't imagine swaping it for a 231, not saying the 231 is bad. Just that the 242 gives a nice medeum between 2 and part time for when the roads are bad but not bad enough to need part time. Which for me in northern utah is almost all winter long lol. Would't trade it for the world.

An auto locker in front however.... i'm not sure i agree with that, i mean i've never been in stuff crazy enough for me to think i needed a locker in the rear, not to mention the tire wear, clunk clunk around the corners, and the whole "forget about full-time." thing... But to each his own, i would sugest the auburn ecect or somethin like that... It's a LS unlocked, then when locked an electromagnet forces the clutch plates together for a full lock. Price wise is around $650 iirc. I don't think that anything that limmits your options is really an "upgrade," just me. Upgrades are suposed to GIVE you options, things that take options away are called compromises. Get a selectable and keep your full-time option.

 

[1990JEEPXJ]

rear locker is fine for a 242, in full time and part time. the only reason a front auto locker would be bad is because you could not turn without the front tires binding, nothing to do with the t-case itself since the front and rear driveshafts could still turn at different speeds. it just essentially renders the full-time option's purpose (street use) useless.

 

[nochance9]

In your first paragraph you seem to be saying that even an auto locker in the rear could cause failure of the 242 if the jeep is driven on hard surfaces. Then in your second paragraph it sounds like you are saying that its only the front that should not have an auto locker. I would appreciate a clarification since I have a 242 and am considering the pros/cons of various traction aids. Thanks in advance.

Ok, so let me take a whack at explaining this... Imagine your 242 as a differential like your axles. Full-Time would be like an auto locker, giving way when it senses a difference in drive shaft speed between your DSs which makes it good for the street for when you turn a corner your t case slips a bit instead of transfering all that stress through your axles and into your tires putting a load on everything. That is called Part time 4x4 which is like fully locking your transfercase, making it like a spool that will not give way no matter what, not good for street use. ( 4low is the same thing but with a funner gear ratio ) By putting an auto locker in the front you will be fully locked whenever it has power, meaning if you are in full time and you take a corner your tires will have to give. Same for the rear. So what he is trying to say is that by putting an auto locker in the front, or both ends (if only in the back people can deal with it, but keep in mind your back doesn't steer. That is where the difference lies in locking your rear and it being ok and locking your front and it being not ok for street use comes from) of your jeep will make your street friendly Full-Time setting totally useless on the street and in terrain with good tire grab. Dirt mud and snow give a ton as far as traction is concerned, that is why it's okay to have your rig locked off road. I don't think any transfer case let alone axles and u joints could handle the stress of driving fully locked at high speeds on the street for very long before you find the weakest link in your system. People with 231s don't have to worry about this because that don't have a very street friendly 4x4 setting to begin with so out of the gates they are kinda restricted to street 4x4 use and only put it in 4x4 whenn of road. :lecture: Whew..... Hope that cleared some things up.

 

[Rod Knee]

I understand why locking the front with a non-selectable would be a problem in full-time on hard surfaces. But once in a while you do come across a post, if you research locker/242 combos extensively,that suggests even an auto locker in the back could cause problems. Still seems to me like fubar XJ was trying to make that point in his first paragraph.

Something about sudden transfer of power to the locked axle (even the rear) causing excessive stress...

 

[themangeraaad]

Ok, so let me take a whack at explaining this... Imagine your 242 as a differential like your axles. Full-Time would be like an auto locker, giving way when it senses a difference in drive shaft speed between your DSs which makes it good for the street for when you turn a corner your t case slips a bit instead of transfering all that stress through your axles and into your tires putting a load on everything. That is called Part time 4x4 which is like fully locking your transfercase, making it like a spool that will not give way no matter what, not good for street use. ( 4low is the same thing but with a funner gear ratio ) By putting an auto locker in the front you will be fully locked whenever it has power, meaning if you are in full time and you take a corner your tires will have to give. Same for the rear. So what he is trying to say is that by putting an auto locker in the front, or both ends (if only in the back people can deal with it, but keep in mind your back doesn't steer. That is where the difference lies in locking your rear and it being ok and locking your front and it being not ok for street use comes from) of your jeep will make your street friendly Full-Time setting totally useless on the street and in terrain with good tire grab. Dirt mud and snow give a ton as far as traction is concerned, that is why it's okay to have your rig locked off road. I don't think any transfer case let alone axles and u joints could handle the stress of driving fully locked at high speeds on the street for very long before you find the weakest link in your system. People with 231s don't have to worry about this because that don't have a very street friendly 4x4 setting to begin with so out of the gates they are kinda restricted to street 4x4 use and only put it in 4x4 whenn of road. :lecture: Whew..... Hope that cleared some things up.

x2. So glad someone else typed that up before I got here :laugh: I was reading the thread and was going to explain in a similar way since I thought thats how it worked. Now you have confirmed my suspicions. I have a 231 so I dont have to worry about this.

The auto-lockers only lock if power is put to the axle... so technically you could run a front auto locker with a 242 in full time if you coasted through every corner (I think :laugh3.. however the point of full time is so that you CAN drive around corners in 4WD, so putting an auto locker up front & coasting kind-of defeats the purpose...

As nochance said, The reason for no front auto locker is not that the t-case cant handle it. It should be able to handle it fine. The problem is that if you put power to your rear axle with a locker while taking a corner, one of the two tires will scrub and lose traction (or both can lose traction if it is wet/snowy out). The front will do the same.. difference is that your front tires also do steering so losing that traction is much worse when driving at higher speeds on the street than it is in the rear end. idk about you, but I would much rather have the rear end scrubbing or get a bit loose rather than having my front end lose traction and put me into the woods.

NP231 guys cannot use 4wd on the street unless the conditions are bad enough to need it (deep snow or the like), so we will never put power to the front axle on the street anyway, making an autolocker OK. Personally I would still do selectable in the front (so I could street drive in 4WD in the snow w/o any adverse affects), but that's just my opinion.

 

[Phil]

Time for an Atlas.

 

[fubar XJ]

In your first paragraph you seem to be saying that even an auto locker in the rear could cause failure of the 242 if the jeep is driven on hard surfaces. Then in your second paragraph it sounds like you are saying that its only the front that should not have an auto locker. I would appreciate a clarification since I have a 242 and am considering the pros/cons of various traction aids. Thanks in advance.

You can't use the full-time on dry pavement conditions with auto-lockers front and rear. This includes mixed dry/snow pavement conditions, which is where I use my full-time almost exclusively. With an open front diff, (which includes a selectable locker in the open position) you still can run full-time under said conditons.

Sorry if I wasn't clear enough.

 

[4x4JeePmaNthINg]

is a rear auto locker then a difficult traction device in full time? for myself full time is for snow or offroad use, maybe bad dirt roads for extra grab/safety. If locked front or rear is an issue for us 242 users does a front trac lock suit 4x4 better in More applicable traction situations?

 

[Rod Knee]

The most useful application for FT 4wd is on-road where alternating slick and dry stretches of road exist. This is especially so when it is often difficult to anticipate where the slick (ice) stretches are. FT is not particularly advantageous off-road.

Having said that, note that this thread is seven years old and your questions have been addressed in your other thread. Not trying to be a smart @$$, just sayin'.

 

[dantheman!]

so what are the SYE options for a 242? i plan on keeping mine vs swapping in a 231 but it seems like most of the 242 options involve a hack and tap which im not really wanting to do. Id rather a traditional SYE.

Am i just blind?

 

[ehall]

Advance Adapters makes a "real" SYE for the regular-duty NP242 http://www.advanceadapters.com/products/50-7921-np242j-fixed-yoke-kit/

Tom Woods bundles it with a driveshaft (note that it is an "HD" SYE for the 242-J, not an SYE for a 242-HD) http://www.4xshaft.com/SYE/242HD.html

I am using that in my POS with WJ front driveshafts in both the front and rear

 

[dantheman!]

thank you!

 

[bwinter1946]

I installed the Tom Woods SYE and driveshaft system. Works great. Easy install. I did not remove the transfer box to install and would do it again. Good, flat tip, external snap rings pliers and Permatex "Right Stuff" silicone sealant HIGHLY recommended. I went slow and if memory serves it took about three hours.