SteveMongr

Dave, you and I both seem to read/post in the morning.
..Here is a cut-away picture of the 242 showing the internals.

dave1123

Yes, do you see that gear cage near the chain? That's the planetary differential. In Full Time the drive is thru that and causes the power to divide to allow different speeds for the axles. In Part Time, that unit is bypassed to allow direct drive to both axles. That heavy planetary section at the bottom is the low range gearing. In 2wd, the power is directed straight thru from the input shaft to the output shaft.

I only work 3 nights a week from 11 PM until about 6 AM so you can find me here at any time unless I'm sleeping or taking care of personal business.

99Justin4.0

This is helpful information.

I suppose you guys know mpg difference from 2wd to Awd?

And do you think utilizing the AWD more raises the likeliness that something will break? I've heard it's a good idea to used them every now and then, just to keep them oiled up (use it or lose it...). But these should probably only be used when necessary huh?

SteveMongr

To clarify, a vehicle considered AWD is designed for pavement and is very different from a 4x4 system.

Driving the jeep in Full-Time 4x4 does not affect fuel efficiency, according to the owners manual. Also states that can be driven for any length of time or distance.
Some folks leave it in Full-Time all winter long. I leave mine engaged for weeks or months at a time too, driving from pavement to sand and back.
Arguably, it could be beneficial to run in FullTime more often because it reduces stress and wear from rear driveline.

dave1123

It's a known fact that 4wd doesn't effect fuel mileage with jeeps because even through you don't have the front axle under power in 2wd, you're still turning the gears in the diff and the driveshaft. Plus, as was stated, the rear diff gets all the wear in 2wd so there are more chances of problems with it.

ZJs and XJs always had a problem with the t/case shift linkage getting rusty and locking up because it's exposed to weather and dirt. The newer WJs and probably the newer XJs shift by cable so they are less effected by this.

As Steve said, a lot of people drive all winter in Full Time. I do myself when there's snow or ice on the ground, shifting back to 2wd when the roads are bare for a while. I also use 4wd in heavy rain because the jeep feels more stable on the road and thru deep puddles. It also tends to equalize tire wear.

99Justin4.0

Yes I look at the Selec-Trac AWD just like a Subaru or something. 4Low is 4x4 to me. I kinda like the way it feels in full time 4. Corners just feel better.

Now, do you think it affects highway speeds?

You guys are so helpful for me understanding this machine. Thanks again to all of you!

jon-d

I really like the 242 TC even though I am in a desert climate. last weekend I was on a run that was mostly paved but occasionally off road to navigate around a barrier or something. I just left it in 4x4 full time and never had to stop and shift or play around with the TC shifter. it worked great.

dave1123

You know, that's the reason jeep went with the 249 and later the 247 and Quadratrac II. People, especially women, didn't want to mess around with a shifter and would rather have it in 4wd all the time. As I've said, the 242 in Full Time does have it's limitations, but all in all, it works very well for this purpose.

99Justin4.0

It was raining pretty hard when I left the grocery store so I put it in full time 4 while I was still in the parking lot. When I was turning the sharp corner out it did that tire skip thing again. When I got home I started doing really slow sharp turning back and forth and it was fine. I wonder what the deal was at first. Maybe it hadn't fully engaged yet?

Also, my heater doesn't ever seem to get very hot. It does when I take the radiator cap off. I keep thinking I've got air pockets, so I take the cap off and run it a while. I have to wrap a towel around the fill hole because it starts to spill over. Anyway, the heater got hot again, but then my reserve tank got low and the warning came up. Obviously it was because I let a bunch overflow out and soak in to the towel. But after I filled it back up to the "full" line on the reserve tank, when I shut the engine off, I can always hear some weird water noise coming from my heater for like 10 seconds. The hardly ever breaks 210. I mean I have to be stuck in a drive through line for a while before it breaks 210, but then it cools right back down. My dad's Dodge makes that noise when it gets too hot. But mine only makes the noise when I have the reserve tank all the way full. I should have just let it be when it was an inch below full... What a weird quirk!

My guess is I need to have it flushed good at a shop one of these days. I bet the heater core is just full of crap. It sucks I'm out of money and the rear axle bearings didn't get done, and the heater only blows slightly warm... Everything else is perfect.

My uncle with a 4.2L Scrambler was freakin blown away when he saw and heard my engine. He knew I did it, but it didn't catch his attention till I opened the hood and turned the key. He literally looked at me with shock on his face and said "you did this!?". I had already told him I completely rebuilt it, but I guess it went over his head till that moment. Then I got to tell him EVERYTHING I did. He was telling me all about Golen 4.6L Stroker Engines. I guess that's what he's gonna put in his. They look pretty cool but I haven't done much research on them yet.

dave1123

Make sure the heater supply hose from the thermostat housing goes to the bottom pipe on the heater core. That way any air in the core will exit thru the water pump naturally. It's entirely possible you've got air trapped in the core.

Your uncle probably thought it was just talk until he had it stuck in his face! I love it! My Dad thought the same thing about my SS Camaro until he drove it! Yeah, kids can do stuff too! My mom asked to drive it once, then decided it was too much for her. It was pretty brutal if you whamped on it. After all, it was a special high performance 350 with the Corvette cam in it. It also had the Dana Engineering 3 leaf rear springs designed for the 396 option. I used to get off just causually running it up thru the gears at partial throttle, feeling the smooth pull of it.

SteveMongr

Could try flushing the core yourself with a garden hose, using the heater hoses. Flush both directions, then blow out with compressed air to remove tap water. Fill with distilled water only.
My XJ would sometimes skip a front wheel when in 2WD and turning tight. I could not find an issue with sticking brakes or bad wheel bearing, I figured it was due to scrub radius.
Sometimes the 242 can be tempermental. Occasionally I have shifted it into Full-Time with transmission in gear and yet it remained in Part-Time until I moved transmission to neutral. All 3 of my 242 transfer cases have been this way, including a freshly remanufactured one.

99Justin4.0

It's been raining HARD around here so I've just left it in full. I haven't used it at freeway speed yet. I really like it better, but it just feels wrong. I feel like it's slowing me down, drinking more gas, and/or I'm gonna break something... It's probably in my head. I'm so used to my VW's and Porsche breaking I'm always all tensed up when I use things like that... I guess the sound of the rear axle bearings doesn't help things.

So the Quadra is basically the same thing as Selec, just without the 2 wheel option?

dave1123

No, Quadra uses a limited slip clutch between the axles, Selec uses a differential, unless you go to Partime.

99Justin4.0

Well, I'm rollin up on 1,000 miles pretty quick. Not a hiccup so far. I wish my heat was warmer, and I'm still listening to noisy rear axle bearings. But other than that, I can't complain about a thing.

So, I'm about ready to put some real oil in. Before I did all this work I bought two gallons of Rotella 5w40, but I took that back and just got some cheap stuff for the break in. I wanted the 40 weight thinking it might quiet it down when it was ticking. I think I'm still gonna go with the Rotella though. Just 5w30. Wix filter. I can't wait to see what the oil looks like. I'll run it through a paint strainer. I've heard it's crazy how much stuff you find in the break in oil. This thing has run smooth as can be since I first turned the key, so I'm not expecting much really.

One of the guys at AutoZone was super hyped up about the Nano Stabilizer. Apparently it's military tested and used. "Nanites" or something fill every little microscopic crevice. It's supposed to make oil have super viscosity I guess. But it's $30 a bottle. I think I'll just go with the Rotella and a Wix for now. Maybe Santa will put new axle bearings and Weather Tech Floor Liners in it while I'm sleeping...

But anyway, all is awesome! Couldn't be happier with the way everything has fallen in to place with my WJ.

dave1123

When I broke in my Hemi, I changed the oil and filter at 200 miles. I cut the filter open and flushed it over a piece of white bedsheet. All I found was a few aluminum chips from the pistons that I probably scuffed off putting them in and a few carbon particles, probably from somewhere in the block. Nothing stuck to a magnet.

After another 800 miles, I changed it again and it was clean. Good to go, I guess!