Newbieish Question, Need Explination

[sinnaevd]

1) What's the difference between part-tim 4WD and full-time 4WD

2) Which is better for what applications and why

 

3) do you think i should 232 or 242?

[randimal]

I'll give this a shot though I may be wrong.

 

I believe part time means that both driveshafts are moving at the same speed. You are only supposed to use it on wet, or slippery surfaces. Once you hit dry pavement, you have to turn it off.

 

Full time has a differential between the front and rear driveshafts. It allows all four wheels to move at different speeds if necessary. Therefore, there's no reason you can't drive it on dry pavement. The only problem is if you completely lose traction on one wheel, the other three can sit still while it spins. In those cases, you can swich into part time, so two wheels are guaranteed.

 

I have an NP242 and I like it a lot. I only switch to part time when it gets really tricky.

[Oizarod115]

I'll give this a shot though I may be wrong.

 

I believe part time means that both driveshafts are moving at the same speed. You are only supposed to use it on wet, or slippery surfaces. Once you hit dry pavement, you have to turn it off.

 

Full time has a differential between the front and rear driveshafts. It allows all four wheels to move at different speeds if necessary. Therefore, there's no reason you can't drive it on dry pavement. The only problem is if you completely lose traction on one wheel, the other three can sit still while it spins. In those cases, you can swich into part time, so two wheels are guaranteed.

 

I have an NP242 and I like it a lot. I only switch to part time when it gets really tricky.

 

pretty much nailed it...

 

go to jeep.com and check out the liberty 4x4 stuff... they have an animation that shows it... (liberties have the same t-case options as XJ/MJs)

[DirtyComanche]

Actually... The NP242 does not use a differential. It uses a planetary gearset that splites the torque between the front and rear in 48/52 bias or 'something'.

 

 

I've never tore one down. But they don't work like newer full-time tcases that use a differential or a viscious coupler.

[Oizarod115]

Actually... The NP242 does not use a differential. It uses a planetary gearset that splites the torque between the front and rear in 48/52 bias or 'something'.

 

 

I've never tore one down. But they don't work like newer full-time tcases that use a differential or a viscious coupler.

 

thats where its confusing because it DIFFERENTIATES... without a differential... :brows: i love engineers :hateputers:

[feerocknok]

The basics are the same though.

 

Think of your t-case like an axle, and your driveshafts like axleshafts. A full-time case is like an open-diff axle. Both driveshafts will spin when they have traction, but when one shaft loses traction, the other shaft stops spinning. A part-time case in 4wd is like a locked axle. The driveshafts will spin at a set rate, and when one end loses traction, the other end will still spin.

 

If you're into off-roading, I would imagine you'd want a part-time case, but I was thinking that the 242 has a part time option (center differential locker). Is that right?

[DirtyComanche]

If you're into off-roading, I would imagine you'd want a part-time case, but I was thinking that the 242 has a part time option (center differential locker). Is that right?

 

Well, it doesn't actually have a differential. It's a planetary gear set. Part time and Full time are the same other than it does some magic to bias the torque (I THINK it is wheel speed actually). But, off-road using it in part-time works best. (Yeah, it has part and full time)

 

 

Now, if you wheel a newer jeep with a part time/full time tcase, full time is useless off road. The viscious couple simply slips and you have a nice one tire spinning effect and then I start swearing at the stupid luxary 05 WJ thingo that I borrow from my mom to go wheeling in because I figure dying young will at least not be boring.

[sinnaevd]

so for offroading purposes a 231 would be a better choice is what I'm getting from this?

[ryno1121]

Actually... The NP242 does not use a differential. It uses a planetary gearset that splites the torque between the front and rear in 48/52 bias or 'something'.

 

 

I've never tore one down. But they don't work like newer full-time tcases that use a differential or a viscious coupler.

 

thats where its confusing because it DIFFERENTIATES... without a differential... :brows: i love engineers :hateputers:

 

Easy on us now!! :D

[Oizarod115]

Actually... The NP242 does not use a differential. It uses a planetary gearset that splites the torque between the front and rear in 48/52 bias or 'something'.

 

 

I've never tore one down. But they don't work like newer full-time tcases that use a differential or a viscious coupler.

 

thats where its confusing because it DIFFERENTIATES... without a differential... :brows: i love engineers :hateputers:

 

Easy on us now!! :D

 

hehe, you're just tricky! always coming up with better ways of doing things.

 

 

but there's no reason to not have a 242 just because you're gonna go wheeling... it has 2wd..fulltime, part-time hi and part-time low.

 

the only reason its better is if you drive alot of semi-slippery road conditions like snow or rain... it is AWESOME in the ice/rain