wranglercory Posted February 25, 2008 Share Posted February 25, 2008 I was looking at car-parts.com and they offered an option of a NP231 and I think the other was a 242 Police package or non Police. What is the difference between the two is the police one better ??? Link to comment Share on other sites More sharing options...
Pete M Posted February 25, 2008 Share Posted February 25, 2008 A 242 allows 4wd travel on dry pavement. A 231 requires a slippery surface or else damage is possible. I don't know the difference between the police 242 and the non-police 242. Link to comment Share on other sites More sharing options...
A-man930 Posted February 25, 2008 Share Posted February 25, 2008 I plan on going with a 242 sometime in the future. It was available in XJs as well as Dodge Durangos, Hummer H1s, and a few others iirc. The only "full-time" case worth getting as it is all gear-driven, no viscous couplings. Link to comment Share on other sites More sharing options...
LocoJeeper Posted February 25, 2008 Share Posted February 25, 2008 i have a 21-spline version pulled from an XJ waiting to swap into my 89 MJ. From what I understand its only incrementally weaker then the 231, and offers 4-wheel-all-the-time... which in DD is a good idea. A little bit of a hit in MPG, but i only drive 4 or so miles to get to work. You should also swap out the front axle to a non-cad (center axle disconnect) version in order to take full advantage of the all-time-4wd. God Bless, Ben @ Loco4WD.com Link to comment Share on other sites More sharing options...
Pete M Posted February 25, 2008 Share Posted February 25, 2008 I've noticed 0 difference in mpg between 2-hi and AWD in our Liberty. My theory is that essentially all the same parts are moving all the time either way. Just to clarify, the 242 isn't "gear driven" in the same way as the NP-205 or Atlas-2 are, but rather he's referring to the part of the t-case that gives you differentiation between the front and rear. The case is still a chain case like the 231. Link to comment Share on other sites More sharing options...
Eagle Posted February 26, 2008 Share Posted February 26, 2008 The 242 is not AWD -- it still offers a 2WD selection. It also offers 4-Hi with differential (AWD), 4-Hi locked (same as the 231 Part-time), and 4-Lo locked (same as the 231 low range). It's a great tranny for a multi-purpose vehicle that sees street use in slippery weather but also gets used off-road on occasion. The Hummer version is stronger, and I have seen conflicting information as to whether or not you can swap in some Hummer parts to beef up the Jeep 242. Link to comment Share on other sites More sharing options...
maddzz1 Posted February 28, 2008 Share Posted February 28, 2008 If i read correctly the 242 has more splines. Does this mean you also need to swap the DS or is it a direct swap? Link to comment Share on other sites More sharing options...
A-man930 Posted February 29, 2008 Share Posted February 29, 2008 yes, you can swap parts from an AMG (hummer) 242. I have a pdf file of pictures, but no write-up yet (can't seem to find it). Gimmie your email and I'll send you what I have. Link to comment Share on other sites More sharing options...
comanche89 Posted February 29, 2008 Share Posted February 29, 2008 which do you guys prefer the 242 or 231 Link to comment Share on other sites More sharing options...
Pete M Posted February 29, 2008 Share Posted February 29, 2008 Either one will work fine for most MJ owners out there. If your truck sees snowy roads, the AWD option in the 242 is nice. Link to comment Share on other sites More sharing options...
wranglercory Posted March 2, 2008 Author Share Posted March 2, 2008 I'm a little confused is the 242 a AWD and how is that different from my 231s Ive had that were 4WD . I want the best I can find at a reasonable price . Thats why I thought about the 242 , 231s seem to be pricey and in demand more . I am looking for a good TC , but when I saw the option for a police 242 I thought it might be a little stronger . Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 2, 2008 Share Posted March 2, 2008 I'm a little confused is the 242 a AWD and how is that different from my 231s Ive had that were 4WD . I want the best I can find at a reasonable price . Thats why I thought about the 242 , 231s seem to be pricey and in demand more . I am looking for a good TC , but when I saw the option for a police 242 I thought it might be a little stronger . the 242 is selectable 2wd, part time, full time, neutral, 4 locked, and 4 low locked it has a differential in it kind of like a axle...in otherwords, in it's unlocked version, it can't bind between front and rear tires, and hence can be street driven in unlocked 4wd on dry pavement. this makes it great for snowy/drifty roads that are dry/sno/dry/snow. you get the pattern. an np231 is only usable on the road in slippery conditions. there must be some slip at the tires, or the t-case will bind and cause detonation Link to comment Share on other sites More sharing options...
aerocorey Posted March 2, 2008 Share Posted March 2, 2008 231 can't be driven on dry pavement in 4H or 4L because it forces the front and rear driveshaft to rotate at the same speed. Imagine that you were rolling the Jeep around in a parking lot with the transfer case in neutral and the CAD locked. When cornering, the front and rear driveshafts want to rotate at diferent speeds because each wheel is rotating at a different speed. The differential in the front and rear axles allow for the different wheel speeds on each axle, but the result is that each differential produces a slightly different driveshaft rotation than the other. When driving a 231 in anything other than 2H the front and rear driveshafts are mechanically locked at the same speed. This results in the wheel hop felt during cornering in 4H or 4L on a dry surface with a 231. The outside front wheel is hopping to keep up with the inside front wheel in during the turn because the tires want to rotate at a diferent speed than they're being allowed. This binding is harmful to your driveline. 242 allows the front and rear driveshafts to slip some during normal operation so it can be left engaged on dry pavement without binding the driveline, thus leading some people to describe it as AWD rather than 4WD. If there's no viscous coupler in a 242 how does it operate? 229 is chain operated, but the chain is driven by a viscous coupler. 228 uses a mechanical differential to drive the chain, but they suck because all it takes is 1 wheel with no traction to get the whole thing stuck. I had a Grand Cherokee with a 249, also chain driven with a viscous coupling. The old FSJ Quadra-Trac used a bunch uf clutch packs to drive the chain, but it was still chain driven. Link to comment Share on other sites More sharing options...
Drahcir495 Posted March 2, 2008 Share Posted March 2, 2008 yes, you can swap parts from an AMG (hummer) 242. I have a pdf file of pictures, but no write-up yet (can't seem to find it). Gimmie your email and I'll send you what I have. Please share your findings! :bowdown: You need to start a write up on this! How hard is it to get an AMG 242? Have you tried it out yet? Sorry for all the questions - Rich Link to comment Share on other sites More sharing options...
aerocorey Posted March 2, 2008 Share Posted March 2, 2008 If I had to take a guess at the police package, it's probably just something like a slightly stronger chain. Link to comment Share on other sites More sharing options...
Recommended Posts
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 accountSign in
Already have an account? Sign in here.
Sign In Now