4WD Driving Issue

[JimiGibbs]

Been a while since I have used 4WD.... Actually been a while since I have done anything with my truck. Put in 4WDHigh and when I turn either way it jumps and has a very wide turning radius. I assume it may be something in the front differential (both wheels not turning the same) but not sure. Any ideas??? THANKS

[eaglescout526]

Sounds normal if you have command-trac NP231. 
 

The Selec-Trac cases have a differential in them that allows the front wheels to rotate at a different speed so you can use 4wd all the time if you’d like. At least that’s how the 228/9 works. Not entirely familiar with the 242 but I imagine it’s the same way. 

[JimiGibbs]

Thanks... but I think it should (and did if I remember correctly) turn more smoothly. It really hops.

[89 MJ]

Are you testing this on dry pavement?

[ghetdjc320]

If you are turning on a hard, dry surface, it will hop and buck like crazy. Good way to break u joints. If you’re going to drive in part time 4wd on hard surface, try not to turn 

[JimiGibbs]

It was on a hard dry surface so maybe it is normal.... I just don't remember it from before. Going to play with it some more tomorrow. THANKS ALL

[89 MJ]

Yeah, best to steer clear from doing that on dry, hard surfaces. That’s a good way to break stuff. 

[derf]

16 hours ago, eaglescout526 said:

Sounds normal if you have command-trac NP231. 
 

The Selec-Trac cases have a differential in them that allows the front wheels to rotate at a different speed so you can use 4wd all the time if you’d like. At least that’s how the 228/9 works. Not entirely familiar with the 242 but I imagine it’s the same way. 

The 242 is an evolution of the 228/229.  It got rid of the vacuum operated 2WD/4WD switch.  It also added a part time high range.  One manual shifter goes through 2HI/4HI part time/4HI full time/neutral/4LO part time.

 

And it has no limited slip in full time.  Fully open differential.

[llhat]

6 hours ago, derf said:

The 242 is an evolution of the 228/229.  It got rid of the vacuum operated 2WD/4WD switch.  It also added a part time high range.  One manual shifter goes through 2HI/4HI part time/4HI full time/neutral/4LO part time.

 

And it has no limited slip in full time.  Fully open differential.

 Novak's site i think phrases it differently....

 

the x case is 'locked' in full time,  and full time low

 

https://www.novak-adapt.com/knowledge/transfer-cases/np242.html

[Eagle_SX4]

14 minutes ago, llhat said:

 Novak's site i think phrases it differently....

 

the x case is 'locked' in full time,  and full time low

 

https://www.novak-adapt.com/knowledge/transfer-cases/np242.html

I swapped in a NP242 and @derf is correct about Part time (high and low range) being locked like a 231, only should be engage on slippery or loose surfaces. With full time being an open differential, being able to drive with it engaged all the time on any surface or "Full time".

[derf]

44 minutes ago, llhat said:

 Novak's site i think phrases it differently....

 

the x case is 'locked' in full time,  and full time low

 

https://www.novak-adapt.com/knowledge/transfer-cases/np242.html

I don't see that wording on that page.

 

In the bullet points:

 

four-wheel-drive, high (48/52 differential torque-biased-drive)
four-wheel-drive, high (locked, part-time)

[llhat]

maybe a misinterpretation on my part.... and confusion of part and full time...

 

'full time' would be all surfaces,  part time not for use at all times...

 

but how would the 'open' differential get a 48/52 bias  ?

 

my 89 believe has a 231 anyway...  

 

an 87 cherokee my sister has (now parked) had the 242 IIRC

my 94 GC had the 249.... with that dang viscous coupling

[derf]

1 hour ago, llhat said:

maybe a misinterpretation on my part.... and confusion of part and full time...

 

'full time' would be all surfaces,  part time not for use at all times...

 

but how would the 'open' differential get a 48/52 bias  ?

 

my 89 believe has a 231 anyway...  

 

an 87 cherokee my sister has (now parked) had the 242 IIRC

my 94 GC had the 249.... with that dang viscous coupling

It could be that it acts a little like a torsen limited slip differential.

 

When I rebuilt mine, it didn't have any clutches or anything like that.

[Pete M]

the 242 is not fully open-open, and will chirp the tires a bit pulling a tight turn into a parking spot.  I've been running my 06 Liberty in AWD continuously for years now.  IMO best t-case ever (unless you need hardcore strength).