Matthew Currie
NAXJA Member #760
- Location
- Vermont, land of big clay
This question keeps coming up with regard to how one should or should not dolly-tow an XJ with NP 231, so I checked mine, and found that there must indeed have been a change of design somewhere along the way.
The NP 231 out of an 89 XJ definitely, and definitively, locks both output shafts together in neutral. This is as expected, and as all the owners' manuals I've seen imply.
But I just tested my 99, by jacking up only the left front wheel, and just as definitely, the wheel turns, indicating that the output shafts are not locked together. In 4 high and 4 low, the wheel does not turn. In N, it does. The transfer case is also definitely not broken.
Some time when it's not dark and snowing outside, I'll try my 95 and see which type it has.
I know that some time during the 95 model year, they dropped the synchromesh from the NP231, and wonder if this is also the point at which the neutral behavior changed.
In any case, it's easy to test, if you have a non-disconnect axle. Just jack up one front wheel, leaving the other three on the ground, and try turning it with the TC in N. If it turns, you know it's turning the driveshaft, and thus it must be uncoupled from the other driveshaft. I'd be interested to see what results come from non disco models prior to '99.
The NP 231 out of an 89 XJ definitely, and definitively, locks both output shafts together in neutral. This is as expected, and as all the owners' manuals I've seen imply.
But I just tested my 99, by jacking up only the left front wheel, and just as definitely, the wheel turns, indicating that the output shafts are not locked together. In 4 high and 4 low, the wheel does not turn. In N, it does. The transfer case is also definitely not broken.
Some time when it's not dark and snowing outside, I'll try my 95 and see which type it has.
I know that some time during the 95 model year, they dropped the synchromesh from the NP231, and wonder if this is also the point at which the neutral behavior changed.
In any case, it's easy to test, if you have a non-disconnect axle. Just jack up one front wheel, leaving the other three on the ground, and try turning it with the TC in N. If it turns, you know it's turning the driveshaft, and thus it must be uncoupled from the other driveshaft. I'd be interested to see what results come from non disco models prior to '99.