Hello, 2006 LR3 SE, when i first bought it the TCCM was bad and the Disco was stuck in low range (drove in low range fine). Had that replaced but then found the hi/low selector switch was bad. I finally got arround to replacing the hi/low switch and when I put in N and select low it switches now but when I put into D/R I just get a gear grinding noise and it won't move, when put back into HI it runs normal. I suspect the gears aren't fully engaging...could that be the transfercase shift actuator? Is their a calibration that can be done? Another thoughts? Thanks!

 

If there is an issue it should be generating a code, even if you get no warnings on the cluster. Pull codes. But it could be a bad transfer case itself, the shift motor, bad position sensor or the range change solenoid not working properly. Typical though if there is an issue it will present a warning, shift back to the previous state (high or low) and then disable itself and toss out codes. So it is really odd that it is not doing that which makes me think you have something odd going on. You could try calibrating it, but that is dangerous waters to enter as it may get stuck in low for good and you do NOT want to drive on pavement on low unless you want to replace the entire transfer case.

 

Honest question, and not to side-track the discussion, but....why is it bad to drive on pavement in 4-Lo at reasonable speeds?

I always understood that concern to be more about diffs being locked and causing stress in the drivetrain on high friction surfaces, as opposed to the gear ratios. With the LR3 being permanent 4WD and the diffs being computer controlled, is that still an issue?

 

Because in low the clutches are actually engaged in the transfer case when in low. And it is not a good idea to drive at a higher speed in low, so it is just not practical. I think the owner manual even says that low range should be used in a limited manner.

 

Found it.

 

This still does not answer the question what really defines an OFF RoAD conditions. In my mind ,driving in 4Lo should not be limited to steep ascents and descents according to LR explanation. I have used it in many other situations and terrains, in fact, I have had 4L engaged for entire White Rim Trail in Moab Canyonlands which is over a 100 miles long with no overheating or other problems. Obviously my speed was significantly reduced during the trip, but still a long drive nonetheless to drive in low range.

 

Its not, even though the manual exert that DT posted it only says " not to use for normal road driving " probably because numpties who don't understand might try and drive flat out in low and destroy the TC or gearbox.
Like you said if you are using it at low reasonable speeds there is no problem if you use common sense.