Filters get dirty from normal use, just like the engine the trans has moving parts that wear and those pieces have to get filtered out, once the filter is clogged...if you never changed the oil filter it too would get clogged eventually.

It is recommended that you change the trans fluid every 30,000 miles and the trans filter every 60,000.

 

OK FOLKS! All fluids in both front and rear differentials and the transfer case were changed and filled to the correct levels. Drive is much smoother especially when turning. There was some VERY VERY fine goop on the "magnet" in the transfercase drain. Oil removed from BOTH front and rear diffs was VERY foul smelling and was still pretty thick. Transmission fluid was NOT changed yet but I had 3/4 of a bottle of lucas trans fix and put that in. VASTLY improved shifts when operated in "manual mode". durastically reduced harshness and driveline hum. Vehicle generaly feels more fluid now.

Problems remaining:

Still has the REALLY loud deceleration groan(under throttle lift/engine braking). Tomorrow I am going to attempt to just grease the life out of all the U Joints and see if it even temporarily stops the deceleration noise. The noise sounds like its comming from just about the middle of the bottom of the vehicle. It feels like there is some sort of bearing that is so dry or worn that when it freewheels it oscillates or vibrates around in its bore instead of just spinning on its bearings.

The transfer case selector is still stuck in 4 Unlocked High.

The transmission still needs to be operated in "Manual mode" (1-2-3-D-3-2-1 and so on). Think manual valve body

Any insight is vastly appreciated!

 

In the rave manual, they list diagnostic fault symptons and causes for the trans

below in my sig if you don't already have it.

luck,greg

 

Fault says and I quote verbatium: "No 2 Freewheel"

Can someone translate this? Do I have a faulty solenoid or stuck valve?

 

Yes the solenoid may be bad and it will not let you shift into lo, but thats all it does is keep you from shifting into lo so as not to explode your truck at 80 mph by accidentally shifting into lo range.
You can still shift into lock at any speed.
You need to crawl under the truck and have a friend wiggle the t-case shifter, watch what moves and use carb cleaner on it, do that 3-5 times, let it dry then repeat with Liquid Wrench 3-5 times, keep working it, let it soak, work it, repeat.
You may need to remove the linkage and free it up, or you can just try and force it like I did after a weeks worth of soaking.
The worst that will happen is you bend the linkage and you will need to replace it, that did not happen to me.
Be patient yet stubborn with it, its a Rover.

As for the trans, change the filter.

 

Check your right side transmission mount... Mine was damn saugy... Once you know what to look for its pretty obvious how this could affect the LOW shifting problem and vibrations.... Its cheep, only $20.... I have the same problem with mine not shifting into LOW4x4 and the same noises you are talking about as of a the past month or so... Mine just got here a couple of hours ago.... Will put it on this evening and let you know if it fixes the vibrations and or the locked out of LOW4x4 problem...

 

Ok, just put on new right side trans mount and no luck with the 4x4LOW shifting problem.... Either way this thing was in desperate need of replacement, the old one was split in two... It was worth a shot....