Thread: Discovery G.Box/T.Case whine - speed related

Cheers Ladas, well I'll try it this morning just in case - it'd be so good if that was all it was!

There is a light that comes on in the Disco S1 when CDL is engaged. I'm pretty sure that when you put the Hi/Low Gear leaver into Diff lock side it engages a vacuum CDL - I don't as yet have front/rear diff locks (anyone wanna donate some).

There are currently only two main vacuum lines off the engine... one to the brakes, the other to a funny box then under the car (assumed to CDL).

Like I said I'll try reversing today as it'd be good if that is all it is ;-)

Thanks,

chosen.

Originally Posted by chosen

Cheers Ladas, well I'll try it this morning just in case - it'd be so good if that was all it was!

There is a light that comes on in the Disco S1 when CDL is engaged. I'm pretty sure that when you put the Hi/Low Gear leaver into Diff lock side it engages a vacuum CDL - I don't as yet have front/rear diff locks (anyone wanna donate some).

There are currently only two main vacuum lines off the engine... one to the brakes, the other to a funny box then under the car (assumed to CDL).

Like I said I'll try reversing today as it'd be good if that is all it is ;-)

Thanks,

chosen.

The CDL on a D1 is a mechanical device, it doesn't use a vacuum - unless of course yours has been modified.

From the hi-Lo / diff lock lever next to the gear stick - there is a mechanical linkage to the CDL actuator.............again unless yours has been modified.

If you PM me your email address I will send some pictures/details of the linkage

Where is this 'funny' box under the car ? Do you have pics ?

The HI/Low lever in the D1 is a mechanical linkage to the transfer case.

The other vacuum line you saw is most likely the one for the cruise control, which goes from the throttle body to the vacuum control box in the front left of the engine bay.

Only the later D2's had vacuum activated transfer cases, due to LR removing the linkage to the lever.

DOH...just beaten by Ladas...!!!

Originally Posted by Caveman

Only the later D2's had vacuum activated transfer cases, due to LR removing the linkage to the lever.

Only LT95 4 speed transmission / transfer cases had vacuum operated diff locks. All LT230 type transfer cases are pure mechanical engagement from factory. Some Disco II transfer cases do not have any diff lock activation at all.

Originally Posted by BigJon

Only LT95 4 speed transmission / transfer cases had vacuum operated diff locks. All LT230 type transfer cases are pure mechanical engagement from factory. Some Disco II transfer cases do not have any diff lock activation at all.

As BigJon said - however some people who did not have any diff lock actuators have fitted after market ones, some being linkages, some being electric motor driven (AMV) some with linkage adaptors that work off the high low - giving you CDL in low only, and I do understand that some vacuum aftermarket adaptors were fit - but all these were aftermarket jobbies - on the D2 - 1999 - 2003 range. Some D2's (late 2001 - late 2002/early 2003) didn't even have the 'guts' of the CDL inside the transfer case, and that is a whole new ball game - isn't it Jon

I have had a similar problem in my disco.
The answer was the transfer case intermediate shaft lost its preload and created a wear pattern on the gears.
So even when it was rectified it would still whine loudly.

Originally Posted by jddisco200tdi

I have had a similar problem in my disco.
The answer was the transfer case intermediate shaft lost its preload and created a wear pattern on the gears.
So even when it was rectified it would still whine loudly.

That's interesting, did it still make a (now let me describe it right) gritty sounding, slightly crunchy vibrating whine when the Hi/Low gear box was in neutral and you go through the gears - especially in 4th and 5th?

I took it for a nice and long reverse drive just now and it has made no difference - end of diff lock theory???

The sound as I just described is being produced even when the Transfer case isn't engaged - would this mean that the problem is with the gearbox?

Thanks again to all who have commented thus far,

chosen.

Originally Posted by Caveman

The HI/Low lever in the D1 is a mechanical linkage to the transfer case.

The other vacuum line you saw is most likely the one for the cruise control, which goes from the throttle body to the vacuum control box in the front left of the engine bay

Ok, this is a photo of the funny box...


The cruise control has also just recently stopped working (for another post on another day) - wanna test that very vacuum control box once this whine problem has been rectified.

Any idea what that funny vacuum box thingy is for guys?

Cheers,

chosen.