Diff lock "use it or lose" it: tips?

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Top of pagePrevious messageNext messageBottom of pageLink to this message   By Geoff on Saturday, March 17, 2001 - 11:40 am: Edit

I've seen this post for several years now, across many different boards. And it's certainly great advice--I just wish my Disco's previous owner would have known that. I recently had to replace the main linkage to the diff lock on account of it seizing up just about every month (only can do so much...).

But the fact is, time is an increasingly important commodity to me, and off road events are becoming ever-less frequent. So what's the best way to keep the diff lock conditioned?

Clearly, using it with the Disco's shoes on pavement is a bad idea. And the chance for snow in the midwest is also lessening with each day. What's the best way to engage the lock every so often?

Any tips are greatly appreciated.

Geoff
'95 Disco, 83K

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Clint on Saturday, March 17, 2001 - 11:53 am: Edit

Well,
you can engage the lock while it sits in your driveway every night. Also there is nothing wrong with popping it in and out of lock while driving straight. As far as keeping the linkage free, it's probably the number of cycles not total time in lock that is important. Having just fixed mine, I will certainly lock up every now and again to keep everything free.

Clint

Top of pagePrevious messageNext messageBottom of pageLink to this message   By DM on Sunday, March 18, 2001 - 08:24 am: Edit

My 97 Disco, since I got it a few hundred miles ago, has the Diff Lock in the H position...

Is this bad??

I am very new to the Disco scene, and don't even have an owner's manual for the thing...

I am trying to learn as fast as I can, but I'm really concerned about the diff lock now that I read this post!

How the hell do you use the diff lock correctly? What postion is it supposed to be in for daily driving? Even further, how the heck do you move the selector (mine doesn't seem to move)!

Thanks!

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Axel Haakonsen (Axel) on Sunday, March 18, 2001 - 09:28 am: Edit

There is a writeup on this in the "Discovery" section, see "basics"

Top of pagePrevious messageNext messageBottom of pageLink to this message   By DM on Sunday, March 18, 2001 - 10:11 am: Edit

OK...I read the article, and I understand now, but I still don't understand the positioning on the selector. For example....

I put it in the H position (down and to the right), and the vehicle moves.

If I put it in the N position (is this unlocked) center and to the right, the vehicle doesn't move.

If I put it in the L position (up and to the right) the vehicle moves, but in Low Gear.

I noticed that the control lever moves from left to right...what does this do?

I am trying to make sure I am in the "unlocked" position, but I still think I am doing something wrong, because in the N position, the Disco doesn't move.

HELP!!

Thanks!

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jay R. on Sunday, March 18, 2001 - 11:01 am: Edit

DM,

The Disco will NOT move in the N position. It should either be in H (normal driving) or L (offroad situations where low range is required). Lever will also move left/right which locks/unlocks the center diff.

High Range w/ center diff unlocked : Lever down & right. (normal driving)

High Range w/ center diff locked : Lever down & left. The diff lock indicator light will be on in the dash panel.

Low Range w/ center diff unlocked : Lever up & right.

Low Range w/ center diff locked: Lever up & left. Diff indicator light will be on in the dash panel.

In N, you should hear a warning tone. The vehicle will not move. This is normal.

Hope this helps.
Jay R.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry Crawford on Sunday, March 18, 2001 - 11:17 am: Edit

You aren't doing anything wrong DM. "N" simply means neutral - just like on a transmission shifter, when you are in neutral the transmission gears are out of mesh and no motive-power is being sent to the drive shafts.

Sort of think like the Disco has three transmissions, a main one we use all the time controlled by the shifting lever, and two others, one in the middle of each axle which we call "differentials" rather than transmissions. They are operated by the lever we are talking about. When the lever is in "N" no power is getting past the front and rear differentials to the wheels because you just commanded them to get into neutral. The transmission may still be meshed up and sending rotation to the drive shafts (also called output shafts), but, mechanically, the ends of the shafts are unlinked at the differential so you don't move. I guess it's sort of like when your bicycle chain slips off the rear sprocket - you can peddle like the dickends but no work gets done.

The "H" and "L" are only indications of the gear ratios you are selecting for the job at hand. Like if you are going to mix up some egg whites in a Kitchen Aid mixer, you don't need the lowest gear because your turning the blade through a light medium and controlled speed (the "H") is better, but if you are turning bread dough, a lower, slower, and more powerful gear ratio ("L") makes sense to push all of that heavy viscous stuff around.

I too had difficulty with the differential lock use, logic & methodology and I'm still not completly comfortable with it. But, I'll share what I do know and we can go on together into that dark night :-)

Anyone else like to review and comment on my explanation please do so, I'm an artist not an automotive engineer. Happy Rovering!

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Axel Haakonsen (Axel) on Sunday, March 18, 2001 - 10:31 pm: Edit

That's not quite right. The second lever has nothing to do with the differentials. It operates the transfer case, which sits behind the transmission. It is really a secondary transmission, if you will. The transfer case also has a differential in it, which is what you are locking when you move the second shifter over to the left. The differentials on the axles (on a stock Rover) are unlocked at all times. The purpose of locking the center differential is to distribute power equally to the front and rear axle when needed off road.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Axel Haakonsen (Axel) on Sunday, March 18, 2001 - 10:33 pm: Edit

The above should say: "The second lever has nothing to do with the differentials on the front and rear axle."

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Steve (Oz93discov8) on Monday, March 19, 2001 - 06:51 am: Edit

Hey Clint,

I've adjusted the diff lock indicating switch as you described in the "Tcase Trouble" posts and all is well. The diff lock is coming in & going out regularly (not always immediately but near enough). The switch was not all that tight so I suspect that over time it has lowered itself into the transfer case and interfered with the free movement of the diff lock mechanism.

Regular use of the diff lock is strongly recommended - if anyone is worried about diff "wind up" etc just find some dirt/gravel or any low grip surface and avoid tight turns. I sometimes just roll (straight) backwards & forwards in the carport locking the centre diff in & out to keep it in shape. Also stopping and backing up can "un-wind" the centre diff and help the light go out if it gets a bit sticky when unlocking.

It is worth listening for a slight "clink" in the transfer case when the diff lock comes in - usually in conjunction with the dash light - this confirms that it is actually locking up.

A Disco with a non-functioning centre diff lock is as good as useless when the going gets tough, especially if it doesn't have aftermarket front and/or rear axle diff locks.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Clint on Monday, March 19, 2001 - 08:25 am: Edit

That's great Steve-
I got a chance to try out my new lock in some slimy mud this weekend. The going wasn't that tough, but I felt better knowing that I had more traction back there. I went with my friend in his disco 2. We had just finished installing our prototype "down and dirty" diff lock kit on his truck. Anyhow, It got me thinking that the center gears aren't all that fragile (like some people say) as the disco 2 isn't equiped with a way to lock the diff.

To your point, even if you have a rear locker and the center diff is unlocked, you are no better off because the fronts will slip first.

Also, the first picture "tcase1" you sent was corrupt. Could you send it again?
Thanks,
Clint

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry Crawford on Monday, March 19, 2001 - 02:56 pm: Edit

Hey Axel - thanks for the straight scoop. As I mentioned I'm not much of a mechanic - but your exzplanation was good review for me. I thought the lever actually functioned on the differentials something like a limited slip. Many thanks & I hope readers will skip over my "mis-information" to yours.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Steve (Oz93discov8) on Tuesday, March 20, 2001 - 02:57 am: Edit

Clint I've found some even better details etc but need a bit of time to get them scanned etc (got a trip on very soon - it's our hunting season over here - and I'll be giving the diff-lock a workout in some sandy country!!). Get them off to you next week if that's OK.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By WVA (Vince) on Tuesday, March 20, 2001 - 11:01 am: Edit

I might be a little dense, but after reading all the above messages and twice going through the manual about trans and diff, I'm still cloudy as to what are the particular positions for? UNLOCK H is for normal driving. UNLOCK L is for off road driving. But I haven't read anywhere as to WHEN does one use LOCK L and LOCK H. Axel said the lock is distribute the power equally between the axels when going off road. Is there a "progression" in using these 4 positions? Like, unlock H is normal, unlock L is for a little rougher, lock H is still rougher,and lock L for really trying areas? thanks

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Rob Davison (Pokerob) on Tuesday, March 20, 2001 - 06:51 am: Edit

unlocked is for anything on road. usually you are in "unlock H" for this. there are a few situations that i can think of that you would want to be in "unlock L". maybe if you have a heavy trailer and you are going down a steep hill on dry pavement you would select this option. it would provide the benifet of low range engine braking while it is still safe to drive on pavement.

"locked H" is for general increase in traction where you might want to keep your speed up. like a snowy road.

"locked L" is for your out and out 4 wheelin'. or pulling someone out of a ditch or something where hi revs and slow speed are the ticket.

locking the diff simply makes you into a good old fashioned 4whd vehicle like an old trooper or blazer. unlocked is like an AWD vehicle.

PokeRob

Top of pagePrevious messageNext messageBottom of pageLink to this message   By nadim on Tuesday, March 20, 2001 - 07:19 am: Edit

UNLOCKED= at least one wheel is spinning
LOCKED= at least one rear, and one front are spinning

ihope you get my extensive explanations!

:)


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