Offroad-Express

im having problms with my lockright locker in the back of my HJ60,
it wont unlock. i did a days offroad and all went well. got to town and i noticed it squeeling round roundabouts. jacked it up and you cant spin just one wheel ether way.
iv changed the oil but the old oil looked ok not to metalically or anything. the locker has been in for 6 months.
whats wrong?

I've been caught thinking I had a problem recently, when actually I did not.

How did you check when wheels were in the air?

LockRights work by movement of ratcheting devices outwards in relation to the cross (4 sungear as in rear diff) or pin (2 sungear - front end).

These mechanisms are driven by the action of the pinion. Therefore to check the LR you must only jack up one wheel and then rotate the driveshaft.

I had both wheels in the air and thought I should be able to spin one wheel and hold the other. This sometimes will work but generally the LR will not disengage like this. Mine was locking only very intermittently and I thought I had problems. Soon afterwards the whole front end was apart due to an accident so I stripped the diff-head and found nothing wrong!

If your LR is not disengaging then the likely scenario is that the guide pins have broken. This happens when the ratcheting LR gears are not set up correctly (i.e. with too much clearance) When you have too much clearance the LR's bang and tend to make lots of clicking noises.
My experience is from a 4 pinion (rear) style LR set up in the front of my 71 series Prado.

Excess clearance means the LR specific ratcheting gears will ride up the cams more than designed for. When this happens they rotate a greater amount that allowed for by the slots created for the guide pins and the pins shear off, likely jamming the system.

The correct clearance seems to be between 0.004 to 0.006" (6 thousands of an inch) Worked out by a toolmaker who has set up many of these and done lots of back to back experiments. LockRight do not tell you the ideal shim setup. Shimming is often required because the Diff carrier inner faces tend to wear depending on how much spinning use they have had.

This distance has to be measured using at least two feeler gauges between the cross (or pin) and the LR ratchet gear-to-cross groove, whilst the cross is clamped into the other side, and the teeth are set so they are teeth to teeth rather than teeth to groove (i.e. minimum clearance) between the axle gear and the LR ratchet.
This measurement must be checked on both sides, i.e. both axle gears to both LR components.
In my case I chose to put in 10 thou (0.010") shim between the diff carrier inners faces and the axle gears to get the clearance back down to the correct 0.006". Due to the very low speed rotations here, now that you have a LR fitted, the stainless or brass shim stock that you can buy does not roll up or wear out.
My pins had shown no signs of wear but I wanted to get back to the best setup for release action and for durability.

It will have broken pins if it doesn't unlock

got another q for lock rights, how clancky are they suppoe to be in carparks or turning? i reverse out of a park then put the clutch in the whack wahck whack same with u turns i know they do it a bit but is there a level that u can tell its too tight? if it was would the extra loading damage my gearbox? its in the rear of my bj73 cruiser.

When I got my Lockright the instructions listed the clearance tollarence that would ensure the locker locked and unlocked correctly.

They also listed a 4 step test to ensure the locker is engaging and disengaging correctly. From memory... with both wheels jacked up off the ground hand turn the left wheel forwards (both will spin forwards) then stop the wheel you are holding from spinning and the opposite wheel should continue to spin forwards (and you should hear the clicking of the locker gears). Do the same again but spin the wheel backwards. Do this on both sides. If any of the 4 tests dont allow the opposite wheel to spin after stopping wheel in your hand your clearances are wrong or something is broken.

I am surprised to see the method of testing described as factory by you MNC.
As my post above, this tends to work only intermittently on the 4 pin models (my specific experience) due to the pins not being ramped out via the drive action of the pinion / CW.

My LR bought in 2004 had no shimming tolerance specs with it.

IcedJohnno wrote:I am surprised to see the method of testing described as factory by you MNC.
As my post above, this tends to work only intermittently on the 4 pin models (my specific experience) due to the pins not being ramped out via the drive action of the pinion / CW.

My LR bought in 2004 had no shimming tolerance specs with it.

If I can find the instructions it came with I'll scan and post it up. Is covered in oil but still readable.