issue with difflock not engaging after diff change on jtop

[jonnyjtop]

hey guys and gals iv got an issue again so here is the story i snapped an axle a while back and i just got around to changing it just now at the same time we realised i stuffed the diff so i got another center and installed everything it all works all good... anyway i went to engage the diff lock and noticed the compressor did not go for as long as usual and it does not lock so in other words it starts to lock but then does not lock before i remenber a constant compressor sound for about 1-2 seconds then it would lock into place but now its more like a quarter of a second and does nothing the light doesnt even turn on (the light does work) i already have the compressor hooked up to a switch with permanent power and the compressor is and was working fine....i dont get it?????

any ideas???

[wangapajero]

Dont know about the specifics, but might I suggest, and I dont mean to sound condecending at all), sit back and double check all connections; electrical and mechanical including the lines to the diff), follow the whole run through first; ifg that looks ok, i'd disconnect the air line at the diff and check the compressor runs constantly when you try and engage. Once youve proved this, it will give you a steer which end the problem might lie; you might find the compressor has partially siezed if its been sitting a while?

[jonnyjtop]

yep iv tried all that took off the line and sucked continuasly the old one still worked as i could only get the car to move with it enguaged....

also to my surprize the compressor sucks not blows...

[Bitsamissin]

Sounds like the compressor is wired in reverse somehow.
If it is all good then disconnected at the diff it will stay on all the time as the air line will never pressurise and trip the pressure solenoid.

[hudson44]

Yeah, i would do what Frank said. Pull the line off the diff and see if the compressor runs flat out. If it does then the diff lock actuator (do they run similair to ARB diff lock frank?) must be stuck. If its not pumping air and the pressure switch is cutting it out, then you will have a blockage in the line to the diff. The reason it is running for less time is because there is not as much volume to fill due to a blockage etc for the pressure to build up to the switch pressure.

Are you sure it's sucking? They only run about 5 psi.

[Bitsamissin]

Yes they are VERY similar.
So much so that ARB were very close to taking the Japanese co that makes them to court for patent breaches but decided not to (the last I heard). The same air lockers are found in some limited edition Jeeps and lots of trucks.

[jonnyjtop]

sorry my mistake it is blowing it was late last night when i checked it out quickly.... but tonight i found out why the compressor was runing for less time turns out the banjo that supplys the air to the diff was blocked so i put the one from the old diff and now it runs air perfectly...but now still a problem it doesent lock it nearly grabs but doesent im going to have to pull out the diff all over again....its definately not the compressor because i hooked up the line to my old diff on the floor and it locked in perfect.....this unit must be stuffed somehow (it still has all its teeth ect)im going to pull it all out again to investigate further and just take it back where i got it and replace again he had a few on te shelf...it is really annoying now

also in addition to this when i take off the hose the compressor does run flat out without stopping....but when i block it with my finger it stopps it works as it should.... i think.......

[hudson44]

Can you use the actuator from the original diff centre? Are they bolt on? Comp sounds like its working fine.

[jonnyjtop]

yeah i could but why should i have too...its got a guarantee so ill just take it back to the wrecker and let him give me another one he was very helpful so far so ill see how it goes.........thanks for the imput so far and ill let you all know how it goes

[jonnyjtop]

turns out the locking teeth all snapped off into the diff somehow.....my mecchanic should have inspected the unit before he installed it all.....any way all good now guys went bback and the wrecker replaced it all no worries.......thanks for all the advice guys