Thread: Diff locks

Originally Posted by jik22

Is this a complete set, front and back, with the mentioned driveshafts, etc.? I thought the ARB ones were $3k, so that doesn't sound too bad if you are getting extra bits too

No, 3k from ARB is just the locker and nothing else. There might not be a compressor in that either

Originally Posted by jik22

There's abeen a few threads on here over the last few months re lockers. Just wondered what were the pros and cons of the different types?

So far, I have come across the famous ARB air lockers and the maxis which look like they're engaged by an electrical solenoid - so, what are the advantages/disadvantages of air vs solenoid engagement?

Also, I've seen mention of Detroit who seem to do an LSD for the back and something else I can't remember the name of for the front. Now, from my time spent playing with street cars, LSD's were great on the road, but still slipped at some point to enable cornering...so why would people use these in preference to locking the diff solid when off-road?

How would you decide what type best suited?

Oh, and if and when I go to the expense of fitting something like this, should any other parts of the drivetrain like CV's or drive shafts get uprated in any way or just checked and left alone to be replaced with factory parts when necessary?

I have ARB lockers front and rear in my 93 Disco, it also has Maxi-Drive axles and Flanges all round, the CV's are from a Defender. They are operated by compressed air from an ARB compressor under the bonnet, they do have a problem with an "O" ring in the locking mechanism leaking, causing diff oil to be sucked back up the air line to the compressor, mine has this oil problem on the rear diff. It was suggested by a mate to check the diff breather and make sure it wasn't blocked, it was, since clearing this blockage I haven't had any more diff oil in the compressor air line. I also have 4.11:1 gearing and run 33" muddies. I think if you are going to fit ARB or Maxi-Drive selectable Diff Locks (Maxi-Drive come with their own axles and flanges as part of the Kit), then you should beef up the entire driveline. I beleive that all 4wd's should have these diff locks it makes 4wdriving so much better, I wouldn't own a 4wd without them, they are so good, Regards Frank.

Originally Posted by rick130

Firstly, Detroit Lockers and Tru Tracs used to be made by a company called Tractech, now been swallowed up by Eaton in the US.

Secondly, a Detroit Locker is a pair of dog clutches splined to smaller hubs which are splined to the axles, with a central dog ring connected to the diff case. This locks the two outer dog faces together, not sprags. On differential wheel speed an outer dog ring can be forced against spring pressure to unlock, giving differential action. As soon as both wheels are rotating at equal speeds, the springs force the dogs to re-engage, locking the diff.

A sprag clutch is a different animal altogether, and will unlock on the over-run, and I'm assuming in reverse.
A famous locking race diff from the seventies was the Wiseman (sp?) Locker that was basically a sprag clutch and cone. It locked 100% but unlocked on the over-run, which is important in a race car as it doesn't then cause corner entry understeer. A Detroit Locker remains locked as you describe, causing corner entry understeer (as does a spool) and only unlocks under differential wheel speed.

A Detroit Locker or No Spin locks the same forward or reverse.

Good explanation - thanks for that.

Originally Posted by jik22

Is this a complete set, front and back, with the mentioned driveshafts, etc.? I thought the ARB ones were $3k, so that doesn't sound too bad if you are getting extra bits too

No rear only, around the same again for the front, maybe a tad less as no drive shaft or flange required

Originally Posted by Captain_Rightfoot

No, 3k from ARB is just the locker and nothing else. There might not be a compressor in that either

Around $1300 for a rear ARB locker complete for the D2 ABS type, + $620 for Maxi axles, so around $4000 F & R

Baz.

Originally Posted by Redback

No rear only, around the same again for the front, maybe a tad less as no drive shaft or flange required

Around $1300 for a rear ARB locker complete for the D2 ABS type, + $620 for Maxi axles, so around $4000 F & R

Baz.

'kin hell! Lucky my driving is nowhere near up to tackling places where I'll need 'em yet then!

I think on cost alone it would have to be the ARB's when I do need them...

Your other option is Detroit rear and Tru-trac front, there are a couple of guys on here with this setup, Discowhite in his Def 90 and stevo in his D2.

I think it's around $900 for the Tru-Trac and $1100 for the Detroit.

+ axles of coarse

Originally Posted by Slunnie

Are you sure that Detroits don't lock in reverse? Thats the first time I've heard this.

That's because its not true

Originally Posted by djam1

Detroit lockers do lock in reverse, well mine does anyway.
In fact you can reverse them when you pull the diff down and double their life span.

OOOOOOOkay, How does the crown sit in the correct position once reversed