Re:Deciding on a Diff for a Daily Driver

I've got a bit of a conundrum here:

My jimny is my only car and it does everything. Off road wise, that means trials, and a multi day on and off road navigational challenge. 
It went in for it's mot recently, and the tester noted that the back diff was making a noise. Not great. I jacked it up and checked, and found the noise is coming from the spider gears (? the ones that let the wheels spin a different speeds), so this is an opportunity to put in something more useful offroad. I don't know if there are any garages near my that would do it, but I watched Martins video of him installing an air locker and based on that, I can do the work myself if I get the indicator thingy. 

As far as I can see, the options are:

ARB air lockers, while I have no doubts they're good, they're too expensive for me, and I don't know where I'd put the air system. 

Quaife ATB, on the expensive side again, but I can probably afford it if it's worth it. Great on the road, and should be reliable, but from what I've read on here, they don't actually lock, and don't help if I've got a wheel in the air. 

Chinese E locker, could be good. The expensive ones seem to be getting close to the cost of a Quaife, but the cheaper ones are closer to a lunchbox. Apparently they unlock for a moment as you change direction and I've seen a thread on here where it didn't actually fit.

Lunchbox, cheap and cheerful, and apparently excellent offroad, but I've seen mixed reports on their on road manners.

Standard diff, cheap, but boring. Easiest if I can find a correct fully assembled unit, but I understand there's a few different ratios, and I don't think there's a correct one going on ebay at the moment.

Any thoughts or comments would be appreciated. What one would you get in this situation?

Personal preference definitely but I would have a atb quaife in a heart beat. Yes it doesn't lock but a dab of foot or hand brake to get some resistance and the wheel in the air doesn't matter anymore.

This sort of diff. will obtain approx. 90% lockup.

Roger

considering the amount of work or cost if you have to hire someone to install it, I would go for the ARB and do it once. It is the best both on and off road and the best quality. As yours,  mine is also a daily driver and used for long trips during the summer.
I could afford the ARB just because my friends and collegues chipped in for my 40th birthday present. My second one (for the SJ) I saved up for, sold parts and managed to trick money away on my hidden Suzuki account in a swedish bank so my wife won't find it (just kidding, she knows.)
And when it was bought the NOK against USD was favourable. If i had less to spend, I would be on the hunt for a used one instead I guess. Remember that in the rear also a RD88 from a samurai will fit nicely. Mine does.

This maybe of interest. Being American the naming convention is different, but you can still figure out which is which.



Looks like the subject in general could open a can of worms, it's open to personal needs and expectations.

Personally, if your goal is day to day road use with perfect off road control I would save your cash and fit an ARB air locker....
I am assuming the Chinese electric lockers are rubbish, possibly unfair, but not seen any long term use reports so not even considering.

Running second is the Quaife ATB. Not quite as good in the mud, but unlikely to cause any road issues and generally just make things better than an open diff.

Of course just my opinion, but full locker off road (by air or by e) for me.



 

By the way, my ARB was also put in when my diff failed. Most likely because I been pulling trailers alot, got the M16A, 235's and a heavy foot.
My diff made a tiny bit of noise for about 10 seconds of driving before the pinion lost a few teeth in a horrible sound as I accelerated out from my driveway.
Just barely managed to crawl and limp back to my garage.

I think the earlier models has better lower stronger ratio in the diffs, 3.9 or yours 2004 has 4.09.
Mine is 2005 with 4.3 ratio so more "force" transmitted in the diffs.
But then again if you plan on doing larger tires you could see if swapping to the 05 or newer diffs could be suitable for your tire size.
check a gear calculator if you consider this.