by wombat200 on Tue, 30 Jul 2013 3:36 +0000
Ok, Detroit vs ARB vs Eaton.
I've had a number of vehicles with a Detroit locker in the rear. There pros & cons with each, but personally I think the Detroit is better for most users in a REAR fitment. I am not a hard-core off roader, more a tourer, and certainly mostly a week-end warrior, using my cars for commuting in Melbourne.
Most vehicles today come with a rear LSD. This is a good thing & provides good traction on road, or on slippery surfaces where most people would not want to use 4WD. A manual locker is a backwards step here, as you lose all LSD function in the rear. Given that most vehicles are driven on-road for the bulk of their use, this is not useful. I like to think of my Detroit as a really positive / aggressive LSD.
An ARB locker requires three systems to be functioning - mechanical (the gears/diff) electrical (to run the compressor) and pneumatic (to actuate the diff). The mechanical part never fails, but the other two can. A ripped out air line, or worse, a failed compressor, will see you back to an open diff, possibly with no way to repair it. The eaton is better in this regard - just a twin-core wire that could be repaired easily, for the most part - but the Detroit is purely mechanical, with a good record in reliability.
The Detroit will get you through most obstacles before you even realise you needed it, whereas a manual locker requires a degree of decision-making. Make the wrong one & you may lose momentum, or end up in a situation that may be difficult to recover from. Usually not a big deal, but it's one more thing to think about. Some guys say "I like to have the control" but getting stuck in something because you didn't think you needed to lock in isn't a great look either.
There is some impact on driveability, but not as much as most people think. In a large wagon, it's almost imperceptible - more felt through your backside than through the steering wheel. It is at it's worst at very slow, full-lock maneuvers - IE car parks, etc. At speed on bitumen, it's essentially not a problem. It is important to keep tyre pressures equal on the axel, and always run with same diameter tyres. The longer the wheel-base, the less you feel it, with a slight exception - the light rear of an unladen ute can also exacerbate it, but dual-cabs utes with a canopy, drawers, etc, are good. As I said, I commute with them, it's simply not a problem.
The ARB locker was a great invention, and is still a great product, but at the time it emerged, the Detroit was a fairly crude device, with harsh lock/unlock characteristics. There have been a number of improvements to driveability of the Detroit, and the versions from ~ 15 years ago onwards are very easy to live with.
I honestly believe the benefits of a Detroit FAR outweigh the cons of an ARB locker - losing the LSD function is a big loss for a vehicle that is mostly used on road.
For a front fitment, the situation is very much reversed & I prefer a manual locker up front, but that's for a separate post........