posi
#1
07-19-2010, 09:38 PM
#2
07-20-2010, 08:34 AM
I recommend a selectable locker for the front axle. Any other locker up front (except True-Track) will be impossible to steer for the most part. You want to be able to lock in the front end when needed and unlock for steering all the rest of the time.
Out back, there are a number of good choices, from selectables, to drop-ins, to detroits. Depends on the size of your wallet and the amount of weight you wish to transfer.
If you are just dealing with the truck itself (as in wanting extra traction for snow or mud, but not with a load) any of the drop-in lockers (also called "lunch box" lockers) will work great in the rear axle. Name brands are Aussie, Lock-Right, EZ Locker, etc. They'll also work up front, except for the steering issue noted above (lockers make stuff go straight ahead). These type lockers replace the factory spider gears with a new unit, and can be installed without setting up the ring and pinion gears. Typically, the install can happen in your driveway in a couple of hours. Just open the axle cover, drain the oil, flush out any crud, slide out the axle shafts, remove the cross-pin and remove the spider gears, then replace all that with the drop-in locker and re-fill.
A Detroit locker or a selectable locker requires replacement of the entire carrier, which also requires setting up the ring and pinion again. That sounds like a lot of work, and it is, but if your needs also include towing or hauling heavy loads while locked then this type is the better choice as the strength is much improved over the drop in units. You will want to be aware of certain factors such as gear ratio ranges -- most carriers are designed for a certain gear ratio (4.10, 3.73, etc.) and they only fit certain ranges due to the thickness of the ring gears. You will also want to replace the carrier and pinion bearings while you have the axles apart this far, so add the cost of an install kit to the price of the locker.
Selectable lockers let you chose if you want to be locked or open by some means, mechanical (True-track) electrical (e-locker, e-trax) or air (ARB). Each has their own good or bad points. the True-Track is a good locker for a steering axle if you want something that doesn't require air or electric lines. A simple tap on the brakes will slide a gear into place and allow both tires to pull at the same time. They are not best for heavy loads, however, as the gears will eventually wear out and start slipping. ARB air lockers are probably the state of the art in the industry, and are proven solid performers, but you also have to understand that once locked in they are a spool -- both sides of the axle are locked -- period. That is great for traction, again, not great for steering. Most off-road guys end up with hydro-assist to steer that sort of locker.
Another option is the limited slip type carrier, which uses clutch plates or a cone clutch to transfer power to the spinning tire. These are good for street use, not so good for towing or off-road use where you need traction on one tire to carry the total load of the truck. What you are calling "posi" (a slang term for positraction, one corporation's version of a clutch-type limited slip) are these. They were popular with the muscle car people, not so popular with the truck crowd, as they are limited in ability to transfer weight under load. They too will cause steering issues in the front axle when in 4x4.
One other thing to bear in mind -- lockers (any of the ones above) under certain conditions actually reduce traction in unexpected ways. Slippery roads, for instance, can cause problems, especially with street driving. With an open carrier in the rear axle, the truck will generally go straight forward, even if one tire is spinning, because the other tire is standing in place halting side-slipping. Once you spin both tires, the truck will come around very quickly, often surprising the unaware driver and causing problems in traffic, especially at stop lights where you may be sitting 3 deep and 3 wide and there is no room to get sideways. This is another reason I so favor selectable lockers.
I can give more advice, but I'll need to know your purpose and your budget.
Out back, there are a number of good choices, from selectables, to drop-ins, to detroits. Depends on the size of your wallet and the amount of weight you wish to transfer.
If you are just dealing with the truck itself (as in wanting extra traction for snow or mud, but not with a load) any of the drop-in lockers (also called "lunch box" lockers) will work great in the rear axle. Name brands are Aussie, Lock-Right, EZ Locker, etc. They'll also work up front, except for the steering issue noted above (lockers make stuff go straight ahead). These type lockers replace the factory spider gears with a new unit, and can be installed without setting up the ring and pinion gears. Typically, the install can happen in your driveway in a couple of hours. Just open the axle cover, drain the oil, flush out any crud, slide out the axle shafts, remove the cross-pin and remove the spider gears, then replace all that with the drop-in locker and re-fill.
A Detroit locker or a selectable locker requires replacement of the entire carrier, which also requires setting up the ring and pinion again. That sounds like a lot of work, and it is, but if your needs also include towing or hauling heavy loads while locked then this type is the better choice as the strength is much improved over the drop in units. You will want to be aware of certain factors such as gear ratio ranges -- most carriers are designed for a certain gear ratio (4.10, 3.73, etc.) and they only fit certain ranges due to the thickness of the ring gears. You will also want to replace the carrier and pinion bearings while you have the axles apart this far, so add the cost of an install kit to the price of the locker.
Selectable lockers let you chose if you want to be locked or open by some means, mechanical (True-track) electrical (e-locker, e-trax) or air (ARB). Each has their own good or bad points. the True-Track is a good locker for a steering axle if you want something that doesn't require air or electric lines. A simple tap on the brakes will slide a gear into place and allow both tires to pull at the same time. They are not best for heavy loads, however, as the gears will eventually wear out and start slipping. ARB air lockers are probably the state of the art in the industry, and are proven solid performers, but you also have to understand that once locked in they are a spool -- both sides of the axle are locked -- period. That is great for traction, again, not great for steering. Most off-road guys end up with hydro-assist to steer that sort of locker.
Another option is the limited slip type carrier, which uses clutch plates or a cone clutch to transfer power to the spinning tire. These are good for street use, not so good for towing or off-road use where you need traction on one tire to carry the total load of the truck. What you are calling "posi" (a slang term for positraction, one corporation's version of a clutch-type limited slip) are these. They were popular with the muscle car people, not so popular with the truck crowd, as they are limited in ability to transfer weight under load. They too will cause steering issues in the front axle when in 4x4.
One other thing to bear in mind -- lockers (any of the ones above) under certain conditions actually reduce traction in unexpected ways. Slippery roads, for instance, can cause problems, especially with street driving. With an open carrier in the rear axle, the truck will generally go straight forward, even if one tire is spinning, because the other tire is standing in place halting side-slipping. Once you spin both tires, the truck will come around very quickly, often surprising the unaware driver and causing problems in traffic, especially at stop lights where you may be sitting 3 deep and 3 wide and there is no room to get sideways. This is another reason I so favor selectable lockers.
I can give more advice, but I'll need to know your purpose and your budget.
Last edited by glfredrick; 07-20-2010 at 08:40 AM.
The following 2 users liked this post by glfredrick:
The_Head (07-20-2010),
tiremann9669 (09-09-2010)
#4
09-09-2010, 05:22 PM
#5
09-09-2010, 05:58 PM
One other thing to bear in mind -- lockers (any of the ones above) under certain conditions actually reduce traction in unexpected ways. Slippery roads, for instance, can cause problems, especially with street driving. With an open carrier in the rear axle, the truck will generally go straight forward, even if one tire is spinning, because the other tire is standing in place halting side-slipping. Once you spin both tires, the truck will come around very quickly, often surprising the unaware driver and causing problems in traffic, especially at stop lights where you may be sitting 3 deep and 3 wide and there is no room to get sideways. This is another reason I so favor selectable lockers.
I can give more advice, but I'll need to know your purpose and your budget.
I can give more advice, but I'll need to know your purpose and your budget.
