WyKi Posted October 29, 2010 Share Posted October 29, 2010 Well thats the question....What are the ups and downs of LSD? On wet and dry surfaces.. as here in Puerto Rico we dont have snow or ice so.;. yea the most we get is rain and floods.. some Mud here and there when that happens. Most of the time it's hot and dry... unless you're in the forest and that's pretty much everywhere except the Metro area... And well mine isnt 4x4, only 2wd but yea.. should it work/be better if it were Posi-trac? Thanks. Link to comment Share on other sites More sharing options...
Precise1 Posted October 29, 2010 Share Posted October 29, 2010 LSD works quite well and in my opinion only has two draw backs compared to an open (1 wheel drive) differential. 1) With LSD you may have to be careful turning on slick surfaces at slow speeds. Not as much as a locker, but it can still spin you around. 2) You can't install a locker in the LSD carrier so to upgrade from LSD to locker you have to source an open 3rd member. A locker trumps LSD for effectiveness but has worse road manners and may promote faster tire wear. The LSD is adequate for most circumstances as it was designed and with the good articulation of the rear suspension it is less likely to lift a wheel and freespin. B Link to comment Share on other sites More sharing options...
MY1PATH Posted October 29, 2010 Share Posted October 29, 2010 B about covered it. If you do lift a rear wheel wit LSD sometimes pulling the e-brake puts enough resistance on the floating wheel that the grounded wheel still propels you instead of spinning the floating one madly. Link to comment Share on other sites More sharing options...
unccpathfinder Posted October 30, 2010 Share Posted October 30, 2010 A locker trumps LSD for effectiveness but has worse road manners and may promote faster tire wear. The LSD is adequate for most circumstances as it was designed and with the good articulation of the rear suspension it is less likely to lift a wheel and freespin. you can install lockers that allow you to select when your locked and open...I have an ARB which runs off of pneumatics to lock...i have seen mechanical electric and i'm sure someone does a hydraulic Link to comment Share on other sites More sharing options...
Precise1 Posted October 30, 2010 Share Posted October 30, 2010 Electric and hydraulic lockers for a wd21?? Maybe, but I have never heard of them. Yes, I forgot the ARB air locker, but I rarely consider a $1000 locker. Too rich for my blood... B Link to comment Share on other sites More sharing options...
unccpathfinder Posted November 1, 2010 Share Posted November 1, 2010 I never said for a WD21 specifically just stated that they are out there and if you SAS it you can run E-lockers from a D44 Link to comment Share on other sites More sharing options...
MrJim Posted November 3, 2010 Share Posted November 3, 2010 I will add my two cents here. I am installing a locker this weekend and I am pretty excited about it, but I have seen one major disadvantage to them. When on trails where your rig is leaning hard to one side as you are trying not to slide sideways into a rock or tree, LSD allows you to track forward while a locker can cause you to just drop sideways into the obstacle you are trying to avoid. Link to comment Share on other sites More sharing options...
unccpathfinder Posted November 7, 2010 Share Posted November 7, 2010 my buddy in his rubicon learned this last weekend...luckly he stopped about 1/2" from busting out his rear window...needless to say he couldn't get out check his position so I had to find a good winch angle and put 4x4's under his left tires to change the "roll" of the truck to keep him from getting the limb all the way down the side of his truck since he tried to back out and got back past the root...about 20 mins and I had him out and this was his first "oh @!*%" moment offroading... this is why i like the ARB b/c you can lock and unlock...i don't use it nearly as much as i thought i would...half the time i forget to lock it until i get stuck with free spin on all 4 corners Link to comment Share on other sites More sharing options...
OldSlowReliable Posted November 7, 2010 Share Posted November 7, 2010 My LSD is a dream....couldn't imagine anything different... However, my family has spun out the truck in winter because they are used to WJ's and things w.o lsd's and such Link to comment Share on other sites More sharing options...
mickyficky Posted November 9, 2010 Share Posted November 9, 2010 NO DO-NUTS with the LSD!!!! Not on pavement anyway. No really, LSD is awesome on the Pathy Link to comment Share on other sites More sharing options...
OldSlowReliable Posted November 9, 2010 Share Posted November 9, 2010 NO DO-NUTS with the LSD!!!! Not on pavement anyway. No really, LSD is awesome on the Pathy It does make snow-donuts alot more interesting! I can get spinnin pretty nice! Link to comment Share on other sites More sharing options...
MY1PATH Posted November 9, 2010 Share Posted November 9, 2010 NO DO-NUTS with the LSD!!!! Not on pavement anyway. No really, LSD is awesome on the Pathy I've done em, (wet pavement) just be real ready on the thottle because about the 3rd time you cross your own tire tracks it will grab and pitch you. So let off as soon as you start to feel it buck and find a new patch of pavement. Link to comment Share on other sites More sharing options...
sewebster Posted November 9, 2010 Share Posted November 9, 2010 Can someone explain this LSD spinning you out problem? I have one and am not familiar with it (probably because the truck has been mostly disabled in the garage since I bought it). Link to comment Share on other sites More sharing options...
OldSlowReliable Posted November 9, 2010 Share Posted November 9, 2010 Can someone explain this LSD spinning you out problem? I have one and am not familiar with it (probably because the truck has been mostly disabled in the garage since I bought it). In my experience, people who aren't used to driving with an lsd/locker will spin out easily (and even some people who know the truck) because they will be on a slick surface, and give it a little too much gas, making the lsd kick in and spin both wheels together, usually losing traction all together. Just a guess though Link to comment Share on other sites More sharing options...
Precise1 Posted November 9, 2010 Share Posted November 9, 2010 ^ Pretty much, but it usually happens when accelerating and cornering or accelerating on an off camber, slick surface. My 1 good spin was a left hand turn at a traffic light. Thankfully, it was a large intersection so I just looked like an idiot but didn't contact anyone/anything. Since then I have learned to moderate the throttle and let up the moment it acts like it may slip. B Link to comment Share on other sites More sharing options...
Kingman Posted November 9, 2010 Share Posted November 9, 2010 Yeah, you really can't drive a vehicle with a Posi or LSD in the rain the same as you would an open-diffed one. Hit the throttle around a wet corner like you would in the open, with the LSD, you'll be doing donuts. I usually have issues with freeway on ramps that are turned at the very entrance then slope up to the freeway. Giving it gas to accelerate always steps the rear out, though I have learned how to keep it to a minimum and not go entirely sideways. If you take corners nice and slowly in the wet, there shouldn't be much of a problem. There's sometimes the freak accident where it decides to step out anyways, which I did last night, with almost zero throttle applied going around the corner. Link to comment Share on other sites More sharing options...
Kingman Posted November 9, 2010 Share Posted November 9, 2010 NO DO-NUTS with the LSD!!!! Not on pavement anyway. No really, LSD is awesome on the Pathy Bull! http://www.youtube.com/watch?v=W7jfV4ohWh0 Link to comment Share on other sites More sharing options...
nismothunder Posted November 9, 2010 Share Posted November 9, 2010 lsd is fine,but its no replacement for ground clearance.It wouldnt matter if you had 454 with lockers frnt and back if your sitting on your frame. Ground clearance=better perfermance. Link to comment Share on other sites More sharing options...
ZombeeXXX Posted November 9, 2010 Share Posted November 9, 2010 Nice vid! One thing I've noticed (my first lsd rear drive) is the ability or tendency to slide the rears with engine braking. Only on a very slick surface, closing throttle abruptly can act as if you applied the parking brake. I haven't experienced any additional tendencies to oversteer on acceleration but before, I drove my Z year round and thus became very gentle with the gas. It is open rear ended but likes to wag its tail all over even on dry pavement a hard shift into second gets it loose. I feel the lsd pathy has always been easier to get a controlled sustainable drift in the snow. I suppose weight distribution comes into play. I have noticed lately pulling out from a stop or idle in first I can get some chirp out of the inside tire if turning and gassing it hard. I suppose it could be unsettling but it feels like I'd really have to stand on it to get it to break loose. Never really experienced any looseness in wet conditions but I guess I haven't really pushed it to see what it would do. Link to comment Share on other sites More sharing options...
sewebster Posted November 10, 2010 Share Posted November 10, 2010 So why does the LSD cause these problems? I guess it must be that to do that maneuvre you want, your wheels have to turn at significantly different speeds, so when the LSD doesn't allow that it "upsets the balance" and you go out of control (to some degree). Link to comment Share on other sites More sharing options...
Precise1 Posted November 10, 2010 Share Posted November 10, 2010 Limited Slip Differential is exactly that. It has clutch plates that bind up under load, until a certain point where there is enough torque to overcome the clutch friction and even then it will be a progressive slip. This is a good explanation... The clutch-type LSD is probably the most common version of the limited slip differential This type of LSD has all of the same components as an open differential, but it adds a spring pack and a set of clutches. Some of these have a cone clutch that is just like the synchronizers in a manual transmission. The spring pack pushes the side gears against the clutches, which are attached to the cage. Both side gears spin with the cage when both wheels are moving at the same speed, and the clutches aren't really needed -- the only time the clutches step in is when something happens to make one wheel spin faster than the other, as in a turn. The clutches fight this behavior, wanting both wheels to go the same speed. If one wheel wants to spin faster than the other, it must first overpower the clutch. The stiffness of the springs combined with the friction of the clutch determine how much torque it takes to overpower it. http://auto.howstuffworks.com/differential.htm B Link to comment Share on other sites More sharing options...
sewebster Posted November 10, 2010 Share Posted November 10, 2010 Right, I think I get the idea of the LSD, just not why that causes you to spin out. Same as why a locker might cause you to spin out I guess (don't understand that either). Never even driven a RWD car before. Link to comment Share on other sites More sharing options...
Precise1 Posted November 10, 2010 Share Posted November 10, 2010 Never even driven a RWD car before. The core of the problem!! If both wheels spin at the same rate, the car can't turn correctly, it has to slip. If one wheel slips while cornering with poor traction while accelerating, they will generally both start to slip together. You now have a rear axle that is sliding not rolling. Add steering in the other axle/end of the vehicle and the slide can go any direction, although is sometimes steerable... B Link to comment Share on other sites More sharing options...
MY1PATH Posted November 10, 2010 Share Posted November 10, 2010 Ok lets start with why and open does not cause you to spin; when you loose traction on an open the wheel that has the most traction stops turning and the wheel that has the least spins feely at nearly double its original speed. In a turn this free spin causes the vehcle to slow down untill both tires have equal traction. In a straight line the same thing happens. Ok Now imagine the opposite For LSD's and Lockers, Imagine a RIG with just one wheel in the back. Since that one wheel is off to one side its gonna push the vehicle off to one side. Now even tho the other wheel is still there it doesn't do anything to counter-act this force becasue it has no traction. In a turn this side push can do 2 things; follow the vehcles momentem and put you into a spin push the opposite way and cause an understeer. or in rare cases a counter-spin In a straight line the effect of the the direction is fairly random, you may just go a straight line or it may buck/spin to the left or right. In both cases the situation only contiunes to unravel if the traction wheel is allowed to break loose because now you have 2 wheels that are spining and not counteracting any of the momentum you already have. Easy solutions; when in a turn on wet roads or other low-traction surfaces if you notice any type of over steer or understeer ease off of the gas. if you know its slipery make a habbit of breaking before the turn and coasting thru the turn aplying power only after your vehicle has straigtened out. ease off the gas anytime you feel like you may be losing control but don't be too quick to break either. Make your steering corrections sublte and slow because when both wheels are spinning your stering can over-react to your input. Don't floor it arround corners. Learning; (and this is good for any vehicle thats new to you) go to an empty lot, acelerate hard, brake hard turn hard. this is not about pusing the vehicles limits, this about learing how it handles normally when you need to do one of those things on the road with people arround. Now go back on a rainy day, on a snow day etc and do the same. Again this is not about pushing the limits this is about learning how to be safe so DO NOT get caried away. Note the differances, and practice the tips above for overcoming the handling issues that arrise on the rainy lot. Only engage your locker when you need it. Link to comment Share on other sites More sharing options...
sewebster Posted November 10, 2010 Share Posted November 10, 2010 I think I get it now, thanks! Link to comment Share on other sites More sharing options...
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