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Post by jasin on Jul 10, 2015 4:43:27 GMT -5
Hi there, since some time I'm riding Justy with RWD. There is a big problem with traction, especially on the wet surface. I've deciced to build LSD in original justy's diff. it is much more then phantom grip. It is a kind of simple plate LSD but without ramps. Gear wheals are ititially forces by springs and in case of big torque from the engine separation force is naturaly much higher. Gear wheels are milled and have special friction plates attached. Friction plates make a friction between gear wheels and diff case. there are only two plates - each at the one side. They are not visible at the pictures, but believe me - they are there I put new bearings and sealings and used LSD Castrol oil. I put it all togerher into car 2 days ago and works great. During normal conditions, with calm driving on a dry surface it is like an open diff, but when you drive at full power it locks so works just like it suppose to during the rain with RWD it drifts like hell Hope it will not break very soon, but by now it's really fun.
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Post by southerner on Jul 10, 2015 21:50:42 GMT -5
Not really sure what you did there.. could be my poor english, my poor mechanic skills or both.. you mean that you can have 4wd engaged full time but it'll lock by itself if traction is lost ? how would that work on icy tarmac for example ?
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Post by jasin on Jul 11, 2015 0:17:24 GMT -5
First of all my justy is not RWD not 4WD. I did rebuild real diff changing it into lsd-limited slip differential. Works as usual diff while crusing, and locks at WOT. Locks means both axles rotates with the same speed. As in Sport cars. That makus justy a drift machine, when pedal is pushed till the end.
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Post by southerner on Jul 11, 2015 10:17:26 GMT -5
I see.. im gonna wait for you to explain in detail what you did and how much it lasts..
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Post by Deleted on Jul 11, 2015 12:21:57 GMT -5
First of all my justy is not RWD not 4WD. I did rebuild real diff changing it into lsd-limited slip differential. Works as usual diff while crusing, and locks at WOT. Locks means both axles rotates with the same speed. As in Sport cars. That makus justy a drift machine, when pedal is pushed till the end. In the US we call those auto-lockers. They're different than an LSD.
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Post by jasin on Jul 11, 2015 12:38:38 GMT -5
My technical English is not SO good good to know
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Post by jasin on Jul 11, 2015 12:52:59 GMT -5
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Post by southerner on Jul 11, 2015 18:37:40 GMT -5
First of all my justy is not RWD not 4WD. I did rebuild real diff changing it into lsd-limited slip differential. Works as usual diff while crusing, and locks at WOT. Locks means both axles rotates with the same speed. As in Sport cars. That makus justy a drift machine, when pedal is pushed till the end. In the US we call those auto-lockers. They're different than an LSD. Hi @ferox.. could you shed some light on this ? could it have a practical application on a daily driver ? BTW, just did your thing on the tailights.. they look awesome..
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Post by Deleted on Jul 12, 2015 13:55:02 GMT -5
Ok so I am not picking on you jasin, but your statements contradict each other. I know english isn't your first language, so let's clarify. If both wheels lock and turn at the same speed, as you have stated, that's called a locking differential. It's typically used for off-roading and rock-crawling. Typically lower speed applications, where one wheel may be in the air for critical maneuvers. If the differential transfers power back and forth to the wheel with the most traction, that is an LSD, described in the simplest terms. They are used for snow, rally, mud, and any other low traction, higher speed applications. They are also great for low-speed, but not typically in a situation where one wheel is in the air. I think it's safe to say that we are all very interested in what you have built, so don't take this as criticism. A rear LSD for a Justy would probably be about the coolest thing ever done on a Justy in my opinion. If it breaks traction in the rain that sounds more like an auto-locker, but we would definitely like to hear more about it.
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Post by Deleted on Jul 12, 2015 14:19:49 GMT -5
In the US we call those auto-lockers. They're different than an LSD. Hi @ferox.. could you shed some light on this ? could it have a practical application on a daily driver ? BTW, just did your thing on the tailights.. they look awesome.. For a daily driver, a rear lsd would be great, an auto-locker, maybe not so much. You won't notice a difference driving with a rear LSD vs. open diff in normal driving conditions, and in low-traction situations you would just have more traction unless you get one wheel in the air. Most LSD systems require a little resistance on the slipping wheel to transfer power to the traction wheel, hence one reason people install split hand brakes to individual rear wheels. With an auto-locker you might not notice much during normal driving conditions either. It depends on how sensitive it is to locking. The biggest issue with the auto-locker is that if it engages in a corner it will want to push you straight rather than turning because both rear wheels are turning at the same speed. This can happen on rainy roads unexpectedly if you are not familiar with the unit and can result in either pushing you straight or breaking traction and fish-tailing like crazy or a combination of both. In snow the biggest issue is that it will just push you straight through corners, but it can also lock and unlock a lot giving unpredictable behavior. So an auto-locker is definitely not recommended for snow. In a Justy, I think most people would benefit from an LSD. If you are building a rockcrawler Justy then an auto-locker might be good, but that would be more appropriate for a dedicated off-road rig that you would haul to the trailhead on a trailer. If I weren't selling my Jeep I would probably install Eaton electronic selectable lockers front and back. They are an LSD when not engaged, but can be locked with the push of a button or flip of a switch from the comfort of the driver's seat. Not cheap and probably not what you would want in a dedicated wheeler, but perfect and effective for my needs.
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Post by southerner on Jul 12, 2015 14:36:48 GMT -5
I see.. i thought it could be some sort of full time AWD thanks a lot for clarifying ! BTW, is that correct ? clarify/clarifying ?
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Post by bizarro on Jul 12, 2015 17:31:32 GMT -5
Awd....makes me think of the ones who sell a Justy "with AWD!!!" at 2,500 a pop.
LSD......thank goodness for Gran Turismo
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Post by jasin on Jul 13, 2015 6:52:09 GMT -5
OK, so mine solution is definetly LSD, not a locking differential. you are right, my discription was much to simplified It works completly the same as in this movie: www.youtube.com/watch?v=WeLm7wHvdxQ&feature=youtu.beI am not able to explain it more clearly than in the movie so it is a differential which has a limited slip between side gears (in fact axles) and diff case (in fact shaft) side gears are milled a little and has friction discs attached (sticked), in my case there is only one friction disc at each side. As seen in the movie (2:55) Fsep push side gears to the diff case which through friction discs makes a friction and in fact transfer more torque to axle I don't know how to explain it more clearly If you don't understand something please ask, I will do my best to explain anyway there is a nice result: during normal driving condition it behaves as a normal differential, during fast start on slippery surface (ie wet termac) the torque is transfered to both wheels (not only one as in the open diff) so it resaults much smaller skid (?). The same on the narrow turns (in open diff the inner wheel which is less loaded lost traction). Of course if you push gas pedal to hard you can make a slide and the car is surprisingly easy to drive in the slide in Europe LSDs ar quite popular in RWD cars (specially BMWs), but also some FWDs have it. Attachments:
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Post by Armageddous on Jul 13, 2015 15:03:07 GMT -5
I am really impressed by this.
Do you have a parts list or specifications to publicize?
Terry
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Post by southerner on Jul 13, 2015 15:38:33 GMT -5
I was about to ask for a thread on how he did this.. i'm really curious..
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Post by sp0ngebob on Jul 13, 2015 15:51:25 GMT -5
This is interesting as its a combination of a phantom grip type that just puts pressure on the spider gears to dry and put a simulated "load" on them to create friction to help drive them and a clutch type lsd.
FEROX: what you were talking about is also commonly called a "1 way" or "2 way" LSD. a 1 way locks under acceleration and a 2 way locks under acceleration and deceleration. theres also a 1.5 way but thats a litle strange device. Ive also never heard this called an "Auto Locker" before and ive never seen one that was only at WOT vs just some force that would accelerate or decelerate the car.
Maybe this is my knowledge of diffs, but how does the friction plate help? i get it that the housing rotates and turns the "top and bottom" gears which turn the spider gears but arent those fixed to the output shafts? so i dont see the need for those friction plates unless you just had a bunch of slack/clearance in the gears and needed to snug them up.
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Post by jasin on Jul 14, 2015 1:04:11 GMT -5
I'll leave the principleas of how it works for google, surely u can find tons of info about lsd regarding my modifiction: unfortunattely i dont have any drawings, as it was only a prototype and i wasnt sure it will work well, I know its not proffesional attitude, but im not professional have a look at that picure: www.dustysjustys.com/IPL/JFIG190-2.jpgnr 8 - spacers were removed nr 9 - side gears or spider gears (however its called) were milled (rolled on lathe) as far as i remmember exactly 1mm on the surface marked on the foto, then Ive sent them to a company producing special clutches for machines, they put a friction disc on that surface and somehow sticked it to the gears. Thickness of discs is 1.8mm each. The material which discs has been made is a special material which is ment to work in oil and ive been told usual thickness of such discs should be somwhere between 0.5 and 2 mm, so mine 1.8mm suits just right. Number 1.8 comes from the thickness of the removed spacer (0.8mm) and milled (rolled) surface on the gear (1.0mm). nr 36 - shafts-axles - normally they are long enough to touch pinion nr 5, so they had to be shortened not to be longer then side gears nr 10 rings were removed due to shortening of shafts-axles; now shafts are not secured against removing from the diff case, so ive to be carefull during any works around rear susspension not to remove the axle form diff between the sidegears there are special plates and springs - see the drawing (sorry for it), springs should be as hard as possible - mine are from the big clutch of some truck. Plates should be done in a way to stand as still as possible between the gears and pinion but not to disable them rotating everything put together and more or less that's all sorry for distances in mm, I now most of u use inches
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Post by sp0ngebob on Jul 14, 2015 10:31:54 GMT -5
not trying to knock it. I think this is mega cool that you had the balls to go do this.
However i still dont see the need for the "friction disc" but that may be a misnomer, or the wrong word. the spider gears dont spin on the axle stub shafts. they are driven 1:1 with the axles. so maybe that was to improve or reduce clearance between the housing gears and the spider gears? a pretty easy solution if you had a little play in there that needed to come out.
wicked cool build. your drawing is exactly a phantom grip btw.
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Post by Deleted on Jul 14, 2015 12:50:42 GMT -5
FEROX: what you were talking about is also commonly called a "1 way" or "2 way" LSD. a 1 way locks under acceleration and a 2 way locks under acceleration and deceleration. theres also a 1.5 way but thats a litle strange device. Ive also never heard this called an "Auto Locker" before and ive never seen one that was only at WOT vs just some force that would accelerate or decelerate the car. That's not what I'm talking about, and I didn't ask. If you have never heard of an auto-locking differential just do an internet search.
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Post by sp0ngebob on Jul 14, 2015 14:17:19 GMT -5
wow. way to be a bitch. ok.
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