kj280z Posted January 6, 2009 Share Posted January 6, 2009 I suppose this falls into the OBX category, but searching didn't result in any hits... Anyone ever heard of this type of LSD? There's a few others listed if you search ebay for R200 LSD... Thoughts? Comments? Opinions? I had someone ask me and I had never heard of them... http://cgi.ebay.com/ebaymotors/Balltec-240SX-2-way-LSD-R200-S13-S14-Silvia-Drift-SR-RB_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem360121102946QQitemZ360121102946QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Quote Link to comment Share on other sites More sharing options...
NZeder Posted January 6, 2009 Share Posted January 6, 2009 I have 2 of them and an OBX but alas my zed is still not on the road so I can't comment on how well they work. I can tell you they are very well build. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 6, 2009 Share Posted January 6, 2009 I'd like to understand how it works. Can anyone point me in the right direction? Quote Link to comment Share on other sites More sharing options...
NZeder Posted January 6, 2009 Share Posted January 6, 2009 Maybe these will help http://www.geocities.jp/crazy_shift/ballteck.html http://www.kisnet.ne.jp/~ken1gc10/Ball1.htm Quote Link to comment Share on other sites More sharing options...
kj280z Posted January 6, 2009 Author Share Posted January 6, 2009 Has anyone actually tried an installation? I'm with John - I'd like to learn more I have looked at the pictures you sent (thanks) and I'm still digesting it Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 6, 2009 Share Posted January 6, 2009 It looks to me like its really close to a posi with a "non-smooth" breakaway torque. At this point I think it's best for drifting, but like you Ken, I need to digest the photos more. OK, upon further "mental-modeling" I seem to understand how it works. The balls and plates, are free to move left and right inside the case. Imagine holding the case in a vice. Apply torque to ONE of the output shafts. The "zig-zag-ball-track" from the rotating output shaft will cause the ball-plate assemblies to slide laterally and "cam" the other output shaft (which is out of phase with the opposite track) into turning the opposite direction. Think "barrel-cam". Now that we see that the left and right shaft are mechanically linked via the ball-plates and cam tracks, resistance to opposite rotation (breakaway-torque) is purely a function of the spring loaded clutch pack in between the two output barrels. Ignoring ball and track friction. Understand? In theory, this should be a smooth acting breakaway, but with torque being applied from the input shaft, the friction in the ball-tracks could cause some stiction and inhibit smooth breakaway. In fact, under large input torque, depending on the phase of the balls with the cam track, it could be a rising breakaway torque with rising input torque. (I really can't fully model this in my head without seeing it first). Quote Link to comment Share on other sites More sharing options...
johnc Posted January 6, 2009 Share Posted January 6, 2009 My guess is that its a clutch pack LSD with a different clamping mechanism. Instead of the traditional ramps it uses balls and grooves. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 6, 2009 Share Posted January 6, 2009 I think that the balls and grooves do nothing more than transfer torque from the ring gear to the clutch pack AND allow opposite rotation of the left and right outputs. They are a clever, direct, replacement for spider gears. Nothing more. All the breakaway torque is achieved with a spring loaded clutch pack. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted January 6, 2009 Share Posted January 6, 2009 I don't think the L&R ball track peices rotate with respect to one another. I think the balls just force them togethor, based on the angle of the tracks, and whether its accel or deccel. What I don't understand is where the spider gears are. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 6, 2009 Share Posted January 6, 2009 I don't think the L&R ball track peices rotate with respect to one another. I think the balls just force them togethor, based on the angle of the tracks, and whether its accel or deccel. What I don't understand is where the spider gears are. Agreed and it looks like they have a shallower ramp for accel and a steeper one for decel, basically giving a 1.5 way type action. I'm also a bit confused by the lack of spider gears. The unit looks like it only has 4 drive clutches, so at 2 per side that may be a weakness. Big torque may strip the tabs off the clutches just like it does on the 300ZXT diffs... Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 6, 2009 Share Posted January 6, 2009 If that's the case, then how do the output shafts rotate opposite of eachother? Each drum has to have a splined section within it that could rotate independantly which is not shown in any photos. The spider gears are mechanically replaced by the balls and tracks. All engine torque is driven through the balls, not the tabs on the clutch discs. The tabs on the clutch discs should only see breakaway torque when a wheel gets loose. I agree that it looks like the ramps increase-decrease pressure on the clutch packs with accel/decel but viewing it that way makes you wonder how does it perform "differential" duties without spider gears...as you both realized. I think that the two grooved drums can rotate independantly as the balls track around left-right like a merry-go-round when it breaks away. Quote Link to comment Share on other sites More sharing options...
NZeder Posted January 6, 2009 Share Posted January 6, 2009 If that's the case, then how do the output shafts rotate opposite of eachother? Each drum has to have a splined section within it that could rotate independantly which is not shown in any photos.correct each drum does have the spline in them. The 2 that I have a different versions one with takes the type of axles with the C-Clips on the axles and the other is the type that holes the C-Clips with-in the spline. One has the large pre-load spring inside the other does not. I am waiting to find another 4.1 or a 4.4 diff so I can install one of these - however I still need a zed on the road too (or one that has an engine in it) might just have to put one into a mates car and go to the track, once his car is back on the track again too - it is panel shop after a meeting with the armco. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 6, 2009 Share Posted January 6, 2009 correct each drum does have the spline in them. The 2 that I have a different versions one with takes the type of axles with the C-Clips on the axles and the other is the type that holes the C-Clips with-in the spline. One has the large pre-load spring inside the other does not. I am waiting to find another 4.1 or a 4.4 diff so I can install one of these - however I still need a zed on the road too (or one that has an engine in it) might just have to put one into a mates car and go to the track, once his car is back on the track again too - it is panel shop after a meeting with the armco. That's what I thought; the side gears are inside the housings with the tracks in them. So what we're missing is the spider gears. How does that bit work? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 6, 2009 Share Posted January 6, 2009 correct each drum does have the spline in them. The 2 that I have a different versions one with takes the type of axles with the C-Clips on the axles and the other is the type that holes the C-Clips with-in the spline. One has the large pre-load spring inside the other does not. I am waiting to find another 4.1 or a 4.4 diff so I can install one of these - however I still need a zed on the road too (or one that has an engine in it) might just have to put one into a mates car and go to the track, once his car is back on the track again too - it is panel shop after a meeting with the armco. Is the spline part of the drum or is it an insert that can spin inside the drum? That is the key to understanding this. I love puzzles. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted January 6, 2009 Share Posted January 6, 2009 the reason I think they don't spin independently of each other is the cage for each set of ballz. each pair is constrained a certain distance apart. If both sides were to rotate independently, then the balls would have to more farther apart and closer together throughout its rotation to stay in the tracks. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 6, 2009 Share Posted January 6, 2009 the reason I think they don't spin independently of each other is the cage for each set of ballz. each pair is constrained a certain distance apart. If both sides were to rotate independently, then the balls would have to more farther apart and closer together throughout its rotation to stay in the tracks. That was my initial hunch also. I then thought that if the two drums rotated opposite eachother at the same rate, the tracks would be the same distance apart all the way around all the time. See what I mean? /// /// The balls and plates would just zig and zag left to right maintaining equidistance. Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted January 6, 2009 Share Posted January 6, 2009 That was my initial hunch also. I then thought that if the two drums rotated opposite eachother at the same rate, the tracks would be the same distance apart all the way around all the time. See what I mean? /// /// The balls and plates would just zig and zag left to right maintaining equidistance. I see what you mean, but I think that would only work if the zig and the zag had the same angle. Not sure though... Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted January 6, 2009 Share Posted January 6, 2009 Excellent point! Attached is a short model and video clip of what I was thinking for differential action, replacing the spider gears. Note the two cam drums rotating in opposite directions. Baltec-Counter-rotate.zip Quote Link to comment Share on other sites More sharing options...
Flexicoker Posted January 6, 2009 Share Posted January 6, 2009 I have to wait until I'm off work to watch =( Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 6, 2009 Share Posted January 6, 2009 Your video didn't work for me. You could see the parts, but no rotation. I really don't think that these drum pieces act like the spiders. If nothing else I would think that different wheel speeds would tend to want to walk the drums back and forth as they resisted the ramps, and that shaking back and forth would probably be a good way to spit out a CV axle or damage the carrier. If I'm wrong I'd like to know but I really think there have to be spiders inside the drums. Also I'm 99.9% sure the shaft part that you have sticking out the side is an assembly aid, not part of the LSD. There is a Dana LSD called a Trak-Lok (real POS by the way) and to reassemble it you have to insert a bolt through the spiders to compress the springs that preload the clutch stack in order to fit it into the housing. Once installed the bolt is removed and the clutches are preloaded. This diff looks like it has a stack of belleville springs in the middle of the drums (which makes the spider gears even more of a mystery) and the bolt that you've shown there is just used to compress the drums together so that the case can be reassembled. At least that's my guess from the pictures. Quote Link to comment Share on other sites More sharing options...
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