Greenstreak-Andy D Posted August 26, 2004 Share Posted August 26, 2004 Will be re-building the rear axle pretty soon, so am looking into the possibility of fitting a LSD. The Quaiffe ATB LSD seems to be prefered to others that could be used. Is this the one to go for? Can the amount of slip be adjusted? If so any advice? Any tips for axle re-build? Thanks in advance.... Andy Quote Link to comment Share on other sites More sharing options...
pete g Posted August 26, 2004 Share Posted August 26, 2004 this type of LSD requires no adjustments ,just the standard measurement you would do on a standard diff. Quote Link to comment Share on other sites More sharing options...
Matt Seabrook Posted August 26, 2004 Share Posted August 26, 2004 The ATB is a great bit of kit UNTIL you lift a wheel then it is no better than an open diff. On an independent rear axle it would be my choice but on a live axle like I have on my racecar I will be going for a plate type this winter. The live axle is very likely to lift the inside wheel so with a plate diff you will still have drive out of the corner with the ATB you will be back at an open diff situation. If the car is to be road use then either would be fine but a race car with a live axle then my choice would be a plate type diff. HTH Quote Link to comment Share on other sites More sharing options...
pete g Posted August 26, 2004 Share Posted August 26, 2004 matt think you got it wrong mate ATB DIFF works like a standard diff on normal conditions, until one wheel loses grip ,then it locks up to give max grip to both wheels, plate lsd has both wheels locked together all the time until one wheel reaches the preset loading point when it begins to slip regards pete Quote Link to comment Share on other sites More sharing options...
Richard M Green Posted August 26, 2004 Share Posted August 26, 2004 I have an ATB fitted into my SEW, and whilst I understand Matt's theoretical point about the behaviour of an ATB with a wheel lifted, in four seasons in the Speed Series plus track days various I have never had a problem. (Possibly because I'm not going quick enough.....) In summary: I'd recommend an ATB to anyone with an SEW for road or track use. Quote Link to comment Share on other sites More sharing options...
Matt Seabrook Posted August 26, 2004 Share Posted August 26, 2004 Sorry Pete I may not have explained it well if one wheel loose traction completely i.e. lifts a wheel the ATB will act like an open diff. If there is at least some resistance then the ATB will work. Quote Link to comment Share on other sites More sharing options...
pete g Posted August 26, 2004 Share Posted August 26, 2004 still not understand what you saying matt the more a wheel is of the ground the more the lsd should lock up.till 100% the problem with the atb lsd that i found was you can easy spin the car if you keep your foot to the floor when hitting a slipply surface,but has long as you let off quickly car straighten up again. you tend to get a lot less understeer to with the atb diff on normal driving ,i have tryed both and the ATB is a lot more user friendly.quieter and less mantenance.in fact no mantenance. regards pete Quote Link to comment Share on other sites More sharing options...
Greenstreak-Andy D Posted August 26, 2004 Author Share Posted August 26, 2004 I can see the confusion here, but looking at Quaiffe web site only found this...... The Quaife Limited Slip Differential is an Automatic gear-operated Torque Biasing differential. Sets of floating helical gear pinions (1) mesh to provide the normal speed differential action. (2) Center spring provides pre-load. In the event of a wheel slip, torque bias is generated by the axial and radial thrusts of the pinions in the pockets (3). The resultant friction force enables the driving road wheel and sun gear (4) to transmit a greater proportion of the torque. This effect is progressive, but at no stage does the differential lock solid. With a wheel lift situation, ie no torque on that wheel, the 'torque bias' would be at its least. The diff would assume both driven wheels have equal traction and thereby operate as an 'open diff'. I tend to agree with Matt on that point, but like the Quaiffe design as there is little to wear out, ie no plates to replace. Can anyone offer any tips on the axle re-build. eg oils, should ALL bearings be replaced? any special tools needed? Thanks, andy Quote Link to comment Share on other sites More sharing options...
pete g Posted August 26, 2004 Share Posted August 26, 2004 i must be missing somethink here nevermind Quote Link to comment Share on other sites More sharing options...
Blatman Posted August 26, 2004 Share Posted August 26, 2004 the more a wheel is of the ground the more the lsd should lock up.till 100% With a plate diff this is true. With an ATB this isn't true. An ATB relies on "seeing" torque at both wheels to work. With a wheel off the ground, the diff sees no torque, so it thinks it's travelling straight and level and doesn't do any torque biasing due to the lack of torque.... Can anyone offer any tips on the axle re-build. eg oils, should ALL bearings be replaced? any special tools needed? Get it done by a pro. It's about a oner at Road and Race Transmissions, and Phil will do an A1 job. Quote Link to comment Share on other sites More sharing options...
pete g Posted August 26, 2004 Share Posted August 26, 2004 lets get this clear on a standard diff if you lose grip or lift a wheel that wheel will spin and the one with grip or on the ground will stop ie lose drive.right or wrong ? on a plate lsd diff both wheels turn together ,and if grip or wheel lifts drives both wheels anyway,but when one wheel grips more than the other by the pre sett setting,it will lose grip to that wheel and transmit to other wheel.right or wrong? on ATB diff when one wheel loses grip or lifts ,it see,s that wheels turning at different speeds and begin to lock up diff to give drive to slower wheel.[on standard diff you would lose drive]right or wrong Quote Link to comment Share on other sites More sharing options...
adhawkins Posted August 26, 2004 Share Posted August 26, 2004 on ATB diff when one wheel loses grip or lifts ,it see,s that wheels turning at different speeds and begin to lock up diff to give drive to slower wheel.[on standard diff you would lose drive]right or wrong I think the key difference is between losing grip, and lifting. When the wheel starts to lose grip, it is still seeing some torque. However, when it lifts off the ground completely, there is no torque (I think this is what Blatters is trying to explain). The different types of LSD handle this in different way, and it appears he's trying to say that an ATB will provide no drive whatsoever if one of the wheels is off the ground. I think. Andy Quote Link to comment Share on other sites More sharing options...
Blatman Posted August 26, 2004 Share Posted August 26, 2004 on ATB diff when one wheel loses grip or lifts ,it see,s that wheels turning at different speeds and begin to lock up diff to give drive to slower wheel.[on standard diff you would lose drive]right or wrong Wrong.... for the 3rd time An ATB with a wheel in the air behaves like an open diff. The lack of turning resistance on the airborne wheel is what confuses the internal gears. It's a well known, well documented idiosyncrasy. With both wheels on the floor (even *only just*, ie at extreme angles) there's enough torque bias to make it work. As soon as one wheel loses contact with the tarmac, the lim slip action fails. Not sure how I can explain it any more clearly than that. And as Richard has said, in over 5 years of sprints etc, I too have never lifted an inside rear wheel off the tarmac, although I have an SEi.... Quote Link to comment Share on other sites More sharing options...
pete g Posted August 26, 2004 Share Posted August 26, 2004 still dont get it when you say open diff ,do you mean same as standard. i once broke a drive shaft clean off in a mini with a standard diff,this resulted in complete loss of drive,i was under the impression that if atb lsd was fitted it would still have drive through other drive shaft. or am i wrong again Quote Link to comment Share on other sites More sharing options...
adhawkins Posted August 26, 2004 Share Posted August 26, 2004 Yes, an open diff is a 'standard' (not limited slip) diff. And I'm afraid I think you are wrong again. It appears to be a strange characteristic of the ATB style diff. Andy Quote Link to comment Share on other sites More sharing options...
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