FROM: rtlowe@bogusbc.sympatico.ca (Raymond T. Lowe) SUBJECT: Re: More on Diff Locks DATE: Sat, 09 Jan 1999 21:39:16 GMT NEWSGROUPS: rec.autos.4x4 In article <7774bj$svg$1@demon.uunet.ca>, shaw@logisys.com says... > - snipped - >There are other systems such as: The Eaton Gov-lock, where the differential >is open until one wheel spins faster than the other by a certain speed and >then the unit locks up (this unit is prone to failure with off-roading >abuse); Steve, Well done a pretty detailed breakdown. I would like to point out that the factory GM Eaton build "lockers" are not open diffs. They are essentially a LSD (clutch discs) with a governor. To quote the shop manual; "Under light loads, the clutch plates alone tend to lock axle shafts to the differential case, and therefore, locking each other. This is due primarily to the gear separating load developed on the right clutch pack. This induced clutch torque capacity resists motion between the side gear and the rear axle differential case. The differential allows the wheels to turn at different speeds while the axle shafts continue to transmit the driving force. Also, heavier throttle applications will cause an axle speed differential, but this starts the full-lock feature of the unit. Full locking is accomplished through the use of a heavyweight govern- or mechanism, cam system, and multi-disc clutch packs. The flyweights on the governor mechanism move outward to engage a latching bracket whenever the wheel-to-wheel speed varies by approximately 100 rpm or more. This action retards a cam which, in turn, compresses the multi-disc clutch packs locking both side gears to the case. The 100 rpm wheel-to-wheel speed allows for cornering without differential lockup. At vehicle speeds above approximately 32km/h (20mph), the latching bracket overcomes a spring preload and swings away from the flyweights. At this vehicle speed or greater, the differential is designed to not lock, since added traction is generally not needed." Thought you might be interested. Offroad abuse may damage the unit but three years of laying rubber, hunting, offroading, hauling, etc with a 5.7 Vortec and it still works fine. Mind you its a 9.5" unit. RT -- To send email - remove "bogus" 5.4? Don't even try... FROM: AZGuy SUBJECT: Re: What is the difference between Lockers and LSD? DATE: Sun, 10 Dec 2000 22:26:04 GMT ORGANIZATION: EarthLink Inc. -- http://www.EarthLink.net NEWSGROUPS: rec.autos.4x4 On Sun, 10 Dec 00 17:51:20 GMT, w.j.markerink@a1.nl (Willem-Jan Markerink) wrote: >In article , > AZGuy wrote: >>On Sun, 10 Dec 2000 00:57:12 GMT, Jerry Bransford >>wrote: >> >>>All (ALL) automatic lockers (EZ Locker, Detroit Locker, Gearless Locker, >>>etc.) are normally fully and totally locked in their normal resting >>>state. They are completely locked while you drive around. They only >>>unlock when turning corners or driving around a curve. On slick >>>surfaces, they often don't even unlock when turning corners which is why >>>lockers can cause severe understeer in winter driving conditions. >>> >>>The Chevy unit you refer to is not (definitely not) a locker, it is a >>>LSD >> >>I don't know which one you are referring to but the one I am referring >>to IS a locker, not LSD. > >Assuming you talk about the Gov-Lock unit (there are no factory installed >auto-lockers available a la Detroit/Lockright), then it fits both >descriptions (it limits slip only above a certain rpm difference (governer >mechanism), and then locks solidly), but it DEFINATELY doesn't act as an >auto-locker when not in use....that is: it does not lock by default, and >open up in corners. >It is a normal open diff until it engages, unlike an auto-locker. You are describing the one I'm talking about. The definitions being tossed around may be what's in common usage but to me make no sense. To call a diff that is always locked except when it decides to UNlock would to me not be called an auto-locker, but an auto-UNlocker. The chevy units are what to me would logically be called auto-lockers because they automatically determine when to lock. Compare them to something like an "air-locker". Those are manual lockers. FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: What is the difference between Lockers and LSD? DATE: Mon, 11 Dec 00 00:39:50 GMT NEWSGROUPS: rec.autos.4x4 In article , AZGuy wrote: >On Sun, 10 Dec 00 17:51:20 GMT, w.j.markerink@a1.nl (Willem-Jan >Markerink) wrote: > >>In article , >> AZGuy wrote: >>>On Sun, 10 Dec 2000 00:57:12 GMT, Jerry Bransford >>>wrote: >>> >>>>All (ALL) automatic lockers (EZ Locker, Detroit Locker, Gearless Locker, >>>>etc.) are normally fully and totally locked in their normal resting >>>>state. They are completely locked while you drive around. They only >>>>unlock when turning corners or driving around a curve. On slick >>>>surfaces, they often don't even unlock when turning corners which is why >>>>lockers can cause severe understeer in winter driving conditions. >>>> >>>>The Chevy unit you refer to is not (definitely not) a locker, it is a >>>>LSD >>> >>>I don't know which one you are referring to but the one I am referring >>>to IS a locker, not LSD. >> >>Assuming you talk about the Gov-Lock unit (there are no factory installed >>auto-lockers available a la Detroit/Lockright), then it fits both >>descriptions (it limits slip only above a certain rpm difference (governer >>mechanism), and then locks solidly), but it DEFINATELY doesn't act as an >>auto-locker when not in use....that is: it does not lock by default, and >>open up in corners. >>It is a normal open diff until it engages, unlike an auto-locker. > > >You are describing the one I'm talking about. The definitions being >tossed around may be what's in common usage but to me make no sense. >To call a diff that is always locked except when it decides to UNlock >would to me not be called an auto-locker, but an auto-UNlocker. The >chevy units are what to me would logically be called auto-lockers >because they automatically determine when to lock. Compare them to >something like an "air-locker". Those are manual lockers. In hindsight, it also depends a bit on how you define 'limited slip'....the Gov-Lock first slips, then locks solid....semantically there is no inbetween stage of 'limited slip' (the engagement is quite agressive too, it can grenade your diff if you are not careful with the throttle), but on the other hand it *does* *limit* slip (to zero....8-)). To me this is more a grey area than auto-locker vs auto-unlocker.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!]