” I have a lookalike with same number ID on the core. No idea where it comes from, I found it in a rear axle of a Sprite MK 1 or 2 which I bought for the casing. Never found time to take it apart but Colin Dodds from down under told me it is an “all or nothing” LSD as described by Bill and Chris. Here are some pictures! Regards Kees (van Beijmerwerdt)
More detail from Chris dimmock (Sydney, Australia):
“The “No Spin” diff was patented, and manufactured, by the Detroit Automotive Products Corporation. Hence “Detroit Locker”. Mine has been with my Healey 3000 since 1969. When you stand on the power, and don’t lift off, it propels the car in a straight line wherever you aimed it! Link to allcylinders.com website“
Spridget Detroit Locker
And another – from Chris dimmock
“I have a Detroit Locker for my Healey 3000. Detroit Lockers are still used in NASCAR last time I checked, and they are awesome. Reliable and bulletproof and no more maintenance than a standard diff. Perfect! They lock, and then if you lift, they unlock. Straight away. No slip. Ratchet and pawl design. Once you understand that’s what they do, they are awesome on the track!! They have only 2 downsides. Firstly, a wet road makes them undriveable. On the road, you pretty much have to push the clutch in on low speed corners, because it might lock/ unlock 10 times… Because when they lock/ unlock, the rear of the car steps out 3 feet or so. Which is fine in the dry. But go for the power in a Healey 3000 in the wet, just a fraction too early…. And you’re not sliding – its “come home spinner”!!!”
“Happy to chat about my experiences with a Detroit Locker in my Healey 3000 https//:www.myaustinhealey.com I used my Detroit Locker on the road, and on the track, for probably 6 years. The day I spun at Oran Park Circuit, in the wet, and thought ‘thank you God, I didn’t go off the track on the inside, slide down the steep grassy hill, and end up in a lake’ – was the day I took it out. Because it stalled. And I had 6 cars bearing down on me. I was backwards, parked/stalled on the corner exit like, with 3 flooded webers… looking at oncoming cars! Because of their talent, everyone missed me. But it was caused just because I was just a nanosecond or 2 early on the power…”
A reply from Bill Mcdonnough of Hardy Engineering
“As you can see in the pics we have the big brother version out of a Healey 3000. This one came in a diff core unit years ago and we have never been brave enough to put it in a car. It is what the Americans refer to as a ‘Detroit Locker’ Generally advertised as a ‘ no spin’ device. Helps you off a junction etc. We have no history on the unit we have I’m afraid. It looks very 60’s in its manufacture but these would have had to have been specials with the coarse English spline design (Ford were on a fine spline from the late 50s) There is mention of the Morley brothers having an ‘experimental’ LSD fail on them in a 3000 rally car in period so I take this to not be a Salisbury ( plate/ clutch type) idea from the Jaguars as these are tried and tested as a standard fit in E types etc. Both these units are not converted but ‘new builds’ and Jack knight have always marked their products with JKD which we do not have here. Ours is marked ‘qvp’ ? I cannot see how these would have had that big a market at the time?? More likely in the 70s/80s then? Maybe we both have items of period racing history….or maybe we do not? but it is always nice to think someone famous once gave these LSDs torment in a works car !!
Very interested to know how the A series one performs?
Best Regards. Bill McDonough.
Hardy EngineeringHardy Engineering Transmissions Ltd
268 Kingston Road, Leatherhead’ Surrey KT22 7QA
01372 378927
Can you help identify Erick Moser’s LSD?
Martin, Thank you for all the work you do keeping Sebring Sprite running so efficiently. I write to see whether the site visitors can help me with a puzzling vintage Sprite differential.
I recently bought it from a guy in the US who raced with it some years back in a Frogeye. The alloy pumpkin has the cast numbers from the BMC Special tuning catalog along with “4.55” (it is indeed a 4.55 ring and pinion) and a date of “14.5.59”. The Special Tuning catalog mentions a “clutch type” LSD, but this is a locking type with the numbers 64540 on the carrier and ATA7091 on the ring gear. I’ve provided a bunch of photos. It works fine, I’ll be running it in my tarmac autocross Frogeye.
Is it perhaps a different BMC competition product? Could it have been offered by Jack Knight Developments or something? Is it an early Hardy Spicer diff in a special tuning case? I can’t find any solid leads to answer these questions. Perhaps some of the competition Sprite experts can shed some light on it.
Thanks, Erick
Feedback please.
