From healeys-owner Fri Jun 30 18:07:09 1995 Received: (from majordom@localhost) by triumph.cs.utah.edu (8.6.10/8.6.6) id SAA04315 for healeys-outgoing; Fri, 30 Jun 1995 18:07:03 -0400 Message-Id: <9506302208.AA04144@milliways-le0> Date: Fri, 30 Jun 95 15:08:25 PDT From: Andrew Smith To: british-cars@autox.team.net Subject: SOL Examination Paper 1: Lucas Overdrive Solenoids Cc: healeys@autox.team.net Sender: owner-healeys Precedence: bulk Reply-To: Andrew Smith X-Mozilla-Status: 0001 Content-Length: 1995 OK, guys'n gals, time to test your claim to be the genuine Scions of Lucas: Lucas overdrive operating solenoid - it's that bulge on the side of the overdrive unit that gets hotter and hotter and then tries to burst into flames if it can't achieve its goal of shifting the overdrive oil ball valve. 1) Is it normal behaviour for a solenoid to get too hot when it cannot pull its core completely into the coil winding? 2) Is it possible for it to draw so much current as to melt the supply wires before melting its own internal windings? 3) Is it possible that it has partially destroyed its own internal winding's insulation such that it shorts maybe 1/2 the winding and hence draws twice the current next time it's operated (I=V/R)? It still gives a hearty kick when energised but obviously not enough to operate the valve and stop it burning up. Anyone know what "R" should be on a healthy solenoid? 4) Shouldn't the fuse blow before igniting the whole car, not afterwards? (the wiring seems to be original and pretty heavy gauge). 5) How many 1000 turns of what gauge wire should I rewind the solenoid coil with? (new one is $150 from Moss :-( I checked the linkage to the valve and all appears to work smoothly so I don't know how it could have burnt out - maybe temporary mechanical obstruction of the exposed "overdrive calibration lever" on the far end of the OD camshaft? This is the later design of OD linkage which protects the solenoid mechanism but still leaves the exposed test lever on the opposite side which is very vulnerable to obstruction from the tranny cover for example (my tranny cover is a flimsy sort of moulded cardboard thing with not much solid in the way of floor panel remaining to screw it down to!). Andrew Smith Palo Alto, CA '60 Healey 3000 Mk.I (with Mk.II gearbox & overdrive units) Off to celebrate Britain's independance from the US .... great idea!