ijonsson Posted June 22, 2015 Report Share Posted June 22, 2015 Hi, before rushing of buying new solenoid, I'd like to know how a faulty solenoid manifests itself. OD engages sometimes at once and often not and occasionally after a couple of minutes. I've checked output from relay and it always "clicks" and have 12+ output on terminal to solenoid when flipping the stalk. OD mechanically works when solenoid "donk"/engages, so as far as I can understand it must be a problem with the solenoid, or ....? Quote Link to post Share on other sites
TriumphV8 Posted June 22, 2015 Report Share Posted June 22, 2015 (edited) The solenoid has two rows of wire, one holds the magnet and one pulls with high current and than is switched off internally. The A-Type builds up pressure inside of up to 27 bars that is guided to the clutch cylinders by the solenoid. So when the car is standing the first check is if the solenoid switches and not only the relays. There is a loud "click" from underneath when pulled and 4th gear is in. Fiddeling there with the gearstick forward backward helps to identify a worn switch on the gearbox But when the car drives the 27 bars sit behind the valve building up power to prevent the solenoid to switch. To do that safely the internal power switch of the solenoid must work properly. Can be checked with the power required first when solenoid is switched. After very short time the power drops to supplying only the holding cicuit. If tendecy is that overdrive works better when cold the accumulator may be worn. If it works sometimes and sometimes not the oil level may be the culprit. Edited June 22, 2015 by TriumphV8 Quote Link to post Share on other sites
RogerH Posted June 22, 2015 Report Share Posted June 22, 2015 Hi Inge, if the relay and the solenoid appear to operate and engage then the problem is within the GB/OD not the solenoid. When the solenoid operates does the lever with the alignment hole move correctly on the righthand side of the GB - if so then again it looks like an OD internal fault. What oil are you using Can you check the pressure in the OD Roger Quote Link to post Share on other sites
ijonsson Posted June 22, 2015 Author Report Share Posted June 22, 2015 I've tested through the gears standing still in the garage and all switches work ( I have switches on 2nd, 3:rd an 4:th) you can always hear the relay click and I also checked so the volts coming out from the relay is OK. I can't see any difference between driving (hot) or standing still in the garage. As I said earlier from time to time the solenoid engages after some time, can be 30 sec or 1 min., no difference between driving and standing still cold, sometimes the solenoid "dunks" in at once. Once engaged the solenoid holds until you flip the stalk or drop out of gear. Quote Link to post Share on other sites
ijonsson Posted June 22, 2015 Author Report Share Posted June 22, 2015 (edited) Hi Inge, if the relay and the solenoid appear to operate and engage then the problem is within the GB/OD not the solenoid. When the solenoid operates does the lever with the alignment hole move correctly on the righthand side of the GB - if so then again it looks like an OD internal fault. What oil are you using Can you check the pressure in the OD Roger I can't check the pressure, but as I said, if the solenoid engages so does the OD and holds until disengaged. The oil is the same as in engine 20W50 Classic. I checked and aligned the lever this winter so I don't think that's the problem either. I'm quite sure it's the solenoid that's gone, but I was hoping someone else had experienced a faulty solenoid and could tell me how it behaved when breaking down. I understand that the way it will show is different depending on if it's inner or outer coil or even the internal switch. Edited June 22, 2015 by ijonsson Quote Link to post Share on other sites
TR 2100 Posted June 22, 2015 Report Share Posted June 22, 2015 When solenoids "go", it's invariably terminal. AlanR Quote Link to post Share on other sites
RogerH Posted June 22, 2015 Report Share Posted June 22, 2015 Hi Inge, as you have stated there are two coils in the OD solenoid. If the pull in coil fails then it will NOT pull in and nothing happens.. If the hold in coil fails it will NOT hold and will 'chatter' You state that you are using 20/50 engine oil in the OD. To my mind this is the worst that can be used. It contains detergent and will froth (bubble). These bubbles will stop or reduce the working of the OD pump. Change to a gearbox oil - I use Penrite 40 grade gearbox oil. Roger Quote Link to post Share on other sites
Guest ntc Posted June 22, 2015 Report Share Posted June 22, 2015 Hi Inge, as you have stated there are two coils in the OD solenoid. If the pull in coil fails then it will NOT pull in and nothing happens.. If the hold in coil fails it will NOT hold and will 'chatter' You state that you are using 20/50 engine oil in the OD. To my mind this is the worst that can be used. It contains detergent and will froth (bubble). These bubbles will stop or reduce the working of the OD pump. Change to a gearbox oil - I use Penrite 40 grade gearbox oil. Roger Roger Load of Boll!!!! speak to somebody that knows Quote Link to post Share on other sites
Nick Jones Posted June 22, 2015 Report Share Posted June 22, 2015 As the solenoid has two coils it also has a microswitch on the end of it which switches from pull-in coil to holding coil. The switch contacts can get dirty/burnt/pitted and cause problems similar to yours. They are not really intended to be serviceable but can be with a bit of care. Dirty /damaged connections between the relay and the solenoid and between the solenoid and earth can cause similar issues. An ammeter is a useful tool to show what is really going on electrically but you need a fairly hefty one as the pull-in coil takes >10A Nick Quote Link to post Share on other sites
ijonsson Posted June 22, 2015 Author Report Share Posted June 22, 2015 As the solenoid has two coils it also has a microswitch on the end of it which switches from pull-in coil to holding coil. The switch contacts can get dirty/burnt/pitted and cause problems similar to yours. They are not really intended to be serviceable but can be with a bit of care. Dirty /damaged connections between the relay and the solenoid and between the solenoid and earth can cause similar issues. An ammeter is a useful tool to show what is really going on electrically but you need a fairly hefty one as the pull-in coil takes >10A Nick At least I'll check volts at solenoid terminal to check that I haven't a voltage drop somewhere. I took out the Amp-meter and put in a Volt-meter in the TR, so maybe I could use that old amp-meter to at least get an indication of what's going on Quote Link to post Share on other sites
RogerH Posted June 22, 2015 Report Share Posted June 22, 2015 Hi Neil, I accept that there are some very clever people around but I refuse point blank that engine oil should be used in a gear box with or without an OD. There is a great deal of science behind lubrication and the boys in the lab design oil for the right job. Gearboxes require gearbox oil Engines require engine oil. Roger Quote Link to post Share on other sites
Dave McDonald Posted June 22, 2015 Report Share Posted June 22, 2015 Inge You haven't said, unless I've missed something, whether or not you've had the gearbox cover off to physically inspect the solenoid. I had a similar problem with the A type overdrive in my TR5. The overdrive eventually refused to work at all even though I could hear the solenoid clicking. On removing the cover I found that the solenoid mounting bracket (Moss part 502566) had broken. The right angled flange that the solenoid bolts to had broken clean off the main side cover part of the unit so that the when the solenoid operated it had nothing to push against. When replacing it I changed the accumulator spring while I was at it. Oh, and I filled the unit with fresh Penrite 40 gearbox oil, also available at Moss. That and the spring both on the recommendation of Pete Cox. I think he falls into the bracket of someone that Neil refers to as "....someone who knows." Dave McD Quote Link to post Share on other sites
mjdearing Posted June 23, 2015 Report Share Posted June 23, 2015 dont count on the setting being right with the dowel through lever hole etc,disconnect solonoid lever and run car and operate lever manually watch yer pinkys on that prop though. Quote Link to post Share on other sites
ijonsson Posted June 23, 2015 Author Report Share Posted June 23, 2015 (edited) Okej, nothing wrong with OD. Measured the volts at output from relay to solenoid, battery was at 12,3 V and after relay it was 11,9 V (engine not running). So, I've taken out the H-frame (and some) so I could access the hatch I'd made earlier in the GB-cover for gaining access to the solenoid . Made a direct feed from battery and nothing happened, even tried with a spare battery, but nothing. Took a direct feed from a battery charger that gives 13.3 V and now the solenoid acts as it should. I broke the relay open and coldn't see anything funny inside, cleaned the contact points though. Checked the solenoid plunger, but its moving freely so that's not the problem. Seem just that the solenoid needs a lot of "juice". That might explain why it works sometimes when driving and alternator is charging more than 12.5 V. Shouldn't a solenoid work at least at 12.5 V??? Edited June 23, 2015 by ijonsson Quote Link to post Share on other sites
RogerH Posted June 23, 2015 Report Share Posted June 23, 2015 Hi Inge, with a direct connection to the solenoid I would have thought it should work with a lot less volts than 12.5. Roger Quote Link to post Share on other sites
AlanT Posted June 23, 2015 Report Share Posted June 23, 2015 Remove solenoid. Clean the hole and make sure the plunger moves freely. I'd suspect this has gone sticky inside, maybe some rust in there. Or the contacts for the high current coil need to be cleaned. Check by making connection to a battery before refitting. Its not too hard to fix these with a bit of TLC. Quote Link to post Share on other sites
Guest ntc Posted June 23, 2015 Report Share Posted June 23, 2015 Hi Neil, I accept that there are some very clever people around but I refuse point blank that engine oil should be used in a gear box with or without an OD. There is a great deal of science behind lubrication and the boys in the lab design oil for the right job. Gearboxes require gearbox oil Engines require engine oil. Roger Roger Tell MG that Quote Link to post Share on other sites
ijonsson Posted June 23, 2015 Author Report Share Posted June 23, 2015 Remove solenoid. Clean the hole and make sure the plunger moves freely. I'd suspect this has gone sticky inside, maybe some rust in there. Or the contacts for the high current coil need to be cleaned. Check by making connection to a battery before refitting. Its not too hard to fix these with a bit of TLC. Just been in the garage doing that, plunger moves freely, took the top cover of and contacts look like new on solenoid. It did work once and then gave up even with 13.3 V so I'm ordering a new one. It's pouring down outside and 13 degC so not weather for TR-ing with top down anyhow. Thanks all for advice, will tell later of outcome. Quote Link to post Share on other sites
ijonsson Posted June 30, 2015 Author Report Share Posted June 30, 2015 Got the new solenoid yesterday and fitted it, adjusted lever position and refitted everything. Didn't take out GB cover, but it has some new holes and bungs now, it now has as many holes as a Swiss cheese. Took a 60 miles drive today and OD works just as it should, . http://www.ijonsson.se/triumph/diary.php?day=el Quote Link to post Share on other sites
RogerH Posted June 30, 2015 Report Share Posted June 30, 2015 Hi Neil, MG's need the oil on the outside - to slow down the rust Roger Quote Link to post Share on other sites
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