dazzer Posted November 23, 2017 Share Posted November 23, 2017 Just a heads up for the Logic overdrive kits which I've just fitted to the 2000 rally car... after a bit of faffing with some not fit for purpose parts.Once fitted its great. I have overdrive on second, third and fourth. As you select overdrive which is now one click on the momentary stick it engages as it did previously but when you change up or down it automatically disengages until you dip the switch again. So perfect if you accidentally leave the overdrive engaged and also for quick up changes. Engage second overdrive go for third you get third without flicking out, you can then dip into third overdrive and change up to actual fourth before engaging fourth overdrive.The unit itself which I got from Revington is easy to set up and locate. You have to use a Relay with the unit so if you're already set up for an A type box just a few wires to move about. I'm J type but had left the original relay in place so straightforward.The rubbish parts are the momentary switches with a long stalk if you are retaining the column switch like myself. A number are available from various sources. I've tried them all they are all absolute **@&. Flimsy and disintegrate, or just don't work. (I tried five!) I made my own from a GT6 column switch in the end and a short 25A lucas momentary switch. Works perfectly with a bit of dismantling and grinding and a bit of ingenuity. Also my 50 year 6RA relay was starting to stick and beyond refurb so I made the mistake of trying a modern equivalent Lucas 6RA... big mistake. First didn't work, second worked for an hour. I therefore used a modern 30amp 12v relay I had lying around and that works beautifully.So great system, once you sort the gremlin ancillary parts.Dazzer Quote Link to comment Share on other sites More sharing options...
Hogie Posted November 23, 2017 Share Posted November 23, 2017 Hi Dazzer, the proprietary momentary switch is quite expensive.I made a press button switch - not sure what the Revington one switches but mine allows a pulse of +12v into the circuit.The press button is on the end of a stalk located in the switch position.When driving one just needs to flick a finger rather than move a whole hand.Roger Quote Link to comment Share on other sites More sharing options...
dazzer Posted November 23, 2017 Author Share Posted November 23, 2017 Hi RogerSounds good. Yes it was the expensive proprietary momentary switches that all failed.At least we've both found a successful solution.Great system. Cheers Dazzer Quote Link to comment Share on other sites More sharing options...
Gt6s Posted November 24, 2017 Share Posted November 24, 2017 I made one for my old Sixfire. done with two relays.Laurence Quote Link to comment Share on other sites More sharing options...
Hogie Posted November 24, 2017 Share Posted November 24, 2017 Hi Laurence, 2 relays appears to be the popular method. That's what Revington use.I use two relays and a few other components just to make it more complicated.Roger Quote Link to comment Share on other sites More sharing options...
dazzer Posted November 24, 2017 Author Share Posted November 24, 2017 Hi Laurence What did you use for a momentary switch? Was it another home made model. The ones I tried came from reputable sources and a couple of switch and kit car specialists. All very fragile. My home made one is bullet proof but requires a couple of donor switches.CheersDarren Quote Link to comment Share on other sites More sharing options...
Gt6s Posted November 24, 2017 Share Posted November 24, 2017 Indeed Roger I had two warning lamps one (ready to drop out) the other (stay in on change) I did intend to wire in a clutch pedal switch to it as well but I never got round to that. Darren I used the two relays wired to self latch the OD switches provided the switching as they disconnect on change through neutral (Saloon box)Laurence Quote Link to comment Share on other sites More sharing options...
Gt6s Posted November 24, 2017 Share Posted November 24, 2017 Actually thinking about it I have the feeling I only used one relay on it wired to self latch. Long time ago I did it.Laurence Quote Link to comment Share on other sites More sharing options...
iggy Posted November 24, 2017 Share Posted November 24, 2017 Hi dazzer im very interested in this ive already got a logic overdrive box fitted to the A type gearbox in my mk2 2500 it works as it should but only in third or fourth gear bought it from ebay, does the revington tr kit work in second gear as wired to the instructions you get with it? is this the corrrect part no RTR1001k thanks Quote Link to comment Share on other sites More sharing options...
dazzer Posted November 25, 2017 Author Share Posted November 25, 2017 Hi IggyThe 2nd gear operation is another inhibitor switch fitted on top of the gearbox which when fitted and wired in line with the 3rd/4th inhibitor will work with the logic/overdrive with no extra wiring required. The inhibitor might already be there but not wired up? Cheers Darren Quote Link to comment Share on other sites More sharing options...
thescrapman Posted November 25, 2017 Share Posted November 25, 2017 IggyThe J-type saloon boxes have the additional inhibitor hole already in place, usually with a brass nut in the hole.Don't remember seeing it on the earlier saloon boxes.May need to get the appropriate selector shaft with the indent if it isn't present and then tap the hole and fit a switch Quote Link to comment Share on other sites More sharing options...
iggy Posted November 25, 2017 Share Posted November 25, 2017 ok i some how thought the revington tr kit did away with the need for the extra inhibitor switch, thanks for letting me no Quote Link to comment Share on other sites More sharing options...
iggy Posted November 25, 2017 Share Posted November 25, 2017 I remember now my earlier mk2 had overdrive in all gears including reverse,but had no inhibitor switch fitted for second gear obviously no good in reverse, but isnt there a way to wire in overdrive for second gear with out the extra inhibitor switch? Quote Link to comment Share on other sites More sharing options...
Hogie Posted November 25, 2017 Share Posted November 25, 2017 Hi Iggy, if you want OD in ALL gears then simply wire without the inhibit switches. However you stand every chance of destroying your OD box in quick order. The inhibit switches are there for a purpose.Second gear OD may actually be a higher gear than straight 3rd - so if you go 2 OD to 3rd the engine will 'race' sort of.Maybe the saloon gears are different to the early TR ratio'sThe Revington logic box will operate all gears that have the inhibit switch fitted.I found that all standard Momentary ON toggle type switches had quite a soft action (weak spring). With an extended lever it became almost floppy.That is why I went over to the press button style.This is a modified toggle switch that only uses the threaded end with the toggle pivot - the contact area is removed.However with a press button you do need a warning light to tell you where you are - In or out of OD.Roger Quote Link to comment Share on other sites More sharing options...
iggy Posted November 25, 2017 Share Posted November 25, 2017 hogie the A type overdrive on my earlier triumph was wired by the previous owner, in this case overdrive in second wasnt higher than straight third, i was thinking is there a way to get overdrive in the forward gears but not in reverse without the extra inhibitor switch? Quote Link to comment Share on other sites More sharing options...
Hogie Posted November 25, 2017 Share Posted November 25, 2017 Hi Iggy, the inhibit switches are not named very well, they actually allow that gear to be used.1st and Reverse should never go through the OD and DO NOT have inhibit switches - the torque could be too aggressive for it.Like wise on the 6 cylinder engines 2nd gear is not used for the same reason.What would be your aims if you could run 2nd OD - very limited use.So if you have inhibit switches for 3rd and 4th then these need to be wired in parallel and then fed to earth/switch etc.If you really want second OD then you will need an inhibit switch fitted to the GB top cover in the correct place and this goes in parallel with the other two.If you have a similar switch for reverse then this could well be for Reverse lighting.If you need to install a limit switch then the thread size to use is M16 x 2mm - however the actual thread is 5/8" x 13TPI but this does not exist.Good luckRoger Quote Link to comment Share on other sites More sharing options...
iggy Posted November 25, 2017 Share Posted November 25, 2017 I could be wrong Hogie but didnt some of the early Tr5s have overdrive for second gear, but yes wouldnt be using overdrive in 2nd to much anyway, also arnt the A type overdrive gearboxes stronger than the j type. i no what you mean though i think the mgb gt v8 only had overdrive in 4th gear cause off the extra tourque from the v8 engine Quote Link to comment Share on other sites More sharing options...
dazzer Posted November 25, 2017 Author Share Posted November 25, 2017 The overdrive second can slip on a standard A or J type but with uprated overdrive with a bigger pump it selects immediately with no slip and is very useful for ultra quick changes. I'll record the overdrive in action when I get a chance. Dazzer Quote Link to comment Share on other sites More sharing options...
Hogie Posted November 26, 2017 Share Posted November 26, 2017 Hi Iggy, the TR5 may well have had OD on 2nd - using up 4A stock probably.I always thought the 'J' type was a stronger OD but could be wrong and that is why it was fitted to the 6 pot cars.Roger Quote Link to comment Share on other sites More sharing options...
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