willis Posted July 9, 2019 Report Share Posted July 9, 2019 Hi folks, Can anyone advise me as to why my horns blast while I'm driving my car? It only seems to happen when the steering wheel is turned to the right and I need to cure it because I fear my wife might die because she's laughing so much. Talk about embarrassment. Also, my speedo (not swimming trunks) isn't working. It registers when I turn the end of the cable and also when I connect it to the angle drive but not when connected to the gearbox, so I'm assuming it's something to do with that end. Any help will be greatly appreciated. Cheers, Rob. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted July 9, 2019 Report Share Posted July 9, 2019 It's a short circuit; the horns feed is permanently live and earths through the horn push, so when you turn the wheel something shorts out and sounds the horn. Check the state of the wiring up the column, and around the wheel and the pencil-connector that links the horn push to the ring under the wheel. Re your speedo - is the cable sound at both ends; wear or fraying will shorten it just that little bit which is enough for it to make insufficient contact at one end or the other; in this case the gearbox. Try pulling the inner out at the gearbox end, just slightly, so that it still operates the speedo and see how much you have left to engage the gearbox drive - this might just be enough to engage both ends and get it working again. Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 9, 2019 Report Share Posted July 9, 2019 Yes get some grips on the end fitting and rotate the oiter case its a spiral wound sheath, so some simple turns wil lengthen or shorten the outer to make more or less protrusion of the inner to change the engagement. Pete Link to comment Share on other sites More sharing options...
willis Posted July 9, 2019 Author Report Share Posted July 9, 2019 Cheers chaps, I'll try both tips at the weekend. Rob Link to comment Share on other sites More sharing options...
willis Posted July 15, 2019 Author Report Share Posted July 15, 2019 Hi folks, The horns seem to be ok at the moment after a bit of adjustment of the column. However, I've still got no working speedo despite trying all sorts of things. I'm wondering if there is a bit of a old cable end stuck in the part that the gearbox that the angle drive fixes onto. The speedo cable is new but the old one worked fine when the car was taken off the road, and as I said before, I can make it work when the angle drive is fitted to the speedo cable and turn that by hand. I'm thinking about taking the part that the drive fixes onto the gearbox off the car and trying to see if there's anything inside that should not be there. What are your thoughts on this and what problems am I likely to encounter? Cheers, Rob Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 15, 2019 Report Share Posted July 15, 2019 the overdrive speedo drive assy i s held in with one spigot set screw , its sealed to the case with an O ring with can need some effort to pull the drive out getting the pinion out of the hsg. is another story ,its held in with a non removable pin angle drives can fail especially if no spacer washer was fitted . Pete Link to comment Share on other sites More sharing options...
willis Posted July 15, 2019 Author Report Share Posted July 15, 2019 Cheers Pete, there seems to be a copper washer in the angle drive fixes to the gearbox but it doesn't appear to come out. Is this the one you mean or should there be a separate one? Rob Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 16, 2019 Report Share Posted July 16, 2019 Its a loose seperate washer , 7/16dia its ona BL tech note , even rimmers say no warranty if missing but dont list the washer Any washer will space the drive so the input is not preloaded. Not uncommon to shear the square drive , it does come apart , if needed and repair is variable diy ideas Theres a number of posts about these on here, More importantly does yours work ???? Youmcan spin the drive and cables with a drill Pete Link to comment Share on other sites More sharing options...
mark powell Posted July 16, 2019 Report Share Posted July 16, 2019 16 hours ago, Pete Lewis said: the overdrive speedo drive assy i s held in with one spigot set screw , its sealed to the case with an O ring with can need some effort to pull the drive out getting the pinion out of the hsg. is another story ,its held in with a non removable pin angle drives can fail especially if no spacer washer was fitted . Pete Some say 'don't try to dismantle the speedo pinion housing' but following a post on a 'marque who shall not be named' site, I have successfully done this. Now a waiting new seals from Paddocks. https://www.mgexp.com/article/mgb-dtype-overdrive-speedo-pinion.html This will not cure a non-working speedo however... Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 16, 2019 Report Share Posted July 16, 2019 thanks Mark, hes not showing how to locate the drill to remove the pin , they skip the need to know bit,, this would need some care to alignments and best in a pillar drill and firm vice , my guess would be theres little point in relacing the pin i dont think anything will unscrew, maybe a dab of loctite like most anything is possible , like they say the difficult takes time the impossible a little longer ha ! Pete Link to comment Share on other sites More sharing options...
willis Posted July 16, 2019 Author Report Share Posted July 16, 2019 Hi chaps, I can make the speedo work by spinning the end of the cable with my fingers and also when the angle drive is fitted to the end of the speedo cable. It's only when they're connected to the gearbox that I get no reading on the speedo. I'll try to fit another washer between the drive and the 'box at the weekend and I'll let you know how I get on. Cheers, Rob Link to comment Share on other sites More sharing options...
johny Posted July 16, 2019 Report Share Posted July 16, 2019 I take it the internal drive in the gearbox has been confirmed as driving ok? Unlikely to fail but I suppose its possible so can it be proved by putting something suitable in the gearbox drive end to check it rotates when the back wheels turn? Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 16, 2019 Report Share Posted July 16, 2019 a washer wont help it drive , I would conncet the drive and spin the wheels does it connect ok between the OD output and drive the angle output , 1 washer can be added when youve sussed what wrong the washer just preserves the angle drive gears . sound like the speedo pinion is not driving the angle drive Pete Link to comment Share on other sites More sharing options...
willis Posted July 16, 2019 Author Report Share Posted July 16, 2019 I'll check to see if the gearbox internal drive is working ok at the weekend. Maybe connecting the speedo cable direct to the 'box would help me detect this? Ah well, onwards and upwards. Cheers, Rob Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 16, 2019 Report Share Posted July 16, 2019 there can be a wide variety of the drive ends on cables and such like there squares flats, ovals, and size matters thrown in . if the speedo works when you drive the removed angle head then its a problem with the angle stub cable not locating in the speedo pinion pete Link to comment Share on other sites More sharing options...
willis Posted July 20, 2019 Author Report Share Posted July 20, 2019 Hi chaps, took speedo cable, angle drive and the part of the gearbox that the angle drive fastens to, off the car which revealed the shaft that the angle drive cable fits into. With the engine running and in gear, the shaft isn't turning so there must be something wrong inside the 'box. Are there any replacement parts that I can buy to fix this and if so, how do I do it? Cheers, Rob Link to comment Share on other sites More sharing options...
johny Posted July 20, 2019 Report Share Posted July 20, 2019 oh dear that sounds like the worst scenario, are you 100% sure the drive in the gearbox isnt turning (can you put something in it)? If it isnt then the problem is with the plastic drive gears inside with one mounted on the OD output shaft and the other on the end of the little shaft the angle drive connects to. First thing is to remove this little shaft assembly to inspect its gear but when you do this oil may come out depending on the level in the gearbox. If your very lucky it may just be this gear thats damaged and not the other (although as they run together Id expect both to have suffered) so you can get away with just replacing it with a new one of the correct ratio. In the opposite case the OD will need to be removed and opened up..... Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 21, 2019 Report Share Posted July 21, 2019 Wont be the first to find the last od repair left the worm out or the od pump keyway Hopefully its the pinion , Pete Link to comment Share on other sites More sharing options...
willis Posted July 21, 2019 Author Report Share Posted July 21, 2019 Cheers chaps, I bought the gearbox from Canley Classics albeit a few years ago now, so I can't confirm if it was rebuilt properly or not, but coming from them I would expect so. Is it possible to remove the pinion with the 'box still in the car or will I have to take it out? Also, how difficult is it to remove the pinion. Rob Link to comment Share on other sites More sharing options...
johny Posted July 21, 2019 Report Share Posted July 21, 2019 I think the pinion assembly will come out with the gearbox in place but as access might be tight you might have to undo the gearbox mountings and jack it up slightly. Its easy to undo the pinion fixing bolt but the assembly might need a bit of a pull to remove from the OD casing (its sealed with an o-ring that can stick). Some oil will come out as you do this (less if you have jacked up the rear of the box) so you can either drain the gearbox from its normal drain plug beforehand or just catch what comes out from the pinion hole. Should be an easy job and then you can inspect the pinion gear and also feel with a finger the condition of the worm gear inside the OD.... Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 21, 2019 Report Share Posted July 21, 2019 its held in with a single setscrew has a spigot end just unscrew then may need effort to drag the drive out its only held by an O ring which can stick refit means you must align the hole in the drive hsg. with the bolt hole. pete Link to comment Share on other sites More sharing options...
willis Posted July 22, 2019 Author Report Share Posted July 22, 2019 Will I need a new O ring or will I be able to reuse the original one? Another weekend job unfortunately. Rob Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 22, 2019 Report Share Posted July 22, 2019 the 0 ring should be ok for re use, a light smear of sealer might be an idea, only a smear you may need to remove again some time Pete Link to comment Share on other sites More sharing options...
johny Posted July 22, 2019 Report Share Posted July 22, 2019 If the pinion assembly takes quite a bit to get out the o-ring could have stuck and then be damaged during the process. Inspect it after removal and make sure the inside of the OD casing hole is nice and clean before reassembly - the last thing you want is to find it leaking after putting the cover, carpets and facia back on..... Link to comment Share on other sites More sharing options...
willis Posted July 28, 2019 Author Report Share Posted July 28, 2019 Sorry chaps, nothing to report as rain stopped play Rob Link to comment Share on other sites More sharing options...
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