RogerH Posted August 4, 2014 Report Share Posted August 4, 2014 Hi Mark, I was having an 'invention moment' a while ago and needed to know what was happening. The red leds mimic the stop lights - if the stop light filament fails for whatever reason the led will not illuminate when the pedal is pressed. The green leds indicate what the overdrive is doing - I was playing with some OD logic devices and needed to know what the circuit was doing. The panel is now redundant and thje ash tray re-inserted. However I have kept the stop light indicator and hidden the leds. I have gone back to the normal OD switch - far better than silly logic circuits. Roger Quote Link to post Share on other sites
MRG1965 Posted August 4, 2014 Report Share Posted August 4, 2014 Cheers Roger, make sense now, but I like Graeme's answer too Mark Quote Link to post Share on other sites
tr4head Posted May 5, 2022 Report Share Posted May 5, 2022 (edited) Great info on this page, tho I am 8 years down the road.....seems everyone has angle drive. What about the Tr4 without? The cable goes straight in the gearbox but my new one only barely enters the pinion. How far is is supposed to go in gearbox? My broken cable was in for about 1" and snapped. I pulled out with skinny needle nose and thought the new cable would go right back in. Not. Also. the Speedometer is now a tad difficult to get in and it seems drive cable is a little long sticking out (by probably the amount lost at gearbox). I have a hard time screwing both end caps in with the tension on cable. Finally, would the pinion gear at gearbox have seized breaking original cable and making it hard to line up the new cable properly to go all the way in, assuming its squared off inside and you cant put square peg in the round hole. Any ideas and I would be more than greatful! Cheers. Edited May 5, 2022 by tr4head Quote Link to post Share on other sites
Ralph Whitaker Posted May 6, 2022 Report Share Posted May 6, 2022 9 hours ago, tr4head said: Great info on this page, tho I am 8 years down the road.....seems everyone has angle drive. What about the Tr4 without? The cable goes straight in the gearbox but my new one only barely enters the pinion. How far is is supposed to go in gearbox? My broken cable was in for about 1" and snapped. I pulled out with skinny needle nose and thought the new cable would go right back in. Not. Also. the Speedometer is now a tad difficult to get in and it seems drive cable is a little long sticking out (by probably the amount lost at gearbox). I have a hard time screwing both end caps in with the tension on cable. Finally, would the pinion gear at gearbox have seized breaking original cable and making it hard to line up the new cable properly to go all the way in, assuming its squared off inside and you cant put square peg in the round hole. Any ideas and I would be more than greatful! Cheers. The gearbox end of the cable needs to be free to slide right in, the inner cable is secured in position by the collar at the speedo end, which as you have said is sticking out too far to get the nut on. I would suggest that there is still some remains in the speedo drive hole of the old cable, although I have also come across new cables being slightly too big, requiring a light touch with some emery paper to clean up the square on the end. The speedo drive unit can be removed if it is easier to work on the bench to see whats in there stopping the cable entering. Ralph Quote Link to post Share on other sites
qkingston Posted May 6, 2022 Report Share Posted May 6, 2022 I had same issue with the gearbox end of the cable, required a bit of light filing before it fitted neatly into the drive unit, when I made initial enquiries with TRGB (who supplied the cable), they admitted that occasionally they have to do this on cars they are working on David Quote Link to post Share on other sites
Ocheye Posted May 6, 2022 Report Share Posted May 6, 2022 I had a similar problem. Re-calibrated and reconditioned speedo stopped working. Checked cable and it was perfect, so I checked the angle drive. The remains of the square end was stuck (brazed) in the angle drive with a few wisps of cable remaining. The new cable had been inserted and tightened as a friction fit and it actually worked for 7000 miles. We (John Morrison and I) decided to ditch the angle drive and a longer cable was purchased and a hole in the chassis was relieved slightly to allow the cable and nut to pass through. It works and no pesky angle drive to worry about Andy Quote Link to post Share on other sites
qkingston Posted July 18, 2023 Report Share Posted July 18, 2023 On 5/6/2022 at 10:10 AM, qkingston said: I had same issue with the gearbox end of the cable, required a bit of light filing before it fitted neatly into the drive unit, when I made initial enquiries with TRGB (who supplied the cable), they admitted that occasionally they have to do this on cars they are working on David On the run up to Glamis my speedo stopped working (after 1500 miles of no issues). after checking nothing was obviously loose, I disconnected the speedo end and drove a short distance, the inner cable was not turning. I removed the gearbox tunnel access plate and disconnected the cable and re-connected the speedo end, the speedo needle moved when I turned the inner cable from the gearbox end. I unscrewed the Rt Angle drive and reconnected the cable; turning the Rt angle drive shaft, no movement on the speedo needle. Oddly however, when turning the rt angle drive on its own, I can see the output shaft turning. I purchased the repro Rt angle drive from TR Shop during the rebuild. I'm guessing the Rt angle drive is kaput, any other suggestions? Regards David Quote Link to post Share on other sites
stuart Posted July 18, 2023 Report Share Posted July 18, 2023 1 hour ago, qkingston said: On the run up to Glamis my speedo stopped working (after 1500 miles of no issues). after checking nothing was obviously loose, I disconnected the speedo end and drove a short distance, the inner cable was not turning. I removed the gearbox tunnel access plate and disconnected the cable and re-connected the speedo end, the speedo needle moved when I turned the inner cable from the gearbox end. I unscrewed the Rt Angle drive and reconnected the cable; turning the Rt angle drive shaft, no movement on the speedo needle. Oddly however, when turning the rt angle drive on its own, I can see the output shaft turning. I purchased the repro Rt angle drive from TR Shop during the rebuild. I'm guessing the Rt angle drive is kaput, any other suggestions? Regards David I fit these as the current repros are poor. https://www.speedograph-richfield.com/shop/angle-drives/rgb-2401-series Stuart. Quote Link to post Share on other sites
harlequin Posted July 18, 2023 Report Share Posted July 18, 2023 I recently fitted an angle drive supplied byTR Shop. It lasted 300 miles!!! Failing as I was leaving the Eurotunnel on my way to TRCH@50, just what you want at the start of a 1000 mile road trip, grrrrr. I have ordered a new one from Spedograph Richfield but so far it's been on the way for two weeks! I am beginning to think that a working speedo is not meant to be. George Quote Link to post Share on other sites
qkingston Posted July 18, 2023 Report Share Posted July 18, 2023 It's pretty poor if they are only lasting that long, I'll get one of those ordered from Speedograph Richfield tomorrow; Stuart I assume you've had no problems with them? David Quote Link to post Share on other sites
stuart Posted July 19, 2023 Report Share Posted July 19, 2023 16 hours ago, qkingston said: It's pretty poor if they are only lasting that long, I'll get one of those ordered from Speedograph Richfield tomorrow; Stuart I assume you've had no problems with them? David Nope fit and forget. You will find its a bit more bulky than standard so adjustment sometimes needs to be made to the cover plate but not always Stuart. Quote Link to post Share on other sites
Les Millington Posted July 25, 2023 Report Share Posted July 25, 2023 TR4A. My mileometor works fine but the speedo goes all over the place and is never consistent. I can be doing any speed on the dial in a 30 zone. I'm using the tacho to ensure compliance with speed limits after checking it against an app. Also the tripmeter won't reset. If the mileometer is working does that mean a duff speedo? Les Quote Link to post Share on other sites
Lebro Posted July 25, 2023 Report Share Posted July 25, 2023 It means worn bearings on the spinning magnet part of the speedo, or a build up of dirt on the magnet / alloy disc. Fixable if you are brave enough ! Bob Quote Link to post Share on other sites
qkingston Posted July 25, 2023 Report Share Posted July 25, 2023 Or get Speedograph Richfield to refurbish it, a good service Rgds David Quote Link to post Share on other sites
Les Millington Posted July 26, 2023 Report Share Posted July 26, 2023 Thanks guys, the latter I think, bravery is disappearing with age. Les Quote Link to post Share on other sites
rcreweread Posted July 26, 2023 Report Share Posted July 26, 2023 35 minutes ago, Les Millington said: Thanks guys, the latter I think, bravery is disappearing with age. Les Les - how about going the whole hog and replacing all your instruments with a set of these magnolia faced ones! They have all been fully reconditioned and a bargain at £475 for the whole set. I do have quite a few other small OE instruments for sale which likewise have been fully reconditioned as original with black faces and white lettering - PM if interested for more details - unfortunately no speedos or rev counters Cheers Rich Quote Link to post Share on other sites
earckens Posted July 26, 2023 Report Share Posted July 26, 2023 13 hours ago, Lebro said: It means worn bearings on the spinning magnet part of the speedo, or a build up of dirt on the magnet / alloy disc. Fixable if you are brave enough ! Bob This is exactly what is happening on my speedo (TR4 1964): the cable is fine, cable ends too. Yet when driving, the speedo wobbles up and down; for example at 40km/hr it oscillates between 30 and 50 :)/ Where do I find a view of those magnets, or an exploded schematic? Sending to the UK for repair would be the very last option due to Brexit EU vs Uk transport/taxes/duties/... issues (my car is located in the South of France). Quote Link to post Share on other sites
Lebro Posted July 26, 2023 Report Share Posted July 26, 2023 (edited) I don't have a diagram, but it's not hard to take the innards out of the casing. Remove speedo from car twist the chrome bezell off, & catch the glass, & the metal rim below it. unscrew the trip reset knob. slacken the 2 screws on the rear, & being prepared to catch the dial as it releases, remove the two rear screws. All then will be revealed. the magnet is a big slab of steel which spins as you turn the input cable. small particles of ferrous material can find their way onto the magnet, & if they are big enough, or, if the magnet is wobbling about (loose bearings) they can touch the alloy disk which is under the magnet, & is connected to the needle. Hope that helps Bob Edited July 26, 2023 by Lebro Quote Link to post Share on other sites
earckens Posted July 26, 2023 Report Share Posted July 26, 2023 Hi Bob, thanks a lot for that info, it will help as this is totally new for me. I did find a repair manual meanwhile: "Speedo repair manual" for a TR4 (below) TR4 speedo_repair_manual.pdf Quote Link to post Share on other sites
earckens Posted July 26, 2023 Report Share Posted July 26, 2023 (edited) I just found this video: magnetic speedometer disassemby Not for the faint-hearted EDIT: I contacted the creator of that video, a gentleman in Gloucester, http://magnetic-speedometer-repair.com/ I probably will send the meter to him, after our holiday season here when I can miss the meter for several weeks. Edited July 26, 2023 by earckens clarification Quote Link to post Share on other sites
gloide69 Posted July 26, 2023 Report Share Posted July 26, 2023 I have the same problem with a wavering Speedometer at about the 40-50Mph point. I have tried to investigate it, if I spin the cable with a drill, at the gearbox end of the cable, the speedo needle appears to be stable. So I guess this means the speedo, cable and cable routing are OK and the problem is with the gearbox. I have also checked the dimension of the cable square end verses the size of hole in gearbox drive and there shouldn't be any way it can be slipping. So then I gave up.... Quote Link to post Share on other sites
Les Millington Posted July 26, 2023 Report Share Posted July 26, 2023 Hi Rich I've already got a list of 'essential' upgrades/improvements without you tempting me Not sure about white, I'll have to ask herself, having done over 7,000 miles in the last couple of years, only about 100 have been without my wife, she gets a good shout. Quote Link to post Share on other sites
earckens Posted July 26, 2023 Report Share Posted July 26, 2023 6 hours ago, gloide69 said: I have the same problem with a wavering Speedometer at about the 40-50Mph point. I have tried to investigate it, if I spin the cable with a drill, at the gearbox end of the cable, the speedo needle appears to be stable. So I guess this means the speedo, cable and cable routing are OK and the problem is with the gearbox. I have also checked the dimension of the cable square end verses the size of hole in gearbox drive and there shouldn't be any way it can be slipping. So then I gave up.... Interesting, I had not done this test. I guess I'll have to ask my wife to watch the speedo while I am driving the drill :). Quote Link to post Share on other sites
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