My speedo is stuck at 100mph (I don’t know if this was the speed it was doing at the time, it’s been like that since I’ve had it).
I’ve taken it out (I’m replacing the dash anyway) and I’m now considering whether to prise the bezel off and have a crack at repairing it myself or send it off to an expert.
Has this problem happened to anyone else? And more importantly were you able to repair it easily? I’ve attached a picture of the speedo, you can’t see the dead woodlouse in the picture, I’m assuming it wasn’t fitted as standard!
It happened once to my rev counter. I gently tapped the gauge with the rubber back of a screwdriver: tap, tap, tap, and the thing returned to its position. Yours have been stuck for a while so maybe this is not going to work.
I had this problem. I fixed it by taking my foot off the gas.
Seriously, you can remove the bezel by rotating it until the tabs clear each other. Don’t pry it off. Obviously something is binding and it should be evident once you look inside. Best of luck.
While I’m at it I’ve also had a problem removing one of the wires from the back of the rev counter - see the picture.
I don’t want to tug the entire thing off but I don’t know if the inside bit comes out or the whole plastic surrond comes off with it. I think it’s just the inside bit.
Worst comes to the worst I could just cut the wire and use a connector to re-attach the 2 ends but this seems like a slightly ham-fisted way of going about things.
There is an excellent article By Anthony Rhodes on the web entitled"" Repairing Jaeger & Smiths Speedometers"
Its well worth looking for, I found it quite helpful
As regards opening the unit you will find that the bezel is a VERY tight fit, the rubber seal expands with age, I resorted to a little prising.
Removing the trip meter reset and restoring it requires 3 hands
Try twisting the body in your hand to see if you can get it moving and or put a drill with a bit o squared rod in the back and give it a spin each way
Neil
I had a similar problem with my speedo, rotate the bezel as stated in other posts and lift off the glass, the internals are held in by a couple of screws, once out investigation will reveal your problem - mine was the spindle was just full of muck, and needed a bloody good clean. Yours maybe different, but there’s not much to them really. Practical Classics here in the UK have been running a " how to strip your instruments down" in the last two issues - may be worth trying to get hold of the copies. ( When I say instruments I mean your speedo not your trombone.)
I’m late to the party so you’re probably done by now, but while you’re in there, you can do some simple maintenance to keep from having to do it again.
Outside of shunts and whatnot bending the bits, what makes these things go bad is dried grease, usually in the odo area or right where the cable drive enters (it’s a brass sleeve bearing and binds up with age.) If you:
clean off all of the dried grease
make sure all of the parts move freely, especially the cable drive
re-lubricate (I used a light oil followed by spray white lithium (don’t overdo it!)
Assemble carefully and you’ll likely be quite pleased with the results. My speedo reads within 1-2 mph of my GPS throughout the normal speed range, better than the one on my Toyota. My initial symptom was jumping needle. Same for my spare. I suspect Smith’s prided themselves on accuracy.
Note that the way these work is that the drive spins a wheel with a magnet on it. concentric to that wheel is another carrying the needle. The faster it spins, the better the magnet does at dragging the needle wheel against its spring.
The concentric wheels can come into mechanical contact if dropped or if the car’s in a wreck. If this is your problem, you’ll see or at least feel the binding and all you have to do is CAREFULLY straighten the bits so they don’t contact each other anymore.
Note that you can do nasty stuff like zeroing the odo and this takes more disassembly. Outside of the ethical issues (which on cars this old probably mean little), you’ll dramatically increase the effort/return ratio if you go this route. I’ve limited my attention to the odo to making sure the parts move freely and are properly lubricated.
Others send these things off to rebuilders with large quantities of cash and achieve mixed results. I’ve rebuilt several across Triumphs and Lotuses and can’t see why anyone would pay large sums to have it done spottily. It’s no more difficult to get right than most other Lotus tasks.