How to dismantle a spedo with trip adjuster rod

[Dougal]

Hi Guys, what is the secret of taking a spedo apart without bending the trip adjuster rod. My one has been broken off at some time and is missing the knurled adjustment knob. I want to replace it but I cannot see how it is dismantled.

Bezzel comes off, Glass comes out, screws removed from the back whats the next step without bending the face or remains of the adjuster rod??

 

[pan]

Dougal,
Send it to Lionel Otto Intruments in Salisbury (Brisbane), they'll fix it!

 

[Bob_Spidell]

I've done it many times, but not recently so memory is a little fuzzy.

Don't recall if you have to take the indicator needle and dial plate off, but it sure makes it easier. If you do, press the needle stop peg in--it's spring-loaded--and let the needle rest in a normal position (vertical). Note the position of the needle--that's your speed calibration. The needle can be carefully pulled off--if it seems stuck then leave it on lest you break it. You'll need a jeweler's screwdriver from one of the little kits to remove the two small screws holding the dial plate on.

The tripmeter reset rod is spring-loaded too, as you probably know. You'll need to push it up as you try to finagle the internal mechanism out. IIRC, it's easier if you remove the bulb holder for the high beam light. It has a tube that goes to the plastic 'jewel' that encapsulates the light from the bulb and makes it more difficult to maneuver the internal mechanism. The bulb holder has two small, copper clips that hold it in the case; carefully press them inward and pull the bulb holder and tube out. It will have a small length of a rubbery tube that makes the final connection between the bulb holder tube and the 'jewel,' it'll either come out with the tube or stay affixed to the 'jewel' or fall off (it's probably very brittle by now).

The rod is two-part; if you still have the bottom part--that would usually hold the knob--you need to remove it to shorten the rod. It should have a tiny roll pin you can push out (think I use one of the jeweler's screwdrivers for a drift).

It's mostly a matter of getting just the right angle on the mechanism and pushing the rod in. If the speedo hasn't been disturbed, there will be a thin metal washer (maybe two), a felt washer and a spring--that's about the size and shape of a ball-point pen's spring--under the rod spring that is used to seal around the rod's hole. Note the arrangement and be careful not to lose them.

BTW, if it's only the bottom section of the rod that is broken you can replace it--see my comment on tiny roll pin--without removing the mechanism from the case. If you need to replace the entire shaft I can't tell you much as I haven't done it, but there will be a way. Remember, these devices were assembled by hand, so can be disassembled as well.

Edit: Substitute 'lens' for 'jewel'

 

[MikeP]

When I've taken Smith's speedos apart I use a pair of needle nose with curved tips to remove the needle. Put them underneath with the tips against the needle center and at 90 degrees to the pointer. Use the face as a pivot point and push the needle off the shaft rather than pulling it. Doing this there seems to be less chance of breaking it as the piece inside the center section is being pushed on rather than being pulled and shouldn't break off the needle.

 

[Rob Glasgow]

Bob, Your explanation is spot on. Your memory doesn't appear to be even a bit fuzzy, at least as far as taking apart speedometers.......

 

[Bob_Spidell]

... now if I could just remember where I put my keys ...

 

[Dougal]

Cheers all, its tempting to take Pans advice, but I'm a glutton for punishment and cant help taking things apart if I can. .....Occasionally I get them back together too.