Trip Odometer Reset Cable

[S30Driver]

In the process of refreshing my instrument lighting, have the tach removed, and cannot release the little screw that holds the trip reset cable to the back of the speedometer.

 

Does anyone know what type of head the screw is?  Have tried mini phillips, slot, small allen hex, etc.  Can't quite see with a flashlight what the screw head is to use the proper tool.

 

Read an older thread where Captain O. indicated that the vent hose could be unplugged to give the trip cable enough length to remove the speedo.  I am worried I won't be able to reattach the hose though.

 

Just need to get to the top speedo lighting bulb, got the bottom one replaced with not too much trouble without removing the speedo completely.

Edited March 14, 2015 by S30Driver

[Zed Head]

Almost positive it's a tiny slotted head screw.  Jeweler's screwdriver size.  Slotted heads are the hardest to find, blind,  Don't take it all the way out, just loosen it and turn it out enough to release the cable, plus a little more so you can get it back in.  There's a tiny hole for the tiny end of the screw to sit in.  You'll know you got it it in if you turn the screw in finger-tight and it locks the cable end in.  Then tighten the screw down.

 

I dinked around with that several times because I never got the screw tip in the hole before I tightened it down.

[S30Driver]

Thanks, Zed

Will see if I can find a jeweler slot & give it a try tomorrow when I have more light ....

[Zed Head]

Forgot to say, I think that I used a small mirror to get a look at the orientation of the slot so I'd have a head start once I stuck my hand in there.

[zKars]

not sure if i want to confuse this but i'm pretty sure its a phillips head. I'm travelling and can't take a look at a spare. The only other slot head screws on a datsun that I can think of are the set screws on the choke knob and fan knob. and maybe the heater control knobs. So what possible reason would that set screw on the trip cable have to be a slot head.... Now I'm confused...

[rcb280z]

I just had mine out recently and it was a tiny philips head screw.

[Zed Head]

Sorry, odds are you guys are right.  I'm certain it was tiny though.  I have one of those little jeweler's screwdriver sets, Phillips and slot, and it was one of those small drivers for sure. 

[rcb280z]

Your right about tiny. Yours may have been replaced with a slotted screw ZedHead. 

[Namerow]

From my '70 Z...

 

Sorry the picture is a bit fuzzy, but you can just make out that it's a Phillips head screw.  Good luck.  Mine dropped down into the back of the IP after I unscrewed it, and I never found it again until I pulled the dash to start crack repairs.

[Captain Obvious]

Two things that might help... First is that the screw LOOKS like a Phillips head, but in reality it's not. It's a JIS (Japanese Industrial Standard) screw that's very similar to Phillips, but slightly different. Most of the time they're close enough that you can use typical Phillips screwdrivers on them without incident, but there are times when a Phillips screwdriver will smear out the JIS screw head.

 

Second thing? If you're just trying to replace the upper bulb and you've already got the tach out, can you reach in through the hole left by the missing tach to get to the top speedo bulb? You might not have to pull the speedo at all?

 

(Also, can you post a link to that thread where I was talking about the cable before? I remember the thread, but can't find it.)

[S30Driver]

Thanks for the JIS info Bruce.  Very helpful.

I found my set of small phillips, PH0, PH00, and PH000 sizes.  Hopefully the 000 will work.

 

On the upper bulb, it is to the left of the high beam bulb, & the wires are fairly short.  No way to get two hands in there and I didn't think I could release the old bulb from its socket and get the new one in with only one hand.

I did get the bottom bulb changed that way, it is to the right of center on the speedo, so easier to reach.  Just barely was able to get my big hands in there.

 

Here is the link from the 2012 thread...

 

http://www.classiczcars.com/topic/45094-speed-o-removal/?hl=+speed

[Captain Obvious]

Glad to help and I hope it does in fact help!

 

So one more detail about the JIS screws vs Phillips. I've not reviewed the mechanical specs for both, but I've found that it often helps to take a small amount of material off the very tip of your typical Phillips screwdriver in order to get a better bite on a JIS screw head. In other words... I've found that Phillips screwdrivers bottom out in JIS screws before they are fully engaged because the tips are "too pointy".

 

With something that small, a couple passes of the screwdriver point across some sandpaper ought to take off enough material to allow deeper engagement. Couple strikes straight across some 320 grit?

 

Thanks for the link back to that thread and the only other thing I could add is that I managed to get the air duct off and back on, so it's at least possible!   So you can wrestle with the screw or you can wrestle with the duct.