Cleaning oil from speedometer (1 Viewer)

[Eurasiaoverland]

This had me sratching my head for a while - I had oil leaking up the speedometer cable into the cabin, starting from the back of the speedometer and creeping all along the bottom of the dashboard panel.

So the back of my speedometer is covered in oil. Ideally, I would like to clean it up and re-lube the gears with some silicone lube.

What's my best bet for cleaning these parts? I'm not very keep on dismantling the speedometer. I was thinking about spraying it with contact cleaner.

Bad idea? Is it best left alone? I don't think gear oil is very good for plastic parts, though it has probably been on there for years already.

Thanks

EO

 

[Spike Strip]

Plastic safe contact cleaner is probably a good idea. Then if you can find a syringe to inject silicone grease.

I don't know about the diesel versions, but in the gassers, there's a crude speed sensor in there.

I believe the gear oil gets pumped thru the cable when the O ring in the transfer case speedo gear house fails.

 

[Eurasiaoverland]

Plastic safe contact cleaner is probably a good idea. Then if you can find a syringe to inject silicone grease.

I don't know about the diesel versions, but in the gassers, there's a crude speed sensor in there.

I believe the gear oil gets pumped thru the cable when the O ring in the transfer case speedo gear house fails.

Thanks Spike Strip, a syringe sounds like a good idea. I'll try to keep any of it from going into the cylindrical thing on the back of the speedometer - I assume this is a gearbox of sorts?

Speed sensor - do you mean the silver cylindrical thing in the pictures? Or the speedo pickup in the transfer case? If the latter, they are exactly the same diesel and petrol. It's the internal lip seal I think which goes, the O ring is the external seal.

Not sure if petrol and diesel speedometers are the same - I expect they are. Mine (BJ60) says 60 km/h - 637 rpm which is a nice piece of information for Yazaki to give so that we can calibrate spedometer drive and driven gears to final drive ratios and tyre size in order to select the best gear set.

EO

 

[Spike Strip]

1986 FJ60:

If you have the 4-pin connector, the black & blue wires should connect to the reed switch which should be adjacent to the cup that is spun by the speedo cable, In the first photo, I've identified what I think may be the vss reed switch. I can't really tell from your photo. The 2nd photo is of a reed switch. This one came out of security system door sensor but you get the idea. The speedo switch may be different in size but generally they are a little glass tube with a set of contacts sealed inside with a wire coming out of each end of the tube.

An easy way to tell is to connect a continuity tester to the black and blue wires. As you rotate the speedo cable, you should see the tester switch from open to closed four times per revolution of the cable.
View attachment 632603View attachment 632604

 

[Eurasiaoverland]

1986 FJ60:

OK, I never knew that. Mine has no electrical connections whatsoever - just the silver gearbox running straight to the needle, and the worm-gear take-off to the odometer.

As yours (?) has the same, I assume the electronics are some sort of speed sensor to feed into a different function (speed warning buzzer? I know some Middle Eastern 60s had these).

Thanks for the information - really interesting.

EO

 

[Spike Strip]

It's for emissions. The signal is pulsed to the emissions computer logic box.

 

[Eurasiaoverland]

It's for emissions. The signal is pulsed to the emissions computer logic box.

Indeed, diesels do not have that.

 

[dbbowen]

I use technical grade isopropyl alcohol (99.8%) to clean electronics like circuit boards, relays, and stuff like that. Its got 0.2% water content and evaporates completely very quickly. Just dont use it for any skin or medical or food stuff. Its got impurities in it and is only used for cleaning