Speedo Bouncing

[Marty Rogan]

Well the last time I drove the Z (70 240Z) the speedo went spastic on me. When you tromp the gas, the needle bounces wildly up and down. Once you get to a cruising speed it settles down some and bounces in about a 10 MPH span.

Any ideas on this one?

TIA,

Marty

[EScanlon]

Did you recently do some work under the dash? Or maybe on the engine side of the firewall where the speedo cable goes in.

What you're describing sounds exactly like a sticking cable, whether because of lack of grease in the jacket or because the gear that's driving it has lost a tooth.

2¢

[Inf]

What would be a good way to re-lubricate the cable? I have this same problem to a lesser extent. What kind of lubricant do you recommend for this?

[Marty Rogan]

Escanlon,

Well, time wise, I was under there 2 years to replace the master clutch cylinder. Miles wise, it was about 2,000 miles ago. I suppose I could have bumped the cable or pulled on it, but it has not really been a problem till recently.

So what is the best way to lube the cable?

Thanks,

Marty

[carguyinok]

I am not sure if it's the BEST way but.....:nervous:

I pull the cable out at the trans. then feed it (without the gear) up near the firewall. Hold the cable as high above the motor as you can. Take a drill and get a bite on the cable where the gear hooks on. Now as you run the drill drip or spray the oil on the turning cable. One other thing I do is run the drill bolth ways once I have enough oil in the cable case.

All I can say is " It works for me" and NO your drill wont spin fast enough to hurt the speedo.

[Marty Rogan]

Sounds easy enough. What kind of oil do you use?

Marty

[carguyinok]

For the cable I have found that the 3 in 1 oil works well. I have done it with the spray WD40 but found far less mess with being able to drip the oil in rather then trying to spray it.

Another thing

Look over the cable case and make sure it is kink free and that there are no flat spots in the case:stupid:

Good luck, It's a very easy job yet very dirty if the car has had any oil leaks

[kmack]

Last month my speedo started bouncing during an autoX. I was topped out in 3rd and the needle was bouncing between 25 & 55. Then it dropped and worked no more...

I thought the cable broke. Turns out all the teeth on the speedo drive gear (on the tranny) were gone. The little yellow gear was completely flat!

I pulled one out of the spare tranny and voila`, no more speedo troubles.

[shoudt]

I will try these steps but I think my cable is worse off then what I have read. It seems as if a squirrel or something chew through the rubber and the metal wire around the cable. Should I just try to get a new cable?

Does anyone have an idea of how much they go for?

Thanks.

[carguyinok]

MSA has new cables for around $75.00