hey i just bought a 72' 240z and im new to these cars. my speedometer doesnt work! i need it to pass safety any one know why i wouldnt work? all my other instruments work

Likely to be a broken drive cable.

You will need to disconnect the cable from the speedo and the transmission to verify that the inner cable is intact and in fact turning freely.

Broken inner will require a new cable or at least a new inner.

If all is well there, you will need to check that the speedo drive pinion in the transmission is not stripped.

Stripped gears will need a new drive pinion of the same tooth count as what is fitted.

If all is good there, there only remains a faulty speedo.

thanks alot but whereabouts do i start looking for these things ? im a newbie ahah. does this mean i need to take the dash out to get to the speedo?

Welcome to the site - to respond to your question "where to start" I would begin with the search feature. There are a lot of talented and smart folks on this site that take pride in their cars and knowledge. Odds are any challange you are facing has already be documented and resolved. Try the search method first - if you are still questionable - post out to the group to get your best resolution

By the way - don't take that dash out until you have searched for your issues.

The drive pinion is located on the RHS of the rear extension housing of the transmission.

You should see the speedo cable screwed into it.

You should be able to get to the rear of the speedo and unscrew the cable nut with everything still mounted in the car.

If your hands are too big you might have to enlist a smaller person:ermm:

The nut is circular and knurled so it is easy to grip and undo.

As Nissanman said, you can get at the speedo cable without taking out the dash .Tight but it is possible.

Don't remove the dash just for this.

As Nissanman said, you can get at the speedo cable without taking out the dash .Tight but it is possible.

Don't remove the dash just for this.

I have removed the speedo cable from my 280z twice once with the dash half way removed and once with it installed. The second time I was successful but my hand came out bloody (I think I am getting used to this now working under the dash I keep a supply of bandages on hand). No joke.

Yes to the grazes. A couple of plasters is all you will need. Make sure you unscrew the nut the correct way, and don't overtighten it.

Brian

thanks travel'n man. ill look around the site and thanks everyone else! ill give it a go today and report back hopefully with good news

If you can get under the dash with your head and look up at the back of the Speedo you'll see something that screws to the back of the speedo that definitely looks non electrical.....

Or take it loose from the tranny end and pull the cable out if it's broken it'll A. be short and B. be frayed on the broken end. If it's broken and both pieces don't come out the bottom end then take the housing loose from the speedo and pull the remainder out from above.

Are cables available from NISSAN? I had a 510 cable made at a speedo shop here in Salem. Not the housing just the cable and then I gave the damn thing to my brother in law..... Last of the nice guys I guess....

Funny, I was putting my car back together this past weekend and I noticed that my speedometer wasn't reading when I was going forward but it did wanted to read when I was driving in reverse. I took the speedometer out and made sure that the cable was push in all the way in, jack up the car and made sure that the cable that goes in the transmission was connected correctly and everything was fine so finally I started to mess with the actual speedometer itself. My problem was that inside the speedometer where the needle is I had to jump a little bar that didn't allow the speedometer to read when the car was going forward. (hard to explain in words) once I did this the speedometer worked fine. Hope this helps.

I don't know about the LHD, but for my RHD S30, I just remove the tach meter (which is simple to do) and then you can get your hand in to the back of the speedo.