1973 Datsun 620 speedometer

[Angel_Legion]

What's up guys I'm trying to fix my speedometer. Does anyone have any information on how to do this it would be greatly appreciated.

[flatcat19]

Maybe a better description is in order.

[banzai510(hainz)]

WTF!!!!!!!!

2 things  does the odemeter still turn if the nnedle don't move. Then the cable is fine . Otherwise the cable is most likely broke.

 

you have to pull the instrument cluster and unscrew the cable at the trans. most times they break near the trans and you can pull right out.

 

see if a cable is avail from Nissan. I use a generic square cable but learn how to fix this over time.  But I bought spare 521 cabel and just ezer to install quickly.

[racerx]

When you do install the cable just make sure it's not hitting the exhaust.  Did this one time and burned the skin of the cable. 

[datzenmike]

Yes, if odometer is still turning the cable is fine and the problem is the gauge itself. Remove the gauge cluster by loosening it forward and reaching up behind to unscrew the cable. Take a look, can't hurt and you may find the spinning cup that turns the needle by magnetism is stuck, or jammed. Try and fix.... or replace with another. Only real source for one will be from a junked 620 or try our classifieds for a member that has one.

 

Otherwise the cable is the most likely cause. They are easily caught on road obstructions and torn open. Water and dirt get in and if they don't jam or seize, water freezes them solid in the winter and the transmission just twists the inner cable till it breaks. Visually look for kinks or damage to the cable on the under side of the truck. If the damage is visible go straight to replacing it. Loosen the transmission end with vice-grips and unscrew. the cable should be clipped every few feet to the body or frame to keep it safe, so release these tabs. The gauge end fits through a rubber grommet in the fire wall so carefully pry it out and extract the other end. Replacement is the same as removal. Note that the transmission end of the inner cable has a ferule crimped on that only fits the transmission in one position so that  it turns.

[Datfish]

My truck is down with spun rod brgs, so rebuilding, but...my speedo would slowly climb, til I was reading like 100 going 30, I think it rotates all the way around..is there any hope without finding another meter?

[datzenmike]

Take apart. Inside is a spinning cup and a magnet...

[Angel_Legion]

its not the cable guys I took everything off and the cable was just fine it the part that Im talking about. might not even be called that.

[Angel_Legion]

its the spinning cup that is damaged.

[flatcat19]

Pics...the pinion sleeve that keeps the cable ferrule in the transmission?

[Angel_Legion]

It's the speedo pinion

[Angel_Legion]

Where can I get a 16 tooth speedo pinion or does it have to be 16 ?

[flatcat19]

Lots of threads about sourcing the proper speedo gear.

[datzenmike]

its the spinning cup that is damaged.

 

 

It's the speedo pinion

 

Well it can't be both, so a picture is in order. I believe yours will be the longer one on the left???

 

 

Pinions

 

 

Cup

[Angel_Legion]

Yep it's the pinion where can I get one and does it really matter if it's a 16 tooth or can I put a bigger one on?

[Ron1200]

Maybe this will help... http://community.ratsun.net/topic/59563-speedometer-gear-assistance-needed/

 

Try the Nissan dealer... It worked for me.

 

[datzenmike]

Where can I get a 16 tooth speedo pinion or does it have to be 16 ?

 

If your speedometer was accurate then certainly you need the exact same number of teeth. Things that can affect the speedometer readings are changed differential ratios and larger or smaller diameter tires. I suppose if the transmission was swapped from another vehicle and the pinion wasn't swapped also then it would read wrongly.

 

32703-22000 is the correct 16 tooth gear only. Besides the early 620 thew 16 tooth gear was also used (among other gear sizes) in the 311 Roadster, 510, 610 and 710s Different numbers of teeth were used to reflect the different differential gears used in sedans and wagons, tire sizes and options. For the '73 620 there was only the 16 tooth used.

 

Only way for this gear to be crushed is someone twisting it to install or remove. Make sure you slide in straight using the key slot as a guide.

[Angel_Legion]

I couldn't find it guys can anyone else help me get this part?

[datzenmike]

You count the teeth? What color is the plastic? Yellow is 16 tooth. The Nissan dealer... did you try them and that part number??????

[Angel_Legion]

It is yellow so I know for sure that it is a 16 tooth. I didn't physically go to the dealer I just checked on there online store.

 

Start a classified ad here on Ratsun..... http://community.ratsun.net/classifieds/category/5-drivetrain/?sort_key=date_added&sort_order=desc

[datzenmike]

Online store probably isn't going to bother listing parts that old and obsolete. There may be one sitting in some dealership parts storage. Suggest to them they send an e mail to all dealerships looking for one.