73 speedometer problems

**Bob G** · 06-28-12, 08:31 PM

I have replaced the speedo cable, transducier, nylon gear into the trans. the speedometer will work in first gear but when I shift, it stops, sometime as I drive it will start and work fine for hours. Could it be at the dash that the gears are worn. All help will be appreciated. thanks bob.

**Mac** · 06-28-12, 10:45 PM

I had trouble with my speedo which turned out to be related to the adapter between transmission and the speedo cable itself. The end of the adapter that attaches to the speedo cable had popped so it slipped in and out. When it was out, no speedo reading. When it was in, it worked. I ended up replacing the adapter but the ratio is wrong so my speedo is always off. Not an idea solution but it's better than nothing.

-Mac

**Bob G** · 06-29-12, 08:12 AM

Originally Posted by Mac

I had trouble with my speedo which turned out to be related to the adapter between transmission and the speedo cable itself. The end of the adapter that attaches to the speedo cable had popped so it slipped in and out. When it was out, no speedo reading. When it was in, it worked. I ended up replacing the adapter but the ratio is wrong so my speedo is always off. Not an idea solution but it's better than nothing.

-Mac

Thanks Mac I replaced that adapter to, with the correct ratio.There is a small clip that goes into the adapter that fits the speedo end, I replaced that at the same time. So everthing is new from the cable to the nylon 19 tooth gear in the trans.
Thanks bob

**Mac** · 06-29-12, 02:31 PM

Originally Posted by Bob G

Thanks Mac I replaced that adapter to, with the correct ratio.There is a small clip that goes into the adapter that fits the speedo end, I replaced that at the same time. So everthing is new from the cable to the nylon 19 tooth gear in the trans.
Thanks bob

Where did you find one with the correct ratio? Apparently the one for the L82/M20 wasn't common. I couldn't find one with the correct ratio but I must admit I didn't look all that hard.

-Mac

**GTR1999** · 06-29-12, 03:48 PM

Originally Posted by Mac

Where did you find one with the correct ratio? Apparently the one for the L82/M20 wasn't common. I couldn't find one with the correct ratio but I must admit I didn't look all that hard.

-Mac

I have one here out of a 75 L82 M20. 1:.882 ratio, I had another but may have sold it. Those are not too common anymore and run over $100 now.

**Mac** · 06-29-12, 05:04 PM

Originally Posted by GTR1999

I have one here out of a 75 L82 M20. 1:.882 ratio, I had another but may have sold it. Those are not too common anymore and run over $100 now.

Yup, the 1-to-0.882... that's the beastie... I understand the F-Body guys have the same adapter so I'm surprised no-one is reproducing it.

I've been running with the 1-to-1 adapter for a number of years. Instead of looking at the speedo, I watch my Garmin. I have my old adapter which is likely repairable as the case isn't fractured or cracked. I wonder if it would be possible to use the common 1-to-1 adapter but swap the plastic ratio gears and achieve a speedo reading that was close enough for most purposes?

-Mac

**Bob G** · 06-29-12, 05:30 PM

Originally Posted by Mac

Where did you find one with the correct ratio? Apparently the one for the L82/M20 wasn't common. I couldn't find one with the correct ratio but I must admit I didn't look all that hard.

-Mac

I found one at the local GM dealer. the parts manager is very helpful, looked up the parts for me and order the adapter, the ratio was 1:882 part #01565211 got the # of the old one. the part is discontinued but still can be found.the other adapter # are 1565202, 03932220 stamped .7333-A, 03890575 stamped.8319, 03925673 stamped 1.1111-V those are the ratios.When you buy an adapter I think you have to buy a Key for the speedometer to fit the adapter,I did. bob g the adapter I got was 130 dollars.

**Mac** · 06-29-12, 05:40 PM

Originally Posted by Bob G

I found one at the local GM dealer. the parts manager is very helpful, looked up the parts for me and order the adapter, the ratio was 1:882 part #01565211 got the # of the old one. the part is discontinued but still can be found.the other adapter # are 1565202, 03932220 stamped .7333-A, 03890575 stamped.8319, 03925673 stamped 1.1111-V those are the ratios.When you buy an adapter I think you have to buy a Key for the speedometer to fit the adapter,I did. bob g the adapter I got was 130 dollars.

Your parts manager was far more helpful than mine (at the time). He did a search, found it was discontinued and said check the aftermarket.

-Mac

**GTR1999** · 06-29-12, 08:24 PM

yeah you may find one on ebay or carlisle but I haven't seen many of the 882's. If anyone is interested in this one I may consider selling it for $100.

**herminator** · 07-15-12, 11:25 AM

Originally Posted by Mac

I had trouble with my speedo which turned out to be related to the adapter between transmission and the speedo cable itself. The end of the adapter that attaches to the speedo cable had popped so it slipped in and out. When it was out, no speedo reading. When it was in, it worked. I ended up replacing the adapter but the ratio is wrong so my speedo is always off. Not an idea solution but it's better than nothing.

-Mac

Dont worry, your 1:1 replacement will work. Instead of paying $120 for the correct ratio, all you need is to figure what size gear will make your speedo correct and spend $8-9 instead. I forget the formulas now but the guys at Keen parts helped me figure mine out and speedo reads correct now. I think one tooth equals 5mph but I dont remeber if you increase teeth to decrease speedo reading or the opposite...