Willcox: Speedo Question
Thread Starter
Racer
Joined: Jul 2007
Posts: 444
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From: Roselle IL
Willcox: Speedo Question
Last year my speedo indicated about 8 over at 40 MPH (It had the blue gear which should work with my 3.73 rear end). When I rebuilt the trans over winter I bought the Red gear from your outfit to counter-act this discrepancy. Now that I have it running again it still reads around 8 over. I am beginning to think that my speedo is out of calibration or my cable needs oiling.
Any thoughts?
Any thoughts?
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,850
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Interesting, what gear (how many teeth) do you have on the drive gear?
On your car, the drive gear should be a 361002 7 tooth green gear.
In some instances changing only one tooth will not make as drastic of a change and this depends on which drive gear is in the transmission and especially if you have an 8 tooth gear. You might try one more tooth before pulling the speedo out of the car. Just a thought!
Is the speedo reading correct at any other speed? Are there any other symptoms such as squeaks, tinning noise, rubbing noise?
On your car, the drive gear should be a 361002 7 tooth green gear.
In some instances changing only one tooth will not make as drastic of a change and this depends on which drive gear is in the transmission and especially if you have an 8 tooth gear. You might try one more tooth before pulling the speedo out of the car. Just a thought!
Is the speedo reading correct at any other speed? Are there any other symptoms such as squeaks, tinning noise, rubbing noise?
Thread Starter
Racer
Joined: Jul 2007
Posts: 444
Likes: 0
From: Roselle IL
The gear inside the trans is Green. I thought this was the 7 tooth, but not 100% positive. I have not been able to tell how far off I am at other speeds. The radar I drove past is in 35 MPH zone. I can try to have someone drive next to me on the freeway to see how far off I am at speed. Based upon my couple of drives on the freeway, I am guessing that I am in the neighborhood of 10 MPH high.
I have not noticed any noises, however, it is pretty loud without the hood and the exhaust that I have. The needle doesn't really bounce much, although it is not rock steady. I would have expected one gear to give me at least a few MPH. I vaguely remember the red being 2 jumps from the blue, but can't recall. You would know better.
Any other thoughts?
I have not noticed any noises, however, it is pretty loud without the hood and the exhaust that I have. The needle doesn't really bounce much, although it is not rock steady. I would have expected one gear to give me at least a few MPH. I vaguely remember the red being 2 jumps from the blue, but can't recall. You would know better.
Any other thoughts?
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,850
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
To explain this better to you, the speedo needle is driven by a magnetic charge in what is termed the first worm and magnet. This is what is driven by the speedo cable and makes the needle move.
The needle is attached to a speed cup that has a spring on it and the tighter the spring is twisted by the speed cup the more resistance is put in to the speedometer. This resistance is adjustable, but what you have done should have made a change on the entire spectrum of the speedo.
Are you positive of your speed? I would check it against a GPS or a late model car! Try something to check your speed at different speeds on the speedometer face. As a general rule of thumb one tooth is five MPH, but in some cases it’s not that drastic and may only change a few MPH.
If you test it again, I still think you might try going one more tooth.
Willcox Inc
The needle is attached to a speed cup that has a spring on it and the tighter the spring is twisted by the speed cup the more resistance is put in to the speedometer. This resistance is adjustable, but what you have done should have made a change on the entire spectrum of the speedo.
Are you positive of your speed? I would check it against a GPS or a late model car! Try something to check your speed at different speeds on the speedometer face. As a general rule of thumb one tooth is five MPH, but in some cases it’s not that drastic and may only change a few MPH.
If you test it again, I still think you might try going one more tooth.
Willcox Inc
