Speedometer Calibration and Shops

[Mark Milner]

Someone wrote on here about getting a speedometer calibrated and said they couldn't find a place that did that. I can't find the original message to respond to, so here is the info.

Many shops are hard to find. Too many people equate speedometer repair with speedometer fixing (setting the odometer to a lower number) and so they keep a low profile. However, ask at real parts stores (Joe's Auto Parts, B&J Auto, etc.) instead of the chains and odds are you will find one local. Also, try asking local independent mechanic shops.

Another way is to go to Yahoo and enter speedometer and repair and you will find a large number of places appear.

There is nothing illegal about having a speedometer repaired, although when asking how to find a speedometer shop, people assume that is what you are trying to have it "fix", not repaired.

[Duke W.]

Re: Speedometer Calibration and Shops

Just look up "speedometer" in your local yellow pages. There are three in mine, and I've done business with two of them.

In addition to doing speedometer and tachometer (mechanical or electric) repair, they have a set of rollers to calibrate your speedometer, and if necessary, can setup a Stewart Warner adapter to bring the calibration into tight tolerance, or change the head gain as I explain, below.

When I had the tach and speedo in my SWC inspected, I had them reset the odometer to zero. When the speedometer head in my Mercedes was replaced under warranty, the dealer sent the speedometer out to one of these shops to have the odometer set to the mileage showing on the original.

My Cosworth Vega has tires that have five percent higher revs per mile than OE and rather than installing an adapter, I had them recalibrate the speedo head. They do this by changing the magnetic flux, and it alters the gain by a constant percentage across the range. The Odometer still reads high, but the speedometer is right on. To correct the electric tach error, which read high in the upper rev range, they removed and reinstalled the needle to make it dead accurate at 7000 revs. The tradeoff is that it reads 100 revs low in the midrange and 200 low at idle, but accuracy in the upper range is most important.

Duke

Duke

[Mark Milner]

Re: Speedometer Calibration and Shops

Duke, I believe he was in the Boston area and said he couldn't find any shops there. I assume he had looked in the Yellow Pages.

However, a search on Switchboard.com for Boston and business type "speedometer", I find two, although at the same address.

Accurate Speedometer & Clock Serv Inc
10C Roessler Rd
Woburn, MA 01801-6208 Phone: (781) 935-9977

Model Electronics of New England Ltd
10 Roessler Rd
Woburn, MA 01801-6208 Phone: (781) 935-9977


Usual disclaimer: I'm not connected with or profit from them in any way.




Speedometers on Switchboard.com

[Joe T.]

Re: Speedometer Calibration and Shops

it was me, i live in amherst, i asked a car dealer and he told me about two shops in town that calibrate speedometers, they aren't listed in the yellow pages under speedometer repair, thanks for the help, joe