Speedometer Tester

[Agatha]

Hi folks - newbie to forum. Will soon be the proud possessor of a Master Speedometer Tester manufactured by Sun. Does anyone know anything about this tool, such as approximate age, history, value, etc. It is listed as Model MST. It works and only needs a minor cleaning. Might also have the original instruction manual. It is a gift from a very dear friend for our 'garagemajal' warming which we hope will be in Spring 2011.

 

[Bruce Lancaster]

I dabble with old Ford speedos (I have no specialized equipment like that) and I know of one book that should help...I know it shows testers and such:

TM 9-1829A Ordnance Maintenance-Speedometers, Tachometers, and Recorders-1944

Right now, I can't find any originals for sale...if you want, PM and I can give you a source for CD version, or google Portrayal Press, which reproduces most WWII tech manuals in paper.

 

[regguy1]

FYI: For a cable driven speedo the SAE standard is: 1000 cable rpm = 60 mph

With this info you can check or correct errors in cable driven speedos.

I use a gps clock vehichle speed at exactly 60 mph and note engine rpm in high gear (1 to1 ratio, not in OD) then I can determine needed speedo gears to achieve 1000 cable rpm at 60mph.

 

[Bruce Lancaster]

And if you need a quicky test to see if a speedo on the workbench is alive and in the ballpark, you can test with a Robertson square bit and a power screwdriver or drill, estimating from the rated RPM of the motor whether the reading on speedo is reasonable.

 

[1restorick]

Sun Speedometer Testers are well built units that use the same drive components as their Distributor Testers. They allow you to spin the speedometer cable drive to various rpms and magnetize and demagnetize the head unit to calibrate the reading vurses published standards. Great machine to have if you enjoy this work.

Rick

 

[steve817]

Sun Speedometer Testers are well built units that use the same drive components as their Distributor Testers. They allow you to spin the speedometer cable drive to various rpms and magnetize and demagnetize the head unit to calibrate the reading vurses published standards. Great machine to have if you enjoy this work.

Rick

Hello Rick, I just saw your post here about the SUN speedometer testers. I just acquired the Master SUN speedo tester and posted to a guy on here that may be able to help with operators manual. I a restoring Mopar gauge clusters and excited about using the machine to really dial in the speedometers. I am learning about degaussing techniques and if you have any suggestions, I'm all ears. Thanks a bunch, Steve in Wyoming.

 

[Milton Shaw]

Without the dyno part of it you cannot check the speed of the automobile, just the head unit. See if you can find one of the DOT speed radars and drive by it a time or two to see if your reading high or low and by how much. Might save you a ticket. Without the dyno part you cannot tell if the speedometer gear in the trans matches the rear end ratio and the tire size. I had an Aunt whose car was showing 55 mph but was actually doing 85 mph because of tire and gear problems.

 

[steve817]

Without the dyno part of it you cannot check the speed of the automobile, just the head unit. See if you can find one of the DOT speed radars and drive by it a time or two to see if your reading high or low and by how much. Might save you a ticket. Without the dyno part you cannot tell if the speedometer gear in the trans matches the rear end ratio and the tire size. I had an Aunt whose car was showing 55 mph but was actually doing 85 mph because of tire and gear problems.

I do understand that the ****** speedo gear, rearend gears and tire size have everything to do with the actual/true speed of the car. I, however, am restoring 68-70 Mopar B-Body Rallye gauge clusters and calibrating the speedometer to factory settings using this SUN Master Speedometer tester. I can dial in the magnetism to set to original factory settings. Once the factory settings are dialed in, the customer will have options to accurately show speeds relative to radar. An option may be adding a Stewart Warner speedo cable adapter to get the speedo to read correctly if a car has modified options (gears, tires, etc.).

 

[steve817]

I dabble with old Ford speedos (I have no specialized equipment like that) and I know of one book that should help...I know it shows testers and such:

TM 9-1829A Ordnance Maintenance-Speedometers, Tachometers, and Recorders-1944

Right now, I can't find any originals for sale...if you want, PM and I can give you a source for CD version, or google Portrayal Press, which reproduces most WWII tech manuals in paper.

WOW! Thanks for the recommendation Bruce! This old equipment...and parts are just plain fascinating to me. I will look for this book and in the meantime, I would like to check out the link for CD version. Thanks for your help. Steve

 

[steve817]

And if you need a quick test to see if a speedo on the workbench is alive and in the ballpark, you can test with a Robertson square bit and a power screwdriver or drill, estimating from the rated RPM of the motor whether the reading on speedo is reasonable.

Yes, I actually use a variable speed, reversible motor that I can spin up to different RPM's (167, 500, 1000, 1500, 2000 and 2500). The RPM is checked using new technology and will be paired with the old school unit. It will be interesting to collect data and compare both old vs new. I have a couple more things to do to the SUN machine before I can start using it.