Inaccurate speedometer

[Triple C]

For some time I have suspected the speedometer on my 1985 925A1 was off. I checked it today against a handy dandy Android App and the speedometer is 7.5 miles slow. When the speedometer shows 40, I am actually going 47.5. Anyone else having this issue? My truck looks like it was cobbled together, tricolor camo bed, desert sand cab and chassis. It isn’t really a problem, just thought I would let folk know in case they need to check.

 

[Derrickl112]

Did you test the app in another vehicle to check its accuracy?

 

[juanprado]

The a1 & a2 with super singles have a speedo gear reducer/adapter. Not sure of the "technical name" to give an accurate reading. I would suspect this gizmo is missing or not working.

 

[rrrr]

The a1 & a2 with super singles have a speedo gear reducer/adapter. Not sure of the "technical name" to give an accurate reading. I would suspect this gizmo is missing or not working.

I agree.

 

[Triple C]

I did check it against a couple of other vehicles. I don't think I will chase that gizmo, I will just adjust my speed accordingly. That does help explain why my front tire came to pieces on recovery. That would have meant I was going about 65-67 a lot of the way and only running about 45 lbs air pressure. I wasn't a member of the site yet and hadn't read the TM's!

 

[Artisan]

My M925A1 is off about 8-9 mph as well.
It is pretty much standard on these trucks I am told.

Get a GPS and look at your spped with that. my new
magellan says I roll at 68.3-4 MPH on a flat road, pedal
to the metal.

It is more fun at about 50 real speed though...IMO

 

[juanprado]

Glenn in KS gets lots of trucks with super singles. He should be able to source one. I think they connect to the speedo and the cable goes to the adapter. I don't have one (mine is plain jane) so double check me but that is what I recall seeing.

 

[Triple C]

My M925A1 is off about 8-9 mph as well.
It is pretty much standard on these trucks I am told.

Get a GPS and look at your spped with that. my new
magellan says I roll at 68.3-4 MPH on a flat road, pedal
to the metal.

It is more fun at about 50 real speed though...IMO

I agree, my truck LOVES 50mph. I am not in a hurry anyway. And Thanks juanprado, Glen is an awesome guy and I am going out there soon but I don't really care about the adapter, I will just adjust. Not a big deal really, just thought some other folk might want to check theirs.