I have an '88 L8000 with the Ford in line 6 - not that that info has any bearing on the question I'm about to pose nor the answer. Briefly, the electronic speedometer was replaced some time back and never calibrated to the truck. The speedo has 8 DIP switches on its backside and the shop manual indicates they are to be set per specs in the"Parts Service Manual". Nobody at Midway Ford (local heavy truck dealership) has a clue as to what the manual is (or was) and can only say "bring it in and we'll see what we can do". Now I know little about solid state electronics, but I do know that at some point in time a spec sheet was available that would give the switch settings for the various axle ratios, tire sizes, and etc. Anybody out there old enough to remember what I'm talking about and, more importantly, where to find specifications? I have tried numerous other Ford dealers, heavy truck repair shops and speedometer shops to no avail...
If you cant get anything else... Somewhere Ive got a stash of calibration sheets for whatever Speedo Pete and Kenworth use. Let me know and Il try to dig one up and mail it to you. Then you get to spend a half hour of quality time with a calculator and tape measure. LOL
I have a twin to your truck. I could look at the back of mine if it might help.
Any info would help. As I understand it, the DIP switches on the back of speedo are set and then covered up with a piece of tape. My axle is 488/680 and tires are 11R22.5. I think one has to measure circumference, but I doubt that it would be necessary. Can't imagine any other info as sending unit comes off tailshaft of transmission.
I'll check over the weekend. Mine was built with the same ratio and tires.
Overworked, Any info would be sincerely appreciated. Fair warning: the cluster will have to be pulled, but it's not as bad as it sounds. There are 5 screws around the perimiter of the gauge cluster. Once those are out, the whole cluster can come forward. The DIP switches are at the bottom of the backside of the speedo and should have a piece of tape covering them up. It's easier to disconnect the oil gauge sender tube but not completely necessary as a mirror makes the switch positioning visible. There should be 10 switches and they will be either "UP" or "DOWN". I've got the cluster out of my truck now (which renders it inoperable) but have not removed the tape so am only going by my shop manual as to number and positioning of switches. Local dealer (Midway Ford) is evasive as to info and no help. Can't tell if they just don't know how or won't divulge information hoping I'll bring it in at $116.00 an hour. Again, Thank you JR Lesan
If that doesn't work out, I found my info for an Amatek 10 switch speedo. Again, the one used by Peterbilt and Kenworth. But that sheet worked on Volvo and Frieghtliner too.
RZucker, I would appreciate having the info on the Amatek 10 switch speedo. If you would/could email it to me I'm at [email protected] Thanks, in advance JR Lesan
JR,if you can PM me a postal address, I can mail a spare I have. Its about an 8 page booklet.
Pm returned and calibration instruction will be in the mail tomorrow morning.
JR, the info went out in the mail this morning, Hope it helps. I did find find out ford used 2 different 10 switch speedos. Unfortunately the Ametek info will not work if you have a Beebe manufactured speedo. Crossing my fingers for you.
R, Every little piece of information helps. I know that my local dealer has this info: they just won't share it. I think I can find out from Parts Dept who the OEM was for my speedo. Unfortunately there is no logo or name anywhere on it. Hopefully, the instructions you are sending will help me ID the manufacturer. I will keep you advised. Again, thank you. JR Lesan
I'm hoping it works for you, it went out Monday morning.
ColM sorry I haven't had a chance to look at mine. Got a little backed up . but I didn't forget.
Robert, The Ametek instructions arrived today, but unfortunately my speedo is not an Ametek. I was able to punch into the Google search function 'Ametek Speedometer Calibration' and came up with the same form you mailed. (By the way, thank you very much.) I cannot come up with anything for Beebe Electronics or Beebe though. Am I spelling it wrong? Sooner or later I will chase this down.
No, I think you have the spelling right. I've only dealt with Ameteks, so I'm not sure where to look for the Beebe info. And you are welcome, sorry it didn't help.
The way I would approach this, if manuals cannot be found, is to calculate the tone frequency generated by the tone ring at a particular speed and then use a tone generator to set the switches by trial and error until the speedometer reads the correct amount.