speedo acting strange..?

Topic: speedo acting strange..? (Read 1011 times) previous topic - next topic

speedo acting strange..?

January 13, 2008, 09:33:26 AM

after i got the thunderbird running with the new trans, i instantly noticed my speedo not working. so i had to drive it for aobut 15 miles, and then i found the connector ontop of the trans (oops) so i plugged it up. the tailshaft is a new one, i dont think the speedo ring was changed, cant remember if it came off, but everything else was swapped in the tail section. it seems to give me a correct reading up to my speed, like if i accelerate it doesnt spin up to 85 then level out. it does fine although its not 1-35 for example, its like 1-4-6-13-27-34-35-36-35. and when i come to a stop the speed drops but i'll sit at a stop sign for 3 sconds at 6mph not going anywhere.

i think i might have to get it calibrated? i've never had to do that, but other than getting it calibrated, how can i adjust it if theres a way?

i might have to take it apart and recount the pressed on speedo gear. THEn if the gears are different i might have to see how i can fix it without dropping the pig back out. (eg not change the shaft)

speedo acting strange..?

Reply #1 – January 13, 2008, 10:14:56 AM

so your problem is
"speedo shows speed while sitting still"?

thats kind of neat, ill look at my shop manual in a while and see what it says.

speedo acting strange..?

Reply #2 – January 13, 2008, 10:31:32 AM

id say WO style that "speedometer has inaccurate readings, shows speed at stop, slow to respond to speed fluctuations.

side note: shows correct cruising speed"

EDIT further clearifcation, it eventually stops showing speed at stops. to me honestly, its like the gear is 1 tooth off or possibly of a different cut (i didnt see it my dad did most of this while i had to work late) i hate it when he works on my car, he just blindly does the job not taking in account for getting it 100% right) or i first descried it like the gear is still rolling like free wheeling like the back axel of a bike (non pedal brakes) but only coming to a stop. it looks like its not ganna rain too much today, i might get out there with a multimeter.

speedo acting strange..?

Reply #3 – January 13, 2008, 01:31:53 PM

the speed slow during acceleration is fairly normal I would think...

The speedo is only updated 6 times a second. First gear in a 5.0so it would easily jump from one number to another...

speedo acting strange..?

Reply #4 – January 13, 2008, 01:39:42 PM

well i know that and was used to it. i mean if you were in 1st gear rev it out full tilt its ganna jump, but you know if you were 1st (never do this dummies) and let off your ganna have heavy engine braking? my speedo would do fine going forward (more like 3 times s seconds now tho instead of the 6 or so, i think it was faster than that tho) when the car decelerates the speedo would hang at the top speed i achived and then if i stopped imediatly, when i stopped i'd prolly see 24-13-6-0 from sitting still. thats the bad thing too b/c when im at 55, hit a 45, hit a 35, in quick succession and i feel like i cant trust it but i know if i cruise a good distance i get my speed. im really picky about my instrumentation, i use it to keep myself from getting tickets, better than any radar ever made.