Electronic speedometer... broken gear in transmission

[cometcyclonemk]

So....


With the help of you guys I figured out that the speedometer gear in the transmission is the cause of non-functional speedometer... and while I don't really have the time or the tools while down at school to pull the transmission out to replace it, I noticed a post about converting to an electronic speedometer... Is this just a sensor that connects where the cable does (meaning I still need to pull the tranny) or something else? What all is required to change over, and what are the advantages of doing so? Would the speedometer be adjustable / more accurate etc?


Thanks,

Mark

[Mr. Pink]

You shouldn't have to pull the transmission to replace the broken gear....if you can get it out through the speedo cable hole. It is located on the driver's side of the transmission just before (in front of) the shifter. Jack the car up and crawl underneath and follow the speedo cable. The gear is held in by one bolt. Replacing this gear would be A LOT cheaper and easier then converting over to an electronic gauge.

You'll have to reuse your speedo gear with the new sensor required for the electronic set-up anyways.

[THESVOTRUST]

Both systems rely on working physical gears (on the tailshaft/and the sensor)

So if your tailshaft DRIVE gear is junk-remove the tailshaft and replace.
If that is the case there is a good chance that the driven gear (the one talked about above) is junk too!

Converting to "electronic" speedo seems like the hard way to do things.
(and probably more expensive)

Mark
P.S. Dont' forget the clip on the tailshaft gear or you will be doing it again!

[cometcyclonemk]

Yeah I already determined the drive gear is the culprit - I pulled the cable from the transmission - the gear on the end looks good and spinning it results in a speedometer reading, but from reading another forum I understood that the transmission had to be pulled and the tailshaft removed to do the job.

Even so, what all is required to do the electric speedo, I believe you need a later model computer - I'm running an LA3, but what else is done? Is an aftermarket guage used or is there a later model ford option etc? Is it still calibrated via a gear change or is there a more accurate method (of course anything would be more accurate than my current steady reading of 0...)

While I'm blabbing... What is the best way to determine what gears you have? I know the tape on the drive shaft gets you close but is there a better method? I ask because my 1984 Issue of Road and Track states 2580rpm in 5th at 60. Doing 65 (as verified by my parents known accurate speedometer) with my larger diameter than stock tires I'm running almost exactly 3000rpm.

I apologize if this should be in the drivetrain section....