Dan Cobb

84 Carrera with original gauge. It just quit working on the return leg of my recent road trip. I have found the required part, but cannot locate additional information regarding the repair process.
Is it somehting that I might/should consider doing myself?
I determined that the calibration of the speedo was a bit optomistic (5-7MPH) and I will likely need to correct this issue when/if I upgrade to 16 or 17" wheels.
How would others proceed?
Fix the odometer now and calibrate at a later time.
Fix and calibrate now for the current tire size.
Fix and calibrate now for the future tire size (I belive this would make it read slower thant actual speed).

As always, thanks for any insight.
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DustinTarditi

Did you adjust the trip meter while driving? I understand this to be a leading cause of speedo gear death.

I would not DIY, personally - unless you're comfortable with swiss watch repair, or automatic transmissions... lots of little parts.

DustinTarditi

BTW - if you're cartain that you will get larger diam wheels/tires do it once and get it over with, IMHO.

Ducboy

This is myth and legand. Anyone that has had this gear go relative to the reset is purely coincidental. Mine went with out a reset. I did get the gear and pulled the gauge apart to find a perfectly in tack gear. (this is way out of the ordinary). There is a littel stepper motor in there with the worm gear on it that was sticking. freed it up and it worked great for a week. Then it stopped. I sent it to North Hollywood Speedo. They rebuilt it and serviced the gauge including calibration. I just got car running again this evening, Worked like never before.

Replacing the gear can be a DIY. Opening the gauge is thte easy part. swapping gears is more difficult. There a tech articles on Pelican. Mostly for mechanical speedo, much simpler.

rbcsaver

Dan,
I would suggest sending off to Hollywood Speed and Clock. Oh yeah, in the Posrch lingo of "while you're there, perhaps a gauge face chang to white, or another color that floats your boat.
Seriously, a tough item to fix and I would send it out to them. They repaired my 84's Tach a few years ago and I couldn't be more pleased with the results.
regards,
Steve

Bill Gregory

Dan,

FWIW, I used North Hollywood when I converted my 85mph 911SC speedometer face to the 150mph face. They also replaced the odometer gear, which they said was about gone. Calibration was spot on....refreshing to know that 30 is really 30, 50 is 50, etc.

afinepoint

Not a do-it-yourself job. Leave it to a pro. When re-installing use a bit of armor-all to lubricate the gasket. This will allow you to orient the face once in if needed.

AFP

john70t

It is possible to have larger rims with lower profile tires- but with the overall outer diameter of the wheel/tire combo staying the same. Check the odometer gearing to the 1/4-mile marker lines on the highway, and compare the speedometer to several modern vehicles at several different speeds. The specialty stuff is sometimes better left to the experts.

You could have 2 seperate speedometer units corectly calibrated for each one of the wheels steups.