unit91

I have a 68 200 6-cylinder with C4 auto tranny. How do I determine if I need a left handed or a right handed speedometer gear? Also, is there any maintenance, lubrication, etc., that I need to do to the actual speedometer, or is that a professional job?

Rat fink

Do you have a speedo gear in it now? if so pull it and look at it. If not go to your ford parts department.
After installed there is no maintenance, the gear gets lubed from the trans fluid.

2+2GT

All 3-speed, automatic, and T5 transmissions use a RH gear. 4-speeds use a LH gear. Mixing them can be bad.

The Glazier/Nolan catalog lists them by application and tooth count, making it easy.

G06547 3-speed manual, automatic, or T5 cable Gear, 16 teeth
G06548 3-speed manual, automatic, or T5 cable Gear, 17 teeth
G06549 3-speed manual, automatic, or T5 cable Gear, 18 teeth
G06550 3-speed manual, automatic, or T5 cable Gear, 19 teeth
G06551 3-speed manual, automatic, or T5 cable Gear, 20 teeth
G06552 3-speed manual, automatic, or T5 cable Gear, 21 teeth
G06553 4-speed manual cable Gear, 16 teeth
G06554 4-speed manual cable Gear, 17 teeth
G06555 4-speed manual cable Gear, 18 teeth
G06556 4-speed manual cable Gear, 19 teeth
G06557 4-speed manual cable Gear, 20 teeth
G06558 4-speed manual cable Gear, 21 teeth
G06559 4-speed manual Gear, inside transmission, 6 teeth
G06560 4-speed manual Gear, inside transmission, 7 teeth
G06561 4-speed manual Gear, inside transmission, 8 teeth
G06519 Snap Ring Retainer secures 4 sp gear to output shaft
G06520 Ball Retainer 4 speed speedometer drive gear

Here's what happens when you use the wrong gear:

Rat fink

2+2
That was kind of my point, there are to many. take it off and go to the ford parts department.

unit91

what about the actual speedometer gauge in the instrument cluster....any lube required there?

2+2GT

A little gun oil on the shaft is all the speedo needs.

As for the L/R thing, it's simple: You got a 3spd/auto/T5 or a 4 speed? All 3spd/auto/T5s use a RH gear, all 4-speeds use a LH gear. Since you have a C4, that narrows it to RH. Now all we need is your rear axle ratio and rear tire size.

It's one of these:

G06547 3-speed manual, automatic, or T5 cable Gear, 16 teeth
G06548 3-speed manual, automatic, or T5 cable Gear, 17 teeth
G06549 3-speed manual, automatic, or T5 cable Gear, 18 teeth
G06550 3-speed manual, automatic, or T5 cable Gear, 19 teeth
G06551 3-speed manual, automatic, or T5 cable Gear, 20 teeth
G06552 3-speed manual, automatic, or T5 cable Gear, 21 teeth

Now, almost every 200 C4 I've seen had a 2.80:1 rear. Assuming you have, say, P195/75R14 tires, and the typical 7 tooth gear machined into the output shaft, you need 16.49 teeth, so you'll need to use a 16 or 17 tooth cable gear. Naturally, you'll want to check your, trans, diff, and tire sizes, this is only an example.

Rat fink

You can remove the speedometer connection from the speedometer case in the instrument panel, The cable will pull all the way out, your cable is 40+ years old so I would wD40 the entire cable. If it was < 10 years old I would say don't do anything to it.

KMatch

Wd 40 is temporary. We used to use a tube of di-electric grease in an orange tube from Napa. It's been many years since I've done any this way (GM dealer tech for many years), but that stuff was the ticket. I recently greased mine with bearing grease, and just a in the old days of doing the same, it bounces at lower speeds. The dielectric was always a bit better and longer lasting.

Rat fink

WD40 is not temporary if it is sealed, which it is. Grease will make the needle jump. If your going to use any kind of grease use the di-electric grease
and sparingly.

KMatch

I really HATE false information. The speedo cable isn't sealed air tight (which is the only way to keep wd from evaporating in a day) and even if it was, wd has no place here unless you want to be sure it's good and clean. Light grease just so happens to be what the factory shipped them with but once they start to show wear (jumping, for instance, due to kinking and binding) it's no longer a good fix although it's better than dry.