Broken Odo gear

[DZGunner]

How do i know which exact size this one is? Pelican parts has a whole bunch, with a couple looking very similar to mine, but with different labels or names. 1987 s4

[MPDano]

Send this pic to Roger at ************

He can sort this out for you.

[gbgastowers]

Originally Posted by DZGunner

How do i know which exact size this one is? Pelican parts has a whole bunch, with a couple looking very similar to mine, but with different labels or names. 1987 s4

FROM ODOMETER GEARS WEBSITE-
Odometer Gears - Porsche - 928 77-95 (Non-US)

Porsche Non-US 928 Odometer Gear
( view PDF instructions )
There are multiple tooth count options that can and will be installed in this odometer. You will need to count the teeth on the old gear before ordering. The outside gear will have 20 teeth, the smaller inner gear between 21 and 29.{If you cannot count the teeth on the main gear then count the teeth of the next gear that it meshes with. If your tooth count is 49: 20x21, 48: 20x22, 47: 20x23, 53: 20x29, 54: 20x30, 56: 20x32}
$25.00

[DZGunner]

The inside gears are grinded off aswell, making this a bit hard

[DZGunner]

nvm i got it, thank you

[Danglerb]

Buying a part like this from some one other than one of the knowledgeable 928 vendors who support our cars for a few bucks saved, may waste 100% of the money spent on a wrong part.

[DZGunner]

its 20/23

[gbgastowers]

Definitely buy from 1 of the big 3. I just wanted to help figure out which one he needs. Counting the adjacent gear teeth is very hard. I counted 6 times and came up with a different number each time. I thing my adjacent gear is 36 teeth inner and 49 teeth outer. This is on a spare 85mph gauge I am messing around with. Gunar

[Xlot]

One tip for counting teeth - put your digital camera in Macro mode, take a clear photo of the gear you're counting, and then blow it up to fill your computer screen.

If you need to, you can add numbers to the picture

(I went through this recently)

[DZGunner]

I just set a flashlight upright and placed the gear on it to keep the entire thing well lit, counted it multiple times and got 23 each time. Part is on the way

Also, does the speedometer have any interaction with this gear? sometimes my speedometer will not work, )like if i hit a big bump or something), its sort of random, but the cure apparently is to just hit the top of the dash until it pops back up to the correct reading, just wondering if this gear has any play in that or if i need to look into some other problems.

[Xlot]

Intermittent speedo is likely poor contact on one of the rivets to the rear of the speedo where the pins join the circuit board.

Careful cleaning and a dab of flux and solder can be done to them to ensure good contact.