Maybe not the “odometer gear?”
07-22-2022, 01:20 AM
#1
Rennlist Member
Thread Starter
Maybe not the “odometer gear?”
Hi all...
So my odometer (both the trip and overall) just crapped out. I know the plastic gear is a common culprit... but something feels a little off and I have doubts. Before I take out my instrument cluster (again), I thought I’d pose a question to all of you.
Pressing the trip odometer reset button... reset the trip odometer. It won’t accumulate miles... but pressing it again does produce a slight “jiggle” in both the trip and regular odometer. I wouldn’t think this would happen if the gears were stripped?
Anyone have any suspicions/insights on what to look for (other than the gear?)
Thanks as always.
So my odometer (both the trip and overall) just crapped out. I know the plastic gear is a common culprit... but something feels a little off and I have doubts. Before I take out my instrument cluster (again), I thought I’d pose a question to all of you.
Pressing the trip odometer reset button... reset the trip odometer. It won’t accumulate miles... but pressing it again does produce a slight “jiggle” in both the trip and regular odometer. I wouldn’t think this would happen if the gears were stripped?
Anyone have any suspicions/insights on what to look for (other than the gear?)
Thanks as always.
07-22-2022, 05:59 PM
#4
Unaffiliated
The trip odo reset in a late 944 is a strange thing. The button you push up in the dash is an electric switch, and behind the odo is a sort of heavy cylinder shaped magnet in a tube that slides and creates the linear energy in the dash to push a 'heavy" mechanical reset, often breaking really crappy old gears.
You might have seen that already last time you were in there, but for me once I opened it up and looked how it works (or does not work) it made sense. When that magnet actuator slides it makes a very unique thunk sound in the dash I've not heard elsewhere, and I'm quite sure it is the very normal cause of the "slight “jiggle” in both the trip and regular odometer" that you describe. If you haven't done the gears already that is your issue, they are all 30+ years old and that part didn't have a chance even before it got brittle as toast. I found it surprising easy to do and I cleaned up the instruments while I was in there. Read Clark's garage for a how to and parts to be delicate with.
Hope this helps
You might have seen that already last time you were in there, but for me once I opened it up and looked how it works (or does not work) it made sense. When that magnet actuator slides it makes a very unique thunk sound in the dash I've not heard elsewhere, and I'm quite sure it is the very normal cause of the "slight “jiggle” in both the trip and regular odometer" that you describe. If you haven't done the gears already that is your issue, they are all 30+ years old and that part didn't have a chance even before it got brittle as toast. I found it surprising easy to do and I cleaned up the instruments while I was in there. Read Clark's garage for a how to and parts to be delicate with.
Hope this helps
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Millermatic (07-22-2022)
07-22-2022, 08:16 PM
#5
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Thread Starter
I have an arguably irrational love for that reset switch. Such a strange/wonderful/stupid engineering/design solution.
I’ll take the cluster out this weekend. The odometer didn’t work when I bought the car. I thought I’d find a broken gear when I overhauled the cluster as part of my dash rebuild... but didn’t. Magically, the odometer worked when I put it back together. At least for the last year. I’m curious to see what I find. I’m hoping it’s not little pieces of broken plastic. Then again... at least that would be definitive.
I’ll take the cluster out this weekend. The odometer didn’t work when I bought the car. I thought I’d find a broken gear when I overhauled the cluster as part of my dash rebuild... but didn’t. Magically, the odometer worked when I put it back together. At least for the last year. I’m curious to see what I find. I’m hoping it’s not little pieces of broken plastic. Then again... at least that would be definitive.
07-22-2022, 11:36 PM
#7
Unaffiliated
I'm telling you from experience the problem gear will be so tattered you won't be able to count how many teeth it had,
and to replace it you will have 2 choices and no clear guide to which year had which gear.
Perhaps your PO had the gear done but they bunged it up somehow. When reassembling it is possible to get a gear backwards.
and to replace it you will have 2 choices and no clear guide to which year had which gear.
Perhaps your PO had the gear done but they bunged it up somehow. When reassembling it is possible to get a gear backwards.
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07-23-2022, 07:56 PM
#11
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Thread Starter
Speedometer works fine. It’s an 86… so no cable. Recently (unnecessarily) replaced the sending unit. I thought it was bad since my speedometer was reading 20mph slow. Turns out the needle just needed to be repositioned. Felt dumb about that one…
I’ll try to get around to taking it out tomorrow.
On the plus side… I just made a seven-hour trip in the car to pick up my son from summer camp this morning. And it worked great! (Except for the now even less accurate odometer).
I’ll try to get around to taking it out tomorrow.
On the plus side… I just made a seven-hour trip in the car to pick up my son from summer camp this morning. And it worked great! (Except for the now even less accurate odometer).
07-26-2022, 12:26 AM
#12
Rennlist Member
86 has one cluster, not individual gauges, correct?
I bought my replacement gears from this company who had a great writeup:
odometergears.com
https://www.odometergears.com/howto/...ear_Repair.pdf
I bought my replacement gears from this company who had a great writeup:
odometergears.com
https://www.odometergears.com/howto/...ear_Repair.pdf
08-03-2022, 05:15 PM
#13
Rennlist Member
I replaced the circuit board with a good used and it worked like a champ. Easy job and not expensive at all.