1986 944 Turbo - odometer works but trip meter not working

[notny41]

So I just bought my white 1986 944 Turbo back from the person I sold it to several years ago. The guy told me that the trip meter doesn't work, but the odometer does. I thought that was kind of funny because on my other 944 that I replaced the gear on, neither the odometer nor the trip meter worked when that gear went out.

I figured I was going to be replacing the plastic odometer gear, so after ordering one and waiting for it to arrive, I pulled my gauge cluster apart. But when I opened up my speedo, I was surprised to see that the gear had already been replaced by the previous owner... Scratching my head I spun the little screw-drive gear and made it go around a couple of miles and the trip meter was working just fine - as was the odometer. So I figured it must have just been something preventing the trip meter from working and now whatever that was had been cleared so I would just put everything back together and put the gauges back in the car and all would be good. After getting everything all back together and the steering wheel back on I tested the reset button to make sure it clicked and reset the trip miles to zero - which it did, but knowing what that sounds like on my other 944, it sounded kind of funny and then didn't sound like it was ever actuating again after that first time. I thought maybe since it was already so close to 00000 that might be why I couldn't hear it again. So I took it for a spin

Again the odometer was working fine but the trip meter wouldn't move... So then I was thinking that maybe the previous owner missed a piece of that gummy gear they replaced and it was somehow wedging itself in the reset mechanism or something. So I pulled it back apart again. This time when I was unscrewing one of the last screws on the back of the speedo I heard the reset mechanism snap back to its normal position. I took the speedo out and looked that mechanism over for a while and couldn't figure out why it would be sticking. It seemed totally fine. So I screwed it back into the cluster and tried moving that plunger down, simulating the reset procedure and after I pulled that plunger down, it stuck in the down position.

I finally figured out that there is this little plastic finger thing that was getting pinched between the reset rod and the metal plate that the solenoid coil mounts to the gauge cluster with.

cluster finger not binding.jpg (297.81 KiB) Viewed 855 times

cluster finger binding.jpg (310.15 KiB) Viewed 855 times

cluster cut piece.jpg (431.54 KiB) Viewed 855 times

cluster cut.jpg (296.97 KiB) Viewed 855 times

I put the speedo back in the cluster and tested it again with my finger and it worked flawlessly.

I reinstalled the gauges in the car and put everything back together, took it for a spin and my trip meter and odometer are working perfectly again. I can reset it and it makes the correct sound now and the trip meter again starts counting miles up afterwards.

Me = happy!

[Tom]

Fantasic post. Thank you! I think you win the new Carpokean of the week award! I can't quite tell from the pictures, but was something else worn down causing those finger to be too long?

[notny41]

Thanks Tom!

I can't figure out why that plastic piece was so long. And I don't think it is a different speedo than when I owned the car previously - unless they were to have gotten the mileage almost exactly to what it had on it. Because the miles on it seem reasonable to what they would have accumulated since I had it before.

It is very puzzling to say the least.

I don't know if this post will help anyone or not but thought I'd at least post my findings.

(you might notice that the speedo needle is bent - I think that must've happened when the PO replaced the odo gear)

[Tom]

The odometer on my test-rig cluster stopped working recently, so I've been meaning to change the gear. My plan is to 3D print one, as is my way, and see how long it will last. I'll look at that one when I do and see if I can figure out why you needed to cut those fingers. Also might just have to design and print a needle remover tool. It's an acquired skill for sure to remove those needles, and acquiring that skill can be hard on needles (ask me how I know).

[notny41]

I have a spare gear if you'd like it, I'll send it to you. Even if it is just to model your print sketch up after.

[NCGermerican]

Not to bring a post back from the dead, but I wanted to show how valuable these older posts can be. I'm experiencing the EXACT same problem (odometer works, trip odo doesn't). I'm looking forward to seeing if the same issue is causing my trip odometer to not work.

[MoeMonney]

Have the same issue on one of my cars as well after a shop sent the odometer to get a new gear.

Good someone found out why it happens! I’ll be fixing mine soon.