McToy

Hi all, had posted the below 2 days ago but wondering if it was in the correct forum so here I re-post on the correct forum hoping someone has any clues...

Hi all, I have a late 85.5 944 that the speedometer isn't working on. So I'm thinking no big deal, let me check the connections on the Speedometer impulse sender at the transmission, worst case buy a new one and swap and that should solve the issue, right?
Well, I just got under the car, found the cable connector hanging in the air not plugged into anything...hmm... so then I check where the impulse sender is supposed to be ...and again, nothing.
Here's the mysterious part: I stuck my phone in there to snap a pic and the hole that you see is where the impulse sender is supposed to sit but:

It looks like neither the sender fitting nor the yellow plastic speedo drive piece are there?? OK, but what's really throwing me off is when I look online at the sender fitting pictures (the metal fitting that holds the plastic speedo drive gear in place) they show the fitting has a thread and as you can see in my picture there is no thread at all where that fitting is supposed to screw into??
Here's a picture of the sender fitting, the top section is what's supposed to screw into the sender hole:


Now I'm thinking maybe the PO had swapped an early transmission into my car? But then the hole for the sender wouldn't be there at all...
Anybody any clues how I get to fit the speedometer impulse sender onto my transmission? Any tips that save me from dropping the transmission would be greatly appreciated.

Tx,
Ralph

dme

Just to be clear, this is the location you're looking at?

McToy

Hi dme, correct, drivers side of the transaxle, see some better pictures below.

dme

sure looks like there has never been anything installed there. Any chance, your car being an 85 that it still has the sensor up with the front left wheel? Just a total shot in the dark.

McToy

I thought that too but then everything else on that car is 86-style including the cockpit with the new dash which has no provision for the old style operated speedometer as far as I know...
I'm really beginning to think this is not the original transmission... Is there such a thing as a pre-85.5 transmission that only has a fake hole where the sensor is supposed to be? From the pictures of early transmissions I've seen on the web there was nothing like the hole i show in my pictures above at all.

McToy

Did more digging online...ok I'm now 99.9% certain that the PO swapped an 84 transmission into the car... just came across a youtube video of an 84' transmission removal that looks just like mine with the hole...



oh boy, so now I need to swap a perfectly fine transmission just to get the speedometer to work
At least the mystery is solved and you'll see a write-up of my transmission replacement soon Thanks dme!

Dan Martinic

Hold on--early cars had speedo data taken from the front yet their transmissions had a hole--not fully excavated--where the future sensor would go?

That's weird

dme

Wow, from a speed sensor to a transmission. Repair on these cars gets more expensive every day. Hard to believe a PO would put an old transmission in knowing the speedometer would never work. But, we find strange things every time we open up these 30+ year old cars.

Dan Martinic

I was thinking about why that non-hole would be there.. then I realized that these are Audi transmissions; the four rings stamped on them gives it away lol

Probably some Audi car used the speedo point on the trans.. but this was not fully drilled out for the 944. I wonder if you drilled it out and tapped it, could you install the pieces needed (the shaft, gear, threaded piece, sender, etc) and retro-fit the newer speedo sender? Easier and cheaper then swapping the transmission?

Kevin G should know this instantly

Tiger03447

I don't know what kind of speedo might be in your car, but he may have swapped out the speedo as well if the PO went with the earlier speedo Drive. All you need to confirm that is to look on the backside of the L front spindle. The speedo drive goes right in the back of the spindle. As far as the later model speedo drive unit goes, I don't know what kind of a "trigger" would be in the transmission to actuate the module for the later model speedo. Kevin Gross would know this off the top of his head. I would not go drilling into the case because of chips etc.getting into the gearbox section. That could lead to a catastrophic failure...and you would still be out a gearbox. Just my 2 cents..