944S2IFISH2

Looking for help about the speedo sensor on a '90 S2 5spd...

How does the sensor work? It looks like there is a geared shaft that picks up the revs from a shaft inside the tranny and in turn spins a hall effect (or something) in the plastic sensor case that screws onto the outside of the transaxle case...

Questions:

1) Is there a geared shaft that makes mechanical contact to the driveline?

2) If "1" is yes, What does it make contact with? (What spins it?)

3) Is the shaft part of the speedometer sensor? Or a seperate piece?

4) How do you remove the shaft/sensor?

Thanks in advance!

James86-951

I just happened to see the speed sensor when removing the left output shaft to change a seal. The sensor spins off of the output shaft. (I believe) It appears as though there is only a bolt holding it in. It just slides out.

I have not looked at the manual and I am unsure if the '86 5 spd is similar to yours.

Hopefully that's not too much "non information."

Oddjob

The geared shaft coming out of the sensor is driven by a platic gear that is on the differential.

The shaft is a separate piece from the sender assembly and it will pull out.

Unplug the wire connector, and use a wrench on the hex flats at the base of the sender.

I removed the sender and shaft with the trans out of the car and there is no issue with removing it. My only concern with the trans in the car would be to allow the differential some movement so the platic teeth on the shaft will clear the gear teeth on the differential as you pull it out. Youll have to have the rear of the car in the air (wheels off the ground) to get at the sender anyway, just leave it out of gear. You may need to slowly turn a rear wheel as you pull the shaft out. Both mating parts are plastic, so be careful and dont force it.

944S2IFISH2

Thanks guys, great info!
More Q's...

1) How does the plastic gear mount to the diff?

2) Can you get access to remove it by "just" pulling the left (U.S. driver's side) output shaft and side coverplate?

3) Does anyone have a part number for the shaft and gears (Assuming they are trashed).

4) Is this one of those common failure parts (Like the rubber clutch hub, etc.)?

Thanks again in advance!

Oddjob

The gear slips over the end (stub axle collar) of the diff outside of the bearing.

No, cant get at it w/o pulling the diff, which requires dropping the trans and pulling the gear carrier assy out.

Cant help on the part numbers

Dont know if its a common failure, kind of doubt it, though; never heard of it happening before.

Why do you think yours is bad?

944S2IFISH2

Oddjob - My driveline started to make this odd "jingling" sound, not gear whine or anything like that, just this wierd jingling at certain revs and loads. It was particularly bad in reverse, under load. It sounds almost like a tinkleing ratchet sound. The box shifts fine in all gears so the synchros and gears seem like they'd be ok. The clutch was replaced at about 67K (About 70K on it now) with a sachs sport with new pp, T.O, pilot, etc.

Last night I took it for a little lap around the neighborhood to try to get more "data" and I noticed the speedo was starting to bounce and hang a little and it dawned on me that the two problems might be related...

I guess I'm reaching, but it seems like it might be...

special tool

What the heck are you guys talking about?????????

1. remove allen bolt holding driver side output
2. pull out output
3. remove oil seal
4. remove plastic drive gear (with fingers)

Taking out the driven gear is so easy, my monkey can do it

Luke

you let your monkey do your wreching Jim?

No wonder your car looks the way it does...


hehe... 'monkey wrench'

Oddjob

Oops.

As I said, I had my trans out when working/removing the sender. I didnt think about it fitting through the output shaft opening with the shaft grease seal removed.

Glad someone caught it, and I didnt send you on a wild goose chase.

944S2IFISH2

specialtool - Thanks for the "easy way" info! Does my previous description sound at all like this could be the cause of my noise? My fear is that I'm going to get it open and find that the speedo gear failed because a chunk of hardened steel ring (or pinion) gear was floating around inside

I've got the shop manuals, parts & tech ref catalog, and haynes, but I still can find a pic of what the speedo gear looks like or a part number for it...

Can anybody post a PET picture of it or the part numbers of the speedo gear and the shaft assembly?

Thanks again!

944S2IFISH2

Bump... (for the morning crowd)

Still looking for a pic and part numbers for this thing!