Lost the VSS and SpeedO This morning

[Tedybear]

Ok...Not the best start to my day. I need some options as I'll be doing a physical inspection on Saturday

Here's what happened:

Left for work this morning, happy the ol' girl started up. (-10 this morning) My speedometer has always had the usual little 'hop/bump' thing going on forever. This morning I could hear it a bit louder, almost like a bird chip sound. So running late as always...I continued on to the interstate. I set the cruse at 55 (It was a bit icy, and I didn't want to press my luck at 70).

(I know...Kool Story so far <G>)

So while getting up to speed I can feel the truck doing it's normal upshifts...TCC kicks in....Overdrive kicks in. RPM drops from 3200 RPM down to 2500RPM... Just as usual.

Then... (building suspense here...work with me...) The truck kicks out of cruse....Same time the RPM spikes up to 3400 RPM...And the Speedometer flat lines to zero.

Now I've been expecting the cable to break for a long time due to the rubbing it's been doing and the hippityhopp the needle always does. I do not think the cable itself snapped. If the cable snapped? The cruse would still have worked--the transmission would have remained in overdrive, etc... Because the speedo cable enters the VSS, and the VSS has the driven gear.

Cable snaps off behind the VSS? The VSS should still be able to send the speed to the ECM. To lose everything? Makes me think the gear gave up.


I need to know if my theory is sound. I might be able to pick up a VSS from the local scrapper. (He's expensive) And if I'm lucky? It might have a working stock gear attached to it.

If I'm not lucky? I know where to find the VSS. But I'm stuck for the gear? I can't seem to find the thing via my usual sources.

If the worse case? And the drive gear on the output shaft busted? I'll need a lot of help--as this uses the "Dummy Transfer Case" and I've never had it apart--nor do I know how to tear it down. As far as I know? It's just a connecting shaft with the VSS sensor attached to it.

Any ideas? I really can't drive it on the main drags due to not having the TCC and overdrive functional. I can of course do the bypass with a set of switches and bypass the computer control--but a working speedo would be nice.

Thanks!

S-

 

[Tedybear]

humm...slow response time. Must be no one's had this happen before?

**shurg**

I talked with the local dealership. They have listed two different gears for my truck. Both are still available at the warehouse in CT. (2 to 5 days to ship) Cost isn't bad.

The parts guy stated that the gear on the output shaft normally doesn't fail. It's usually the speedometer cable end gear that gives out, or the retaining "Clip" fails and gives up. Anyone have any ideas on this? I'm using a vacation day tomorrow to hopefully get into this and try to figure it out. I might change out the dragging speedo cable at the same time. (auto zone has the 71" cable listed for my application in stock for cheap)

I'm not knowing much about the clip that holds the gear onto the sensor/cable. I just hope the gear on the output shaft isn't broken. It's a dummy transfer case, but that is the last thing I want to tear into.

Now in the event the gear on that shaft is roached. (the case is empty...so if anything broke? it fell into an empty hole and I don't care to worry about it)

Is it possible to rig up a switch (and how so?) To activate O/D manually? I found the tech notes on doing it for the TCC. How about the O/D? Same type operation? If it happens to be I need to drop the transfer case? I can't do that until spring when it gets a lot warmer out. But I need to drive the truck--even without a working speedometer. Just need a way to turn on/off the TCC and the O/D.

S-