So, I get everything all apart, dash, cluster, etc and pull the odometer and wouldn't you know it, the little gear that usually breaks was intact - it was the big gear that had bit the dust. Of course I hadn't ordered that one..

 

D'OH I can sympathise with your frustrations. It was my big cog that had broken too. I ended up replacing both, seeing as I had already ordered the small one.

 

on a better note, went to a junkyard today and found a cluster already out and was able to get the gear I needed for $0.50! Even better was I got a "R" front bumper in great shape for $60 and I got the "R" stainless sill plates for $4 each! Not a bad day!

 

Where are you located? you could also get a 98 s/v/c70 cluster and plug and play in your 850, as long as it's 96-97.

 

If you have all the pieces, I've had pretty good luck in the past just gluing it back together with some super-glue, drilling the hole very slightly larger, and gluing it back on to the shaft.

i grew up (arguably...) with V-dubs, which have the same problems. This is how the problem was described to me --

At the factory, they press a plastic gear onto a metal shaft, and that's it. Over time, the plastic degrades, and the internal pressure from the shaft causes it to split.

At that point, one of two things happens. First, the gear breaks in two, and falls off the shaft. Or, the gear simply flexes open at the split, and the drive gear is therefore unable to turn it.

Like I said, if you drill out the hole just a little bit, you relieve the pressure on the plastic when you put it back on the shaft. Obviously that lack of pressure means the shaft won't turn, which is why you glue the gear to the shaft.

Worked for me a couple times

 

all the pieces were crunchy. Like I said, I got a good gear from a yard for $0.50. The replacement gear online sells for over $20. I can pull the cluster out pretty quick now that I have done it once.