Synchros stuck in Geo Metro 5- speed manual trans

[buggywhip]

I have a 1991 Geo Metro that was in storage for 7 years, with 75w90 in the 5-speed manual trans, which was fine before that, but now I can't downshift to 1st or 2nd without stopping or double-clutching, since the 1st and 2nd gear synchros aren't doing their job. Downshifts to 3rd and 4th work fine.

I envision the car sitting for 7 years and the the oil forming varnish or sludge and binding things up. Is that possible? If so, is it realistic to suppose that a solvent or additive could break this up, and if so, what would it be?

I was told by a mechanic they could be freed up by removing pan and moving them around by hand, but am hoping to avoid this, also wondering if anyone has tried this.

Also, have a used trans but know nothing of its history. Is there a way to check its functions before I go to the trouble of installing it?

[dcb]

I've never heard of synchros freezing up, but it doesn't mean it isn't possible. You should be able to apply plenty of torque to them by holding the shifter so it is just barely engaged and bumping the car back and forth in the driveway, might chip a tooth too, but there's no "pan" to remove per se.

Does it grind when you go into first/second?

I think 1st and 2nd are on the same shifter fork, so something might have gotten bent. But first check your shifter bushings for slop, that's an easy fix and can create all manner of shifting problems. And certainly research TeamSwift.net for more metro specifics.

[buggywhip]

"Does it grind when you go into first/second?"

No, the shifter just won't go to 1st or 2nd positions unless I double-clutch or stop.