I've got a V8 mated to the original 5-speed Isuzu gearbox that has been with the vehicle it's whole life.

I don't do a lot of showing off, and I really don't drive the heck out of the car. On my way to work this morning, everything was going fine - then after pulling away from a light (just cruising - I don't race at this hour) and shifting into 2nd gear, I could hear a distinct rattling coming from behind me, and to the left (gearbox).

At first I thought it was a throw-out bearing, but realized this noise ONLY occurs when in 2nd gear. So, I avoided shifting into 2nd gear coming home tonight (easy to do with a V8 - I can start from 3rd with no worries).

I just want a diagnosis here on how difficult a rebuild I'm looking at....assuming the pinion shaft isn't blasting it's way through the innards of the gearbox. I started to think syncro gear, but I can shift easily into 2nd gear, without difficulty and grinding. It isn't until there's load on the thing that it begins to rattle. Sounds a lot like a bearing gone south in there...

The good news is I was planning on dropping the engine this winter anyway to repair some oil leaks.

I'm looking for experienced input here - could I be correct in my diagnosis, and if it's not badly damaged, should I be rebuilding this or looking for something else?

If I do have a rebuildable unit, would I be further ahead to look into beefier parts for this?

My isuzu on my 350 started ticking in second gear only.
The next time I floored it in second I tore the teeth off of second gear.
Here is some pics of the damage. https://www.fiero.nl/forum/Forum2/HTML/041470.html

I noticed later that the mating gear to the damaged gear (in the last photo) is completely stripped of teeth.

I don't want to be an alarmist but your symptoms sound very similar to mine.
Then again, I could be wrong.
You can probably nurse it by starting off in first and shifting to third.
Starting in third may eventually glaze your clutch resulting in chattering.

I would be tempted to toss it and pick up another tranny. Much cheaper likely than a rebuild.

wrap it in duct tape!!!

tstroud: I recall seeing your original post. It's not just a ticking....it's pretty loud, and seems pretty random. But anyway you slice it, something is wrong with 2nd gear. My clutch is some sort of custom racing clutch - it doesn't slip starting from 3rd, period. The engine labours a wee bit, but that's all. The car is done for the season - I really have no need to drive it now until next year, so I don't need to baby it. I just want to be prepared for what I will find when I get it in the garage. Lucky for me, this isn't my daily driver.

Did you end up rebuilding that mess, or replacing it?

FieroBuzz: Hard to find ANY 5-speeds up here for the Fiero. While it may be pricey, the idea is to repair this unit (if it's not too far gone), and to have a spare (when I eventually find one). As time goes on, these things are going to become increasingly difficult to find. If I can't find a spare, rebuilding this may be my only option.

Lambykin: I replaced mine, they aren't too hard to find here.
I presume mine had bits of gear teeth all through it, so I didn't even think about fixing it.
I think you will have more money in fixing it than replacing it.
The parts are fairly expensive but the whole thing is pretty cheap.

Someone here on the forum offered me a free one but it was too far away, like the east coast.
Maybe you ask around to see who has one.

I still have mine if you want to see more pics.

I know replacing it will probably cost a lot less, but I wouldn't mind a spare unit if this is rebuildable. Of course, I could be getting ahead of myself. If there's too much wrong with it, I will have to just junk it. I won't know until I pull everything, and that won't be for a little while.

As for asking around - I posted in the Mall - nothing yet.

I'm doing a N* swap, so I got 3 of em for 100 each with cables at my local junkyard. I would go that way instead of rebuilding.