Never seen this before, and it was scary...

[BAC5.2]

My friend has a stage-4 WRX with a built tranny (Straight cut, snychro'd PPG gears, some of you saw/heard the dyno pull video).

He only made 270whp and 248lb-ft at 18psi on a VF22. Kind of disappointing, but good for 12's, no problem.

The funny thing, aside from the .040 spark plug gap that we found (which was causing misfires on-boost, and severely limiting power output), was that it was making some HORRENDOUS noise when in gear and driving along.

The noise was louder than the gears.

So last night, I went over to my other friends shop with Jay (guy with the WRX) and we got to work. Pulled the tranny, split it open and what do we find? VERY shreaded front diff.

If you know what a front diff SHOULD look like (teeth have a flat profile on top and are fairly wide), then you are going to shudder to hear what I am about to say.....

I cut my finger on one of the teeth on the pinion gear. The teeth on the ring and the pinion were RAZOR SHARP.

This was the first front diff that I have seen the ring and pinion go bad on. I've seen blown diffs, but never the ring and pinion turn so horrible as to have SO MUCH free play.

How did it happen? We think that when the tranny blew the first time (stock gears, totally rounded off second gear), metal was simply wedged on the ring gear, and was just ground in and jacked the pinion alll up. It's unlikely that the lash was all jacked up.

The inside of a transmission is a surprisingly calm place. It wasn't as scary as I thought it would be, and it seemed to be pretty easy. I doubt I could do it again myself, but I think I could probably get it apart, the final assembly of setting the lash and the gap that is the problem (no tools).

It was wild.

[kidatari]

Yikes! Got any pics of the resulting damage? No scars to the beautiful PPG gearset?

[BAC5.2]

No pics, didn't have the camera.

The gearset was OK, but goddamn I almost cut myself on the pinion. They were THAT sharp.

They were also all shiny, and if you've seen a stock ring and pinion, you'll know that they are everything but shiny from the factory.