Evo 2 Tranny, Center Diff Toast?

[Greeno]

So, my 98 Tsi AWD (with a 6bolt) has an Evo 2 Transmission in it, after doing some maintenance (TB) and swapping the cyclone manifold off, I changed engine oil, tranny oil, diff oil, (pennzoil syncromesh,) and fuel filter. I then took it for a drive home. Between the shop where I can work on it and the place I live, I took a route that involved 10 miles of gravel, and about 40 miles of pavement. About 5 miles from home, she emitted a loud, nasty grinding and I quickly pulled to the side of the road to take a look. It was dark and rainy, and all I could see was that the driveshaft wasn't dragging on the pavement. I tried driving real slow in first gear, it made a much quieter grind twice, then nothing. I limped it the last 5 miles home, thinking I had toasted the center diff for sure.

This morning, I drove around a bit and it seemed ok, was going to head for the shop again, and a similar grinding started only 5 miles out of town. Stopped, tried moving the car in R, and 1st, no grind at low speed, returned home.

Do you people think that the Evo 2 tranny was put in without changing the necessary components to put it to a 3.545 ratio, and its running 3.909 front and 3.545 rear?

There are a few reasons Im not 'certain' this is the case, it was driven from my home, to my shop, on a route that consisted of 10 miles of pavement and 20 miles of gravel, and didn't exhibit any similar symptoms... Shouldn't the center diff have locked up on that drive? Even if it was never driven more than a block after the hack shop did the tranny swap?

How can I determine if there are different drive ratios to the front and rear wheels? If I put it on stands, put it in gear and turn the motor by hand, will I be able to count different revolutions on the front and rear wheels? Or will the center diff make up the difference ( now that I type this I realize it won't unless the fluid was warm enough to lock the plates together, right?)

So, onto stands I go, to count wheel revolutions, correct?

Thanks for reading my essay, and helping out

Edit: is it possible the front ring gear was swapped to a 58 tooth ring gear (90-96) and then had the original transfer case used? this would cause a much smaller difference in the drive ratios, if I'm understanding everything correctly

looks like the front ring and pinion wasn't changed... I would have thought the VC would have locked up much sooner than 30 miles of highway, haven't got the transmission out yet but the t-case oil is FULL of metal...

 

[Greeno]

No one with some ideas here? I'm now hearing that in addition to the tranny and t-case needing to be matched, that the rear differentials were different in 97-98? can anyone confirm?