JustGreg

Brand new here and looking forward to learning from everyones experiences...good and bad. Please bear with me with this as it's going to initially appear my reply here is in the wrong thread.

I just bought a midlife crisis 96 WS6 and with 68K miles on it. As (my) luck would have it I didn't have it long before many things that passed muster during pre purchase began failing. Such is the expected fun of buying a 20 year old vehicle eh?

Recently I was sitting at my bank idling with the AC on and the engine or something developed a left lower rear of engine knock. I had good oil pressure and great cooling going on with fans manually engaged on high while I continued to track down why they weren't functioning automatically correctly. However that isn't why I'm posting in this thread per se'.

I've researched the hell out of this car in the short time I've had it and found a few reports of a knock similar to a spun crank bearing coming from the clutch area; I believe specifically from the flywheel halves separating.

Having read this thread I'm extremely curious if the noise could be either the TO or pilot. The engine wasn't run long when the knocking started; about 10 mins and 2 miles to get it home but doesn't miss or skip and oil pressure is a warm idling 30-40. I noticed I can feel the knock right through the shifter. The shifter actually moves back and forth a smidge in time with the knock.

Now...the topic related question. Have any of you ever experienced a TO, flywheel, or pilot problem that presented with the same symptoms as a spun bearing? I'm not trying to get out of the work of dropping the tranny and oil pan to roll in new main and connecting rod bearings (don't hate...it's highly doable. I've done it many times in select spun bearing situations and the engines lived a very long life before succumbing to mileage and time. Besides, the engine will be coming out in 2017 anyway.)

I've already ordered everything new related to the clutch, new Hi output oil pump with pickup, King Hi-Perf standard bearings (yup...I'm taking a leap of faith on that by going standard), rear main seal/gaskets/keeper, gaskets, input shaft seal, output shaft seal, crankshaft oil passage cleaning brush(s), galley plugs, Redline D4 (unless someone here has a better idea), and Mobil 1 filter and full synth oil.

As for the clutch MC?..there's no way based on what I've read that I'm breaking lines. I'll move it out of the way for now and replace it all next year.

I'm very much looking forward to your replies!
*And possible criticisms for rolling in crank bearings...its gotta be making many of you cringe.

BALLSS

unless the motor was over revved or lost oil...at 68k mi it should be in VERY good condition. Yeah spinning a bearing is possible but IMHO low on the list of having what you describe as a sound/vibration source

check oil & filter for metal flakes.

I would not use a HV oil pump in a motor with stock bearing clearances. They are better suited for motors built with slightly wider bearing clearances. Just use a stock oil pump with the GM white spring

bad pilot or TO bearings do make noise. ore a grinding vs knock type of sound generally. You really can't confirm until you pull tranny & clutch to inspect

I would hold off buying a bunch of parts until you confirm the source of your noise

JustGreg

Thanks for the reply!
Yup great advice about not buying a pike of parts and I considered not having anything on hand but because I just got the car and have no idea what I'll find when I pull it all down and dig in, combined with the fact the clutch was only hooking up the top two or three inches of pedal travel, and the TO squeeled one time back in March one chilly morning...I decided replacing it all was the wise choice.
And of course it just makes sense to replace the rear main seal package while in there. And I'm not sure about which way to go with the pilot. Not crazy about high rpm roller bearings vs oil impregnated bushing but I've quasi hijacked the OP's thread enough and will do some searching here and post appropriately if what I need hasn't already been discussed.

Thanks man!! Now to get it up in the air and begin.

Sidenote...I wanted to buy four LiftStands but holy hell....they are pricey little buggers!!!! Safe and cool as hell but...ouch.