kartiste

I'm replacing the flywheel on my 99 SE-L (M/T) with a new one from the factory. The new one is p/n 12310-2Y91A, which the Nissan computer says is the correct replacement for my VIN number (same answer from two dealers). However, when it came, I had three suprprises. First, the new one is different from the old one, in that there is no cast steel material from the ID of the machined face inward. Second, the new attachment bolts I had to order with it are shorter than the old ones. Third, it came with a loose part, a stamped steel plate with 8-holes, matching the bolt-on pattern. The thickness of this plate is less than the corresponding thickness of the 8-hole "flywheel reinforcement" piece that came off the car, to the tune of ALMOST the difference in bolt length, but off by .030". I mention this not because there is an issue with the bolt length vs. hole depth - there isn't - but because it implies that I'm supposed to substitute the stamped plate for the "flywheel reinforcement" piece that came off the car.

Here is the real issue: The original "flywheel reinforcement" is a larger diameter precision machined, chrome-plated piece whose ID centers to the crank nose and whose OD then serves to center the (old) flywheel. This new stamped piece fits over the crank nose, but not as tightly, and in any case its OD is too small to mate with a flywheel land anywhere, so it cannot serve a centering function. It seems to me that this new flywheel design has to rely on the bolts alone for centering, and the holes in the flywheel are not snug fits on the bolts. I'm worried that the flywheel will have an installation eccentricity if I simply bolt it on as-is. This obviously can limit RPM and cause vibration. And there would be almost no stiffening of the hub area of the flywheel, meaning possibly chatter on clutch engagement.

The service managers at the dealers are of no help. Is there anybody on this forum who has been down this road before?

Kartiste

"Carry On, & Dread Nought"

kartiste

bump

Vlasic

iTrader: (13)

Posting some pictures would help, but it sounds like you ordered some auto transmission parts. AT flywheel bolts are shorter than MT bolts. The steel plate sounds like the an auto flywheel that a TC bolts up to. Not sure, but like I said, pictures will really help.

kartiste

No, they're not AT parts (which would have been obvious by the lack of a clutch face). I went over it in detail with the dealer - they're the current replacement items. Anyway, I finally had no choice but to install them, regardless of their engineering merits. As for possible eccentricity, it didn't seem to have any lateral slop after I put all 8 screws in the holes, before torquing them down. I'm not done with reassembly yet - wish me luck it will start, and it won't vibrate at high RPM or judder when the clutch engages!

Nealoc187

iTrader: (23)

does the new flywheel fit snugly onto the crank in the same manner that the old one did? i've never heard of this issue. I've never replaced a stock flywheel with a new stock flywheel but i have replaced one with a Fidanza lightweight flywheel and the fidanza had no centering ring (the stock one won't work with the fidanza design).

kartiste

Not as snugly as did that bowl-shaped piece - maybe a thou or two clearance.

Kartiste