Now that we all agree, please keep this info handy for search purposes.

Special thanks to the guys who gathered this information. You are what makes PFF such a great place.

The pilot bushing / insert is a VERY important part in the 2.5 engine. It helps locate the flywheel or the torque converter and keeps it centered on the crankshaft. THIS BUSHING IS VERY IMPORTANT do not skip the installation of it.

ADDED:
If your crank looks like the one pictured below(?), order Federal Mogul PB650 or equivalent and install it before re-assembling your flywheel/clutch/transmission.

quote Originally posted by KurtAKX: Here's what the pilot bearing does: This is a picture of an iron duke flywheel installed on the back of a crankshaft which has a FACTORY INSTALLED pilot bearing in it. The engine is in a "normal" orientation. The only thing holding the flywheel on to take this picture is the "snug" fit of the flywheel bore being piloted by the bearing. It is the only feature which keeps the flywheel centered; there are no dowel pins or shoulder bolts to do the job!!! If you don't believe me, pull out your Iron duke and do the following: 1) Get a measurement off the flywheel bore 2) Take calipers over to pilot bearing; note that bearing diameter is the same as flywheel bore diameter (duh, that's why it was put there for stick cars.)

quote Originally posted by FrugalFiero: Here are the part numbers. Part number listing from the 84-88 P Fiero 22P microfiche: It would appear the words "insert" and "pilot bushing" are one in the same. The part numbers are in line with the earlier listing I posted, except it includes 87-88. 84-87 P Engine Asm - 2.5 L4 (LR8/2.5R) Spacer, Flywheel to Crankshaft - 10005655 Insert, Cr/Shf - 10018699 88 P Engine Asm. - 2.5 L4 (LR8/2.5R) Spacer, Flywheel to Crankshaft - 10005655 Insert, Cr/Shf (W / M.T.) - 10009785 Insert, Cr/Shf (W / A.T.) - 10018699 http://www.automotix.net/au...epair_guide-782.html Crankshaft Flange Inserts on GM 2.5L (151 CID) Engines General Motors Corporation uses 3 different crankshaft inserts on their 2.5L (151 CID) engines. These steel crankshaft inserts are pressed into the tail end of the crankshaft and provide support for a pilot bushing on vehicles with manual transmissions or directly support the nose cone of the torque converter on vehicles with automatic transmissions. Use the following chart and diagrams when selecting a replacement crankshaft or steel crankshaft insert: Model Year Drive Model Part # 1984 RWD Fiero w/auto trans.10018699 1984 RWD Fiero w/manual trans. 10009785 * w/ auto = vehicle with automatic transmission w/ manual trans. = vehicle with manual transmission It is recommended to inspect all crankshafts to ensure that the proper insert is installed to match the desired application. The AERA Technical Committee January 1988 - TB 477 ##END## http://www.automotix.net/au...pair_guide-1911.html Crankshaft Pilot Bushing Update On 1979-93 GM 2.5L Engines The AERA Technical Committee offers the following information regarding an update on crankshaft pilot bushings for 1977-93 GM 2.5L engines. Previously, AERA published Technical Bulletin TB 477R. The information in this bulletin is to be used in addition to that bulletin. GM has used six unique crankshaft pilot bushing inserts for their different 2.5L engine applications. These inserts are pressed into the rear of the crankshaft and provide support for either the input shaft of a standard transmission or direct support of the torque converter hub of an automatic transmission. Use the following chart and diagrams when selecting a replacement crankshaft insert, keeping in mind GM also supplied engines to the Jeep Corporation for postal use: Model Year Drive Model Part # View 1984-86 RWD Fiero w/ automatic trans. 10018699 C 1984-86 RWD Fiero w/ manual trans. 10009785 B It is recommended to inspect all crankshafts to ensure that the proper insert is installed to match the desired application. AERA is currently aware of several aftermarket suppliers for some of the above mentioned inserts. The AERA Technical Committee

[This message has been edited by 84Bill (edited 11-19-2008).]

Jesus christ bill, how many times are you going to start another post about the same thing we are still talking about.

The PILOT BUSHING is irrelevant in the engine, the crankshaft insert is critical. If you go into a parts store and ask for a pilot bushing, you are going to get a pilot bushing, and its not going to do crap.

Let's brake it down like a fraction:

If you have THIS you are fine


if you have THIS you need a crankshaft insert

[This message has been edited by 86GT3.4DOHC (edited 11-19-2008).]

quote Originally posted by 86GT3.4DOHC: Jesus christ bill, how many times are you going to start another post about the same thing we are still talking about.

As many as it takes so that the PROPER information can be received without having to wade through garbage to get it

Please note:
Part number listing from the 84-88 P Fiero 22P microfiche: It would appear the words "insert" and "pilot bushing" are one in the same

If your crank looks like the second picture, order Federal Mogul PB650 or equivalent and install it before re-assembling your flywheel/clutch/transmission.

[/fighting]

Posting just because I have in the other 2 about the same thing!