I am getting conflicting information about the usage of a pilot bushing in the crank for the V6/L4 and 4/5 spd xaxle. Some tell me there is none (which I find hard to believe.) The parts stores list many. There are differing sizes where the L4 appears larger ID for some years. The V6 has a consistent ID. This would mean that the L4 4 spd (1984) has a larger input shaft to the xaxle, and the 5spd and V6 4 spd are consistent ID. Does anyone have the diamater of the input shaft for the 4SPD V6 or 5SPD V6 Getrag? I am looking at a 4spd that has an aprox .75" input shaft...not sure of the actual vehicle it was in.

If no pilot bushing exists...then what is so special about the xaxle design that does not require one? It appears to have a long collar to help with the throwout bearing and a very short input shaft compared to the larger rear wheel drive transmission. Does this obviate the need for an good fit pilot bearing? If there is one, are people just lucking out by not carefully selecting the correct pilot bushing? I am switching from an auto V6 to a Manual 4 spd V6 and want to do the right thing. The auto torque "pilot" shaft is larger than the 4 spd by a bit so it would leave the shaft loose (not good traditionaly) if no pilot bearing was replaced.

The Getrag at least does not use one.

The transaxles are in fact different than a longitudinal drive train. In a longitudinal transmission, the input shaft is supported by one bearing at the front of the case and one bearing only a couple of inches behind it where the output and input shafts meet. In order to be stable against the side loading of the counter shaft gear, it needs more support, which it gets from the pilot bushing in the crank shaft.

The transverse transmission input shafts have one bearing at the close end of the case and one bearing at the far end of the case. These bearings are close to 10 inches apart and all the loading from the gears occurs between them. They support the input shaft well enough that it does not rquire a pilot bushing.

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'87 Fiero GT: Low, Sleek, Fast, and Loud
'90 Pontiac 6000 SE AWD: None of the Above

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

Then why the heck do the parts stores sell pilot bushings for these cars? Cosmetic? It must provide some extra stength. Perhaps it is advisable for more extreme applications?

The Fiero 2.8 does not use or require a pilot bushing. Some of the 2.5's do.

quote Originally posted by Probecar1994: Then why the heck do the parts stores sell pilot bushings for these cars? Cosmetic? It must provide some extra stength. Perhaps it is advisable for more extreme applications?

The 2.8 also came in RWD configurations, and they may use a pilot bushing.
I've done clutch swaps in 2 different 2.8 Fieros with 5-speed Getrag transmissions. Neither had a pilot bushing.

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quote Originally posted by Probecar1994: Then why the heck do the parts stores sell pilot bushings for these cars?

Many of these guys also can't look up parts correctly for the Fiero. Some don't even know it's a GM!

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Fiero Fiesta - August 1, 2004 - Calgary, Alberta

3.4L S/C 87 GT www.fierosound.com
2002/2003 World of Wheels Winner &
Multiple IASCA Stereo Award Winner

quote Originally posted by jelly2m8: The Fiero 2.8 does not use or require a pilot bushing. Some of the 2.5's do.

none of the fiero trannys use a pilot bushing

quote Originally posted by buddycraigg: none of the fiero trannys use a pilot bushing

Your right, the transaxles don't use a pilot bushing. A pilot bushing goes into the end of the crankshaft to support the input shaft on a manual transmission / transaxle and supports the stub on the end of the torque convertor on an automatic transmission / transaxle on those vehicles so equipped with a pilot bushing, or pilot bearing.

Some 2.5L manual transaxle Fiero's do use a pilot bushing. Which ones exactly, I can't say, there is most likely different crannkshafts that were installed in some. I've seen numerous pilot bushings in 84-86 Fiero 2.5 crankshafts.