Pilot Bushings for
GM Gen I-II Engines
A precisely sized pilot bushing is essential to proper manual transmission installation. It supports and aligns the transmission input shaft on center during clutch release.
GM engine crank bores feature remarkable consistency from the 1950's through the late 1990's, with a diameter of ~1-1/16". Whether Chevrolet, Buick, Olds, or Pontiac cranks, they usually take the same diameter pilot bushing. Note that Cadillac engine cranks usually don't have a pilot bushing bore, as they were all automatic transmission models post-1950's.
... to GM Transmissions
Our highest quality GM Gen I to GM Muncie / Saginaw transmissions pilot bushing.
... to T90 Transmissions
Jeep T90 transmissions have a ~5/8" pilot tip diameter.
... to T14 & T15 Transmissions
Two pilot sizes are used on the T14 transmission early (1967-1971) at ~19/32" and late (1972-1975) at ~3/4". All T15 transmissions used the ~3/4" pilot.
... to Jeep T98 (M715) Transmissions
The Jeep T98 as found in the M715 and some FSJ trucks has a ~5/8" pilot tip. Because of the numerous styles of T98 and T18 input shafts available in Jeeps through the years, it's important for the installer to verify their configuration for compatability.
... to Jeep T18 Transmissions
This pilot bushing is for 1972-1975 Jeep T18 transmissions in some applications feature a ~3/4" pilot tip. 1976-1979 Jeep T18's as found in CJ's feature a ~17mm pilot tip.
... to Jeep T150 Transmissions
1976-1979 Jeep T150's as found in CJ's feature a ~17mm pilot tip.
... to T176 Transmissions
T176 transmissions make good conversion candidates for GM power. They feature a ~15mm pilot.
... to Jeep AX15 Transmission
Two pilot tip sizes are used on the AX15 transmission input shaft: 1988-1991 AX15's had a ~19/32" diameter and ~1992+ at ~3/4" diameter. However, check yours before ordering. All NV3550's feature a ~3/4" pilot tip.
... to Jeep NV3550 Transmissions
NV3550 transmissions make good conversion candidates for GM power. They all feature a ~3/4" pilot.
... to Jeep NSG370 Transmissions
All Jeep NSG370's feature a ~3/4" pilot tip.
Is there a pilot bushing you want but don't see? Let us know. We might be able to make one to match your needs.
Installation Requirements
Removal of the old bushing and cleaning the crank bore is required prior to installation. There are a number of official and unofficial methods out there to remove the old bushing/bearing. Hydraulic removal using inserted grease behind
the bushing (or wet paper towel, etc. and a precisely sized rod is a classic. Our preferred method is a slide puller available from your local parts store as a rental tool if you donâÂÂt own one.
A proper drift tool or driver is recommended for installation. Do not coat oiled bronze in grease, as this plugs its pores and will not lubricate properly afterwards. Installation as the bushing comes is acceptable, though soaking it for a day or longer in clean engine oil prior to installation is preferred. Freezing the bushing and lightly warming the crank can ease the installation. Pilot bushing and transmission input and main shaft damage are inevitable if the bellhousing and transmission are not centered concentric and parallel to the engine face. We recommend the use of a dial indicator to verify that your bellhousing and engine are centered on the bellhousing bore. See The Novak Guide to Clutches, Linkages and Bellhousings for directions on this method.