Back to Rumble Seats advice:
PILOT BEARINGS: These provide needed support for the front of the
transmission’s main drive gear. It primarily operates only during engagement and dis-engagement of the clutch. When the pilot bearing becomes worn, it permits the main drive gear to jump up and down in the flywheel, the throwout bearing,and the clutch disc. Not a good thing. This is certain to promote clutch chatter and erratic clutch operation. (Ever wonder what the thrust bearing on the engine crankshaft is subjected to during clutch chatter? Scary!) There are two types of pilots used in the flathead.... bushing and bearing.
Bushing type: These are usually made from “Oilite” (a trade name for porous bronze that is impregnated with oil) and are simply called bronze bushings. Oilite wears fairly fast due to it’s softness and porosity. Ford specifies a maximum wear of 0.006". It’s not uncommon to find some worn as much as 0.080"-0.100"! Many have been beat on so long they’ve become egg shaped. When installing a bronze bushing, lube it with a very thin film of high-temp grease on the inside of it’s bore. Rule of thumb I use is to replace the bushing whenever I am looking at one.
Bearing type: These replace the bronze bushings. Because bearings are made of quality hardened steel they last a long time. Most are a sealed type bearing and come with a little cheap low-temp grease. Generally this thin grease is slung out in to the clutch area the first time it’s used. A cure I use is to remove the soft neoprene type seal on one side of the bearing using a sharp pick tool. I’m careful to not damage the seal since I’ll re-use it. Clean the bearing with solvent and dry it with air and/or heat. I don’t spin it with air since it’ll quickly ruin the bearings and races due to heat generation. I work some (don’t pack it since it’ll just sling it off) high-temp thick grease into the bearing (I use Lubriplate #70 which is intended for wheel bearings, but it’s no longer available.). Reinstall the seal and install the bearing. I do this to every new pilot bearing I put in (OHV and FH). Most bearings treated this way last nearly 100,000 miles. Otherwise the cheap grease they come with is gone quickly and the bearing is soon galled and junk. I prefer bearings over bushings since I’m lazy and don’t want to work on things much anymore.
