I am replacing my transmission drums and the new bushings I bought are not grooved like the originals. Is this an important factor for good lubrication? My intention is to use a 5W-30 synthetic oil.
Don't know about the bushings, but be very careful with the oil. Make sure the label doesn't say "Energy Conserving" on it or you'll wind up with lots of band slippage.
You need the groove. Henry put them there for a reason.
Thanks Kevin for the heads up on the Energy Conserving oil. I'll watch for that.
Sure hate to throw a set of bushings away if they might work OK with the new thinner oils. If anyone has any first-hand experience with grooveless bushings I'd like to hear about.
I'll second what Jack had to add...
Ford 'grooving' specifications in the transmission sort of defy conventional wisdom for bronze bush oiling...both now AND even then.
I have never been able to figure out why they did what they did...but as Jack said...they must have had their reasons!
Press in those that you have, bore/ream to size, and then a lathe with a HSS ground tip tool on a drag out will shape a profile...others have apparently done so with a dremel. Just my .02
The only bushings I have seen with out Grooves are Oil-Lite. They are no good to use in a Model T anywhere.
If a vender is selling Transmission bushings with out grooves, stay away from them.
Grooving in the bushings are used as Oil Wells.
They will not run long with out Grooves.
The oil won't enter the bushing through the grooves, it enters through the ends. In my view oil grooves in transmission bearings just reduce the surface area and interfere with the hydrodynamics of a journal bearing. Henry did not groove rod bearings and they worked just fine. The mains had minimal grooving but holes for the oil to enter from the top. I wonder whether or not he grooved transmission bearings. I think your bushings will work just fine, just make sure they are not too tight.
That's my 2 cents worth.
The transmission drum bushings were grooved from Ford. Not just any groove - they were very very specific on how the groove should be cut, probably for a reason. Read George from Cherry Hill's well researched posts in this thread: http://www.mtfca.com/discus/messages/331880/355193.html?1366510858
And do use oil paddles if you ain't running magnets on the flywheel
You should have the oil grooves.
Just cut some grooves in what yo have and put them in. Use a file or hack saw and smooth the edge with file or fine sand paper. It just supplies a channel for oil to get in there new oils or not.