rod bearings, failure

[poorbiker]

Well about 2000 miles on fl knuckle, everything going great. Went for short ride and heard bad sound, never lost oil pressure. Got home opened oil filter, lots of metal. Tore engine completely down to find rod bearings completely gone. Wrist pins, pistons, rings, cyl, case bearings, top end, all fine, no signs of oil loss or scoring or anything.
Truett and osborne wheels and rods. Oil loss is all I can figure. Am at a loss to think other wise though I know sometimes **** just fails. Wheels out and apart, going to send back to Truett/ Osborne.
Cyl walls look fine, going to do lite hone job and new rings, any thoughts on ring manufactures, Hastings, KB, S&S, Weisco, cast or moly, had moly installed. If Im going to hone cyl should I just think about 10 over, they are stock bore now, my pistons look fine, very lite scoring on thrust sides of walls, feels more or less like a good hone cross hatch would feel. Feelin a little shitty bout the whole thing..........

[sirhrmechanic]

Sorry to hear that...

Post some pictures if you can. As much for our interest.

Yes, sometimes it's just 'time' for things to come apart. The newest Knucklehead is now 67 years old. I expect that at that age, I will have some things failing (not to mention a few leaks.)

If your pistons still measure out and your bores have no taper/ovality, you can probably re-use your pistons and fit new rings... do a good glaze-break on the bores. You don't want to hone .010 over and use your stock pistons, but you know that. If you can remove the damage with .005" over pistons... go that route. The more you leave behind the better. But I don't know if .005" over pistons are available. As for pistons/rings... rings will come w. your new pistons. Or should. And if you are going to put new rings in old pistons, measure the ring-to-land clearance to make sure they are not going to fret up and down. If the lands are worn out, scrap the pistons. It's not worth turning over-size ring grooves and getting thicker rings. (we have had to do this, but only on a few cars/piston sets that are unobtanium -- it is an awful job and fraught with peril.)

Hope this helps. Sorry to hear about the failure... and, again, please share some pix.

Sirhr

[Jerry Wieland]

Well about 2000 miles on fl knuckle, everything going great. Went for short ride and heard bad sound, never lost oil pressure. Got home opened oil filter, lots of metal. Tore engine completely down to find rod bearings completely gone. Wrist pins, pistons, rings, cyl, case bearings, top end, all fine, no signs of oil loss or scoring or anything.
Truett and osborne wheels and rods. Oil loss is all I can figure. Am at a loss to think other wise though I know sometimes **** just fails. Wheels out and apart, going to send back to Truett/ Osborne.
Cyl walls look fine, going to do lite hone job and new rings, any thoughts on ring manufactures, Hastings, KB, S&S, Weisco, cast or moly, had moly installed. If Im going to hone cyl should I just think about 10 over, they are stock bore now, my pistons look fine, very lite scoring on thrust sides of walls, feels more or less like a good hone cross hatch would feel. Feelin a little shitty bout the whole thing..........

I would doubt oil loss unless the rods never got any oil from the beginning. Rod bearings do not need much oil and splash worked good on a lot of engines.

Jerry

[poorbiker]

Thnx for the replies,
Jerry, thats what I would think, if you know what they look like its easy to see that it would take alot to destroy one, they only push and pull without a ton of resistance at that. Ive pulled out old wheel,s like we all have, with who knows how many miles, to find the rod bearings surprisingly in good shape. Truett/Osborn assy wheels with of coarse all shafts, Jims, and their H-Beam rods and wheels, not sure where they get their bearings from. Sometimes things fail, maybe from setup tolerances were to close. I will try and post some pics......

[Rubone]

Check the oil passages. Crankpin hole, flywheel hole, pinion shaft hole, bushing in cam cover, etc. Something wasn't right.

[poorbiker]

will do, checked when I rebuilt but wont hurt to check again, its tough now cause there is so much fine metal.

[poorbiker]

If I did it right here are a couple pics,,,,,

[poorbiker]

Checked all oil passages, gear shaft, wheels, crank pin, gear cover, all open and clear. Took air hose and from gear shaft blew out bunch of oil through rod bearings or whats left. Left pump on when I seperated cases, turn case gear and oil spews out, though I can hear metal in it also, outside of the rod bearings the breather hole took a beating trying to pass through all the debri.
I guess I might be leaning toward it being as simple as parts failure, not due to anything in particular. I have a hard time believing the pump would not pump sometimes and then work again, my oil light which works, never even flickered,,,,,,,,,

[Steve Slocombe]

Harley Shop Dope 147 of 4 Nov 1936 advises us to use improved con rod bearing cages with a groove machined around the side, as this is an improved and strengthened retainer developed especially for lower rod bearings. They must be talking about 301-15 cage used on the 1915-36 JD/VL crank bearings, but maybe the same applies on the knuck, or perhaps some repro cages are not as strong as originals.

[poorbiker]

Sent wheels back to Truett&Osborn today. Didnt get a chance to take them apart, CJ wanted to do the disassembly.

I got around to taking apart the oil pump today to clean out any debris from inside, when I took off the cover plug for the pressure regulating ball, spring and split screw I noticed right off the screw didnt look far enough down, took my depth gauge and checked, it was only a bit more than 1/4". I know beyond a doubt that I set it at 3/8". I`m not sure what the pressure actually was cause I`m running pressure switch and light.

Any thoughts on why or how screw might have backed out, it feels really loose in threads which I dont remember being the case.

Any opinions on whether the setting was just to low and engine was starving for oil, I know on a good pump the 3/8" setting is supposed to give you around 30 psi, if I remember right.

[harleytoprock]

Since you didn't pull the wheels apart , what makes you think the bearings are bad? Too much up and down play? The big end of the rods look blue. Is that from the mfg process or over heating? The roller bearing lower ends, as someone mentioned don't need much oil. Perhaps there was incefficient clerance between the flywheels and the bearing cages.If the cages were pinched by the flywheels, things won't spin to good, resulting in failure.

[harleytoprock]

Also, be sure to give the oil tank and lines a good clean out.

[poorbiker]

The discoloration I`m sure is from heat, and the rods just rattle, yes up, down, sideways, rollers gone. I know what they should feel like, tolerances and such, there simply are no bearings left, there is as much as 1/8" or more movement in all directions....

I have disassembled many wheel sets and even built a few though I no longer have a truing stand, sold it a few yrs ago during divorce.

Again these are torque monster fly wheels from Truett & Osborn, they came assembled. I dont know what they use for their bearings and cages but their reputation is very good, used several of their wheel sets over the last 10 yrs with no issues...

Cleaned everything oil would or could pass through.

[poorbiker]

I just read on Truetts web site that the cages are allum. but not who makes them.

I found pieces of sheared off rollers in cases, like you took a standard roller and managed to cut an end off a 1/32" thick, several of these. Never seen that before....

[poorbiker]

Update on wheels,

Got them back from Truett and Osborn, no charge. Paul said that they had received a bad lot of cages and unfortunately had installed them on several wheel assy. They took responsibility even though they didnt make cages and believed them to be american made. They were very apologetic, crap happens, you make enough stuff something is going to go wrong.
Cylinders had a little scoring from rod failure, less than 5th. Had them bored to 5 over and bought a new set of KB pistons. These have an offset in the wrist pin to the thrust sides of cylinders, supposed to make for quieter operation, so far so good, was a bit unsure of this but talked a dude over at United who makes these pistons, he assured me they would be a great addition to my knuckle, we'll see.
Sounds really good but still breaking it in.