Cam chest noise
Seasoned HDF Member
Joined: Oct 2015
Posts: 13,516
Likes: 34,673
From: Pine Flat Dam/South Bay Area, CA
The last time that I heard a bearing growling like the one in the first clip, it was the Timken (main) bearings that were worn out. Check the tappet screen & open the oil filter, spread the pleats, and inspect it for debris, especially metal particles. If find something, you'll know you are going in further until you find what's shedding metal.
Thread Starter
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Novice
Joined: May 2026
Posts: 16
Likes: 1
From: New Mexico
The last time that I heard a bearing growling like the one in the first clip, it was the Timken (main) bearings that were worn out. Check the tappet screen & open the oil filter, spread the pleats, and inspect it for debris, especially metal particles. If find something, you'll know you are going in further until you find what's shedding metal.
Stellar HDF Member
Joined: Aug 2020
Posts: 3,182
Likes: 2,225
From: College Station, TX
My experience is the timken bearings make a whine / whirring sound, and then get louder to a roar. Check the flywheel end end play (not run out) to see if it is excessive.
If it were mine, I'd have the engine rebuilt by a reputable HD shop that works on the older engines rather than look for a used one.
Paul
If it were mine, I'd have the engine rebuilt by a reputable HD shop that works on the older engines rather than look for a used one.
Paul
Thread Starter
|
Novice
Joined: May 2026
Posts: 16
Likes: 1
From: New Mexico
My experience is the timken bearings make a whine / whirring sound, and then get louder to a roar. Check the flywheel end end play (not run out) to see if it is excessive.
If it were mine, I'd have the engine rebuilt by a reputable HD shop that works on the older engines rather than look for a used one.
Paul
If it were mine, I'd have the engine rebuilt by a reputable HD shop that works on the older engines rather than look for a used one.
Paul
Thread Starter
|
Novice
Joined: May 2026
Posts: 16
Likes: 1
From: New Mexico
My experience is the timken bearings make a whine / whirring sound, and then get louder to a roar. Check the flywheel end end play (not run out) to see if it is excessive.
If it were mine, I'd have the engine rebuilt by a reputable HD shop that works on the older engines rather than look for a used one.
Paul
If it were mine, I'd have the engine rebuilt by a reputable HD shop that works on the older engines rather than look for a used one.
Paul
Last edited by jim@audiodogstudio.com; May 28, 2026 at 06:05 PM. Reason: clarificaton
Stellar HDF Member
Joined: Aug 2020
Posts: 3,182
Likes: 2,225
From: College Station, TX
Book calls for .001-.006. The end play is set with a spacer between the timken bearing on the sprocket shaft.
To check it you need a dial indicator fixed to the case on the end of either shaft. Push against the sprocket or pinion shaft and set the dial indicator to 0. Then press the other direction and check the movement. Search google if you want to see pictures to help get the idea. The bearings are gonig to have to be fairly bad to see much out of spec, but the noise isn't good.
Did everything in the cam check check out ok?
Paul
To check it you need a dial indicator fixed to the case on the end of either shaft. Push against the sprocket or pinion shaft and set the dial indicator to 0. Then press the other direction and check the movement. Search google if you want to see pictures to help get the idea. The bearings are gonig to have to be fairly bad to see much out of spec, but the noise isn't good.
Did everything in the cam check check out ok?
Paul
Thread Starter
|
Novice
Joined: May 2026
Posts: 16
Likes: 1
From: New Mexico
Book calls for .001-.006. The end play is set with a spacer between the timken bearing on the sprocket shaft.
To check it you need a dial indicator fixed to the case on the end of either shaft. Push against the sprocket or pinion shaft and set the dial indicator to 0. Then press the other direction and check the movement. Search google if you want to see pictures to help get the idea. The bearings are gonig to have to be fairly bad to see much out of spec, but the noise isn't good.
Did everything in the cam check check out ok?
Paul
To check it you need a dial indicator fixed to the case on the end of either shaft. Push against the sprocket or pinion shaft and set the dial indicator to 0. Then press the other direction and check the movement. Search google if you want to see pictures to help get the idea. The bearings are gonig to have to be fairly bad to see much out of spec, but the noise isn't good.
Did everything in the cam check check out ok?
Paul
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,921
Likes: 8,027
From: poway
So you bought the bike and it makes the nasty sound? The noise is definitely not the inner cam bearing. I'm not a shovel guy but the sound is like gear teeth are really loose. IIRC HD changed the tooth profile a couple times on the cams, going from gen shovel to alternator in 69/70 and in 77/78. It it possibly that they the gears are mismatched or simply the 78 up gears are matched to the pinion wrong.. You can have as much as 0.005 gear lash with a wrong combo on the later gears.
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Thread Starter
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Novice
Joined: May 2026
Posts: 16
Likes: 1
From: New Mexico
So you bought the bike and it makes the nasty sound? The noise is definitely not the inner cam bearing. I'm not a shovel guy but the sound is like gear teeth are really loose. IIRC HD changed the tooth profile a couple times on the cams, going from gen shovel to alternator in 69/70 and in 77/78. It it possibly that they the gears are mismatched or simply the 78 up gears are matched to the pinion wrong.. You can have as much as 0.005 gear lash with a wrong combo on the later gears.
Last edited by jim@audiodogstudio.com; Yesterday at 07:48 AM. Reason: clarification
