Front diff harmonics

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audiocontr
Canada
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Front diff harmonics

Post by audiocontr » Sun Oct 01, 2017 4:19 pm

Recall the sound of an unbalanced drive shaft, as it pulses while driving at speed, back and forth... The haflinger makes that sound. It always has. I'm positive its in the front.

Would too much fluid in the center shaft cause this?
1973 712m
(2) 1968 Haflingers 1 For Sale
1978 GMC Palm Beach
2001 F250 Diesel and trailer

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audiocontr
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Re: Front diff harmonics

Post by audiocontr » Sun Oct 01, 2017 5:44 pm

Is it possible that its a whistle across any of the drain holes?
1973 712m
(2) 1968 Haflingers 1 For Sale
1978 GMC Palm Beach
2001 F250 Diesel and trailer

Heinkeljb
Great Britain
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Re: Front diff harmonics

Post by Heinkeljb » Mon Oct 02, 2017 1:49 am

I think it is far more likely to be a slightly bent drive shaft due to slightly worn fulcrum pins. That will load a bearing on one side and cause a bit of noise which then because the shaft can go up and down, the loading will change.
Lurch does the same thing, so I would guess it is quite common.

John

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TechMOGogy
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Re: Front diff harmonics

Post by TechMOGogy » Mon Oct 02, 2017 8:28 am

That was my 1st guess too for a noise like that - bearing(s)
72 Pathfinder | 75 710M 2.7i | 96 350GDT Worker

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audiocontr
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Re: Front diff harmonics

Post by audiocontr » Mon Oct 02, 2017 10:13 am

Thanks gents!
1973 712m
(2) 1968 Haflingers 1 For Sale
1978 GMC Palm Beach
2001 F250 Diesel and trailer

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Jimm391730
United States of America
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Re: Front diff harmonics

Post by Jimm391730 » Tue Oct 03, 2017 9:45 pm

Check if the "pulses" happen at wheel rpm; an out of round or bent wheel will load and unload the drive train as its radius changes.
Jim M.
712W and 710M

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