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#1 |
Registered User
![]() Join Date: Dec 2015
Location: Holland Mi.
Posts: 302
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High pitched hum
My '70 is developing an intermittent high pitch hum. It's not a squeal. It is drive line related not rpm related. Doesn't matter what gear it's in (3 speed manual) or if the clutch is in or out. Doesn't do it under acceleration. More often hear it when slowing down. Front wheel bearings are good. Iam wondering about drive shaft bearings or u joint. Any input would be appreciated.
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#2 |
Senior Member
![]() Join Date: Jun 2005
Location: Winona Lake, IN
Posts: 6,286
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Re: High pitched hum
Any vibration with the hum?
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70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Power windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear |
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#3 |
Registered User
Join Date: Sep 2014
Location: Florida
Posts: 184
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Re: High pitched hum
Check the fluid in the differential. I had a leaky cover and when the fluid got low it would make noise, most notably when at low speed or decelerating.
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Nick 1972 Chevrolet C10 Stepside |
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#4 |
Registered User
![]() Join Date: Dec 2015
Location: Holland Mi.
Posts: 302
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Re: High pitched hum
No vibration. I know the differential was full a year ago and I haven't seen any leaks, but will check that and the transmission.
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#5 |
Senior Member
![]() Join Date: Jun 2005
Location: Winona Lake, IN
Posts: 6,286
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Re: High pitched hum
Typically if the noise is only under deceleration, it signals a problem with the differential.
__________________
70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Power windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear |
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#6 |
Registered User
Join Date: Dec 2009
Location: El Dorado Ca
Posts: 3,374
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Re: High pitched hum
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#7 |
70+ ( Old Skool Club )
![]() Join Date: Nov 2003
Location: Saskatoon, Saskatchewan ,Canada
Posts: 9,118
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Re: High pitched hum
For the cost involved I'd replace the 3 u-joints and steady/carrier bearing. If the noise still persists then I go into the diff.
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1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021 |
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#8 |
Senior Member
![]() Join Date: Oct 2009
Location: Godley, TX
Posts: 17,961
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Re: High pitched hum
Could be Neil Young.
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#9 |
Registered User
Join Date: Oct 2007
Location: Spanaway
Posts: 8,451
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Re: High pitched hum
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Mike. Swamp Rat build thread : http://67-72chevytrucks.com/vboard/s...d.php?t=595019 72 3/4T 4X4 4" BDS Lift 33" BFG's |
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