The Ford Barn

asbrock · 08-09-2015, 03:05 PM

Starting yesterday afternoon I have a loud hum that happens when I let off the accelerator while in any gear. I have a Borg-Warner Overdrive on my car, and what is weird is that I do not have the hum when the overdrive is engaged. I just changed transmission oil this morning, but that did nothing to help the hum go away.

I just replaced the front brake drums, front hubs, and shoes/linings this past week, but I don't think this would cause the noise?

Any tips are greatly appreciated!

BILL WILLIAMSON · 08-09-2015, 03:47 PM

NO IDEA, even the Dog cain't hear it frum HERE??
Bill W.

Bob C · 08-09-2015, 03:52 PM

I think when you are in OD you are freewheeling when you let off the gas,
when you are not in OD and let off the gas you are going against compression.
My guess is there is a problem with the OD unit or rear end.

Bob

Tom Endy · 08-09-2015, 04:10 PM

Most Borg Warner conversions use a grease seal to prevent oil inside the OD from migrating down the stub shaft and into the banjo.

Unfortunately the seal is a grease seal, not an oil seal. Most are the same part number used in the axle housings. The seal rides on an un-machined area of the stub shaft and some amount of oil makes its way into the banjo.

With a BW installation it is prudent to check the oil level in the OD and the banjo at about 400 mile intervals. If it is observed that the banjo is manufacturing oil the OD will eventually fail due to oil starvation and oil accumulating in the banjo may find its way out the rear brakes.

Tom Endy

RandyinUtah · 08-10-2015, 01:56 AM

Sponsored Links (Register now to hide all advertisements)

Can the oil also migrate from a Mitchel overdrive into the banjo like mentioned with the Borg Warner ? Last week I checked the oil in my rear end at it was a little over filled when I pulled the plug out.

08-09-2015, 03:05 PM	#1
asbrock Junior Member Join Date: Apr 2015 Location: Houston, TX Posts: 12	Transmission hum when coasting Starting yesterday afternoon I have a loud hum that happens when I let off the accelerator while in any gear. I have a Borg-Warner Overdrive on my car, and what is weird is that I do not have the hum when the overdrive is engaged. I just changed transmission oil this morning, but that did nothing to help the hum go away. I just replaced the front brake drums, front hubs, and shoes/linings this past week, but I don't think this would cause the noise? Any tips are greatly appreciated!

08-09-2015, 03:47 PM	#2
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: Transmission hum when coasting NO IDEA, even the Dog cain't hear it frum HERE?? Bill W. __________________ "THE ASSISTANT GURU OF STUFF"

08-09-2015, 03:52 PM	#3
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,753	Re: Transmission hum when coasting I think when you are in OD you are freewheeling when you let off the gas, when you are not in OD and let off the gas you are going against compression. My guess is there is a problem with the OD unit or rear end. Bob

08-09-2015, 04:10 PM	#4
Tom Endy Senior Member Join Date: May 2010 Location: Southern California Posts: 3,131	Re: Transmission hum when coasting Most Borg Warner conversions use a grease seal to prevent oil inside the OD from migrating down the stub shaft and into the banjo. Unfortunately the seal is a grease seal, not an oil seal. Most are the same part number used in the axle housings. The seal rides on an un-machined area of the stub shaft and some amount of oil makes its way into the banjo. With a BW installation it is prudent to check the oil level in the OD and the banjo at about 400 mile intervals. If it is observed that the banjo is manufacturing oil the OD will eventually fail due to oil starvation and oil accumulating in the banjo may find its way out the rear brakes. Tom Endy

08-10-2015, 01:56 AM	#5
RandyinUtah Senior Member Join Date: May 2010 Location: Ogden Utah Posts: 242	Re: Transmission hum when coasting Sponsored Links (Register now to hide all advertisements) Can the oil also migrate from a Mitchel overdrive into the banjo like mentioned with the Borg Warner ? Last week I checked the oil in my rear end at it was a little over filled when I pulled the plug out.