Just a heads up. I have had differential oil leaking out of the birdfields for many years. I recently read where removing the vent valve from the front differential might help. I removed the valve and ran 1/4 fuel hose from the original vent location up to the brake master cylinder and voila, no more leaking oil. My vent valve would work, but would allow either a slight amount of vacuum or pressure depending on temp. This was enough to either pull in birdfield grease or leak out differential oil. Looks like just an open vent solves both these problems.
Ront Differential Venting and Leaking Gear Oiler (1 Viewer)
- Thread starter FJ80HI
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- differential gear leaking oil
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inkpot
SILVER Star
They VERY rarely heal themselves!
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- #4
The seals were replaced about 30 k miles ago (6 years ago), they started to leak about 15 k miles ago (3 years ago).. There is a small amount of pressure that builds up in the differential when driving due to heat and a slight vacuum when the diff cools down. This is just enough pressure or vacuum to cause the oil or grease to move through the seal. Now no leak as there is no pressure differential. No leak no problem. I should add the leak was a pint of oil about every 10,000 miles. Oil would drip on the tires after parking.
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- #6
Grease has always been in the birfields, check regularly and grease on maintenance interval. The differential oil has been dark in the past (where rear looks like gear oil), so guess was the dark oil caused by birfield grease leaking into diff oil. Now it appears oil and grease staying where they should. When I removed the vent valve, it was clear, but it would take a small amount of pressure to open, and in the past, when I checked front diff oil I would hear a his when I opened the plug. The his was air relieving the vacuum that had accumulated after the differential cool down. And there would be some diff oil dripping on the tires from when the truck was shut down and diff oil hot and under some pressure.
