How often do you change your diff fluid?
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Senior User
Joined: Jan 2006
Posts: 400
Likes: 1
From: Calgary, Alberta, Canada
How often do you change your diff fluid?
Had a driveshaft seal on the diff leaking so took it in to get it repaired and $1000 dollars later...... The yoke had to be replaced as it developed a groove in it and a new seal wouldn't fix it. I was told that, the truck has only 42000 miles on it, since it is 8 years old the oil breaks down and can cause problems in the metal. It was suggested it be changed every 2 years. I haul a 10k fiver for maybe 800 miles a year so the truck is not working hard. Any one else have a similar problem?
Senior User
Joined: Jul 2004
Posts: 262
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i like to change mine out every two years or so. diff gears and bearings during use create tiny metal particles as the two parts turn together the particles stay in the oil so thats why i like to change all my fluids around every 2 years. got 90k on my 250 and the axles and tranny are still in great shape, even after my occasional beatings i give them.
Posting Guru
Joined: Jan 2004
Posts: 2,105
Likes: 3
From: Anchorage Alaska
i change mine everytime i go 4 wheeling in water and get water past the axle shaft seal...
Ray
Ray
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Ford Truck Loyalist
Joined: Jan 2007
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From: Countryside Township
The '99 F250SD is the first 3/4 tonner I've ever owned but it's getting the same treatment I've always given my 1/2 tonners--axle and trans lubricant changes every 50,000. I've used nothing but synthetics since they became widely available. Never yet had any trouble.
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Elder User
Joined: Sep 2004
Posts: 851
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From: N. Georgia
The trransfer case is just Merco/Dexron III transmission fluid. Approx 2 quarts. MAKE SURE you can get the top fill plug out before removing the bottom drain plug. If your '03 is the same as my '02 then the front is Hypoid Gear Oil - SAE 90, the rear is SAE 75-140 Synthetic. You will also need some limited slip additive for the rear end.
Joe
Joe
Senior User
Joined: Dec 2006
Posts: 366
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From: Rhode Island
For the synthetic 75-140 needed in the rear axle look at Mobil1 or Royal Purple as they are very good oils. The front axle is not synthetic so any Castrol, Penzoil, regular Mobil are all fine. Same for the T-case, stick with a name brand ATF.
