Rear Differential maintenance - 97 5.4L XLT Expedition
riproaringca
11-03-2007, 10:22 PM
Hi all,
I have a 1997 5.4L 4x4 XLT Expedition with a limited-slip (Trak-Lock) Rear Differential.
In case it helps someone else, I thought I would share my experience in changing the gear oil and gasket on my rear differential. It's not that hard to do, but from what I've read/seen it looks like there are a few different formats of rear axles out there. Here's how mine went:
First of all, I was told by a couple of auto parts suppliers that a gasket usually isn't needed - just a good application of suitable RTV gasket silicone. Sure enough, when I removed the rear differential's cover there wasn't a gasket in place - just (black) silicone.
During my search for an axle code to determine what kind I had, I discovered that only 75W140 SYNTHETIC grade gear oil was to be used. (This wasn't mentioned in the Ford-issued owner's manual or the Haynes maintenance manual I have.) There are a couple of metal tags bolted to the differential cover. The specs are stamped into these tages. This is where I found the oil specification.
Removal of the cover was easy. I paid careful attention to clean the area around and above the casing first so that grit and debris didn't fall into the open area containing the gears.
My cover was held on by twelve, 1/2" bolts. Once these were removed I only had to give the cover a little tap to work it loose from the old sealant. (Make sure you have an oil drain pan ready underneath!) There's about 2.5 litres (5 pints) of fluid in there. Again, I was careful not to let the cover rap against the surrounding metal, avoiding any foreign garb from falling into the works.
My rear diff had been showing signs of a slow leak. The cover was wet with fluid and there was that telltale shudder upon acceleration, which has been described in other threads in this forum.
Even the cover itself had corroded after 10 years of Canadian elements. Lots of surface flaking which I cleaned off to make sure the integrity of the cover was intact. The inside of the cover was solid, too - thankfully.
Once I had removed the rusted flakes, I washed the whole item with paint thinner, allowing it to dry completely afterward.
The mounting surface on the axle was still in decent shape, so I cleaned that with thinner as well. (Before reinstalling, I made sure to wipe it down with a dry cloth so that the new sealant would hold.)
To reinstall, I used a high-heat flexible RTV silicone sealant. A good bead of this was put around the mounting surface on the axle. I prepared the bolts with a bead of sealant around their underside collars as well. Each were hand-tightened to allow the silicone to seat, then after about 30 mins they were tightened down.
Refilling the rear diff was different than how my manual had described it: There wasn't a refill plug! Instead, there's a sensor on the top of the axle housing facing the front of the vehicle, which is held in place by another 1/2" bolt. (Remove the bolt and carefully pry the sensor up and out of its seat with a flat screwdriver.) Removing the sensor gives you the decent-sized hole to refill the casing using a small funnel. Again - be sure to clean the area first so that grit doesn't fall in while removing that sensor!
I did add an additive to the gear oil that is required for limited-slip differentials. Without the heads-up from the auto parts staff I wouldn't have known to do so - it's not in the manuals!
So far so good - no leaks! And, the shudder seems to have been remedied, too!
Hope this helps!
I have a 1997 5.4L 4x4 XLT Expedition with a limited-slip (Trak-Lock) Rear Differential.
In case it helps someone else, I thought I would share my experience in changing the gear oil and gasket on my rear differential. It's not that hard to do, but from what I've read/seen it looks like there are a few different formats of rear axles out there. Here's how mine went:
First of all, I was told by a couple of auto parts suppliers that a gasket usually isn't needed - just a good application of suitable RTV gasket silicone. Sure enough, when I removed the rear differential's cover there wasn't a gasket in place - just (black) silicone.
During my search for an axle code to determine what kind I had, I discovered that only 75W140 SYNTHETIC grade gear oil was to be used. (This wasn't mentioned in the Ford-issued owner's manual or the Haynes maintenance manual I have.) There are a couple of metal tags bolted to the differential cover. The specs are stamped into these tages. This is where I found the oil specification.
Removal of the cover was easy. I paid careful attention to clean the area around and above the casing first so that grit and debris didn't fall into the open area containing the gears.
My cover was held on by twelve, 1/2" bolts. Once these were removed I only had to give the cover a little tap to work it loose from the old sealant. (Make sure you have an oil drain pan ready underneath!) There's about 2.5 litres (5 pints) of fluid in there. Again, I was careful not to let the cover rap against the surrounding metal, avoiding any foreign garb from falling into the works.
My rear diff had been showing signs of a slow leak. The cover was wet with fluid and there was that telltale shudder upon acceleration, which has been described in other threads in this forum.
Even the cover itself had corroded after 10 years of Canadian elements. Lots of surface flaking which I cleaned off to make sure the integrity of the cover was intact. The inside of the cover was solid, too - thankfully.
Once I had removed the rusted flakes, I washed the whole item with paint thinner, allowing it to dry completely afterward.
The mounting surface on the axle was still in decent shape, so I cleaned that with thinner as well. (Before reinstalling, I made sure to wipe it down with a dry cloth so that the new sealant would hold.)
To reinstall, I used a high-heat flexible RTV silicone sealant. A good bead of this was put around the mounting surface on the axle. I prepared the bolts with a bead of sealant around their underside collars as well. Each were hand-tightened to allow the silicone to seat, then after about 30 mins they were tightened down.
Refilling the rear diff was different than how my manual had described it: There wasn't a refill plug! Instead, there's a sensor on the top of the axle housing facing the front of the vehicle, which is held in place by another 1/2" bolt. (Remove the bolt and carefully pry the sensor up and out of its seat with a flat screwdriver.) Removing the sensor gives you the decent-sized hole to refill the casing using a small funnel. Again - be sure to clean the area first so that grit doesn't fall in while removing that sensor!
I did add an additive to the gear oil that is required for limited-slip differentials. Without the heads-up from the auto parts staff I wouldn't have known to do so - it's not in the manuals!
So far so good - no leaks! And, the shudder seems to have been remedied, too!
Hope this helps!
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