What is the recommended mileage/time interval for changing the rear differential lube on an '09 Crown Victoria Police Interceptor. The car has 63k miles currently. I remember on our old '96 Mercury Grand Marquis the recommended interval was every 100k miles.
Rear diff lube change interval on Crown Vic
- Thread starter synthetic_crazy
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100K if I remember properly!
I know my 2014 Mustang GT that I just bought, the manual says the rear end fluid is good for life unless the rearend gets submerged in water. It takes 75W-140 synthetic fluid. I think your Crown Vic has the same 8.8 rearend.
Wayne
Wayne
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My 2010 FX4 OM also states lifetime fill (it had 75W-140 MC Synthetic in it). I changed it at 13,300 miles and again at 69,600. There was nearly 3x as much iron at 13,300 than there was at 69,600. I would change it, but that is just me. Here is the UOA for both if you are interested.
Ford 9.75 ELD UOA
Ford 9.75 ELD UOA
Thanks for the info guys!
Actually, it's 150K miles. Requires 75w-140, Ford spec. WSL-M2C192-A
Originally Posted By: GSCJR
Actually, it's 150K miles. Requires 75w-140, Ford spec. WSL-M2C192-A
X2. The interval for the 7.5 and 8.8 is 150K miles.
If on the factory fill though, there will be a lot of gray junk from break in way before that. I changed the fluid on both of my Rangers before 60K miles and it looked nasty. After that though, you should be able to go a long time on any synthetic. The factory fill will be fine too, and it never gets touched on most vehicles, but I just don't like gray diff fluid.
Actually, it's 150K miles. Requires 75w-140, Ford spec. WSL-M2C192-A
X2. The interval for the 7.5 and 8.8 is 150K miles.
If on the factory fill though, there will be a lot of gray junk from break in way before that. I changed the fluid on both of my Rangers before 60K miles and it looked nasty. After that though, you should be able to go a long time on any synthetic. The factory fill will be fine too, and it never gets touched on most vehicles, but I just don't like gray diff fluid.
On my mom's 00 Grand Marquis and both my 95 and 14 Mustang GTs there is no interval, only to change when submerged. That being said the '14 will be getting a fluid change with the first OCI at 2500 miles. I have seen too many differentials wtih metal floating around in there at too low of a mileage to chance it. Plus another perk of the Track Pack, no Limited Slip additive required since it has a Torsen T2 diff from the factory.
Originally Posted By: bdcardinal
On my mom's 00 Grand Marquis and both my 95 and 14 Mustang GTs there is no interval, only to change when submerged.
Ditto. Then again, it depends entirely on the operating conditions. Differential fluid ends up evaporating where I am, and even using a 75W-140 synthetic, it's about ½ a quart low by the time it hits 25,000 miles. So I've made that my interval.
On my mom's 00 Grand Marquis and both my 95 and 14 Mustang GTs there is no interval, only to change when submerged.
Ditto. Then again, it depends entirely on the operating conditions. Differential fluid ends up evaporating where I am, and even using a 75W-140 synthetic, it's about ½ a quart low by the time it hits 25,000 miles. So I've made that my interval.
Originally Posted By: Falcon_LS
Originally Posted By: bdcardinal
On my mom's 00 Grand Marquis and both my 95 and 14 Mustang GTs there is no interval, only to change when submerged.
Ditto. Then again, it depends entirely on the operating conditions. Differential fluid ends up evaporating where I am, and even using a 75W-140 synthetic, it's about ½ a quart low by the time it hits 25,000 miles. So I've made that my interval.
does it vaporize out the vent . Holy Cow ! No, that's India. ;D The Rat has an open 8.8 diff . I was told that regular old 80 w 90 was FF back then. Typical Ford thriftiness, doesn't allow a drain plug, so it gets checked when I top off the front end which does leak and is even more of a pain to fix than any rear end. So far so , good. The Ranger replaces my Grand Wagoneers.They had drain plugs on their diffs.
Originally Posted By: bdcardinal
On my mom's 00 Grand Marquis and both my 95 and 14 Mustang GTs there is no interval, only to change when submerged.
Ditto. Then again, it depends entirely on the operating conditions. Differential fluid ends up evaporating where I am, and even using a 75W-140 synthetic, it's about ½ a quart low by the time it hits 25,000 miles. So I've made that my interval.
does it vaporize out the vent . Holy Cow ! No, that's India. ;D The Rat has an open 8.8 diff . I was told that regular old 80 w 90 was FF back then. Typical Ford thriftiness, doesn't allow a drain plug, so it gets checked when I top off the front end which does leak and is even more of a pain to fix than any rear end. So far so , good. The Ranger replaces my Grand Wagoneers.They had drain plugs on their diffs.
Originally Posted By: bdcardinal
'00 Grand Marquis and both my 95 and 14 Mustang GTs there is no interval.
Your stang and mom's GM are same as I posted above for the OP. Unless you are using a non-synthetic.
'00 Grand Marquis and both my 95 and 14 Mustang GTs there is no interval.
Your stang and mom's GM are same as I posted above for the OP. Unless you are using a non-synthetic.
It may not have an interval, or it may have a very long interval, but changing it now will prevent needing new oil seals and bearings in the future.
Many Fords would leave the factory with 80w90, and have a TSB recommending 75w140 synthetic. Don't bother buying Motorcraft fluid, because any synthetic 75w140 will do the same job for less money.
Many Fords would leave the factory with 80w90, and have a TSB recommending 75w140 synthetic. Don't bother buying Motorcraft fluid, because any synthetic 75w140 will do the same job for less money.
I just changed the rear end fluid in my 2014 Mustang GT because I added a Ford aluminum finned axle cover. The car only had 3,198 miles on it and the factory fluid was already a gray color. I added 2 qrts of Motorcraft 75W-140 fluid and 4 oz's of Motorcraft friction modifier. My car has the limited slip axle in it.
Wayne
Wayne
Originally Posted By: wtd
I just changed the rear end fluid in my 2014 Mustang GT because I added a Ford aluminum finned axle cover. The car only had 3,198 miles on it and the factory fluid was already a gray color. I added 2 qrts of Motorcraft 75W-140 fluid and 4 oz's of Motorcraft friction modifier. My car has the limited slip axle in it.
Wayne
How do you like that cover? It came stock on my car. I was planning on dumping the factory fill in the diff at my first oil change. It would be interesting to see how the fluid looks on a Torsen unit vs. the clutch type limited slip.
I just changed the rear end fluid in my 2014 Mustang GT because I added a Ford aluminum finned axle cover. The car only had 3,198 miles on it and the factory fluid was already a gray color. I added 2 qrts of Motorcraft 75W-140 fluid and 4 oz's of Motorcraft friction modifier. My car has the limited slip axle in it.
Wayne
How do you like that cover? It came stock on my car. I was planning on dumping the factory fill in the diff at my first oil change. It would be interesting to see how the fluid looks on a Torsen unit vs. the clutch type limited slip.
Originally Posted By: bdcardinal
Originally Posted By: wtd
I just changed the rear end fluid in my 2014 Mustang GT because I added a Ford aluminum finned axle cover. The car only had 3,198 miles on it and the factory fluid was already a gray color. I added 2 qrts of Motorcraft 75W-140 fluid and 4 oz's of Motorcraft friction modifier. My car has the limited slip axle in it.
Wayne
How do you like that cover? It came stock on my car. I was planning on dumping the factory fill in the diff at my first oil change. It would be interesting to see how the fluid looks on a Torsen unit vs. the clutch type limited slip.
Isn't the ford friction modifier that's made for their diffs a grey colour?
Originally Posted By: wtd
I just changed the rear end fluid in my 2014 Mustang GT because I added a Ford aluminum finned axle cover. The car only had 3,198 miles on it and the factory fluid was already a gray color. I added 2 qrts of Motorcraft 75W-140 fluid and 4 oz's of Motorcraft friction modifier. My car has the limited slip axle in it.
Wayne
How do you like that cover? It came stock on my car. I was planning on dumping the factory fill in the diff at my first oil change. It would be interesting to see how the fluid looks on a Torsen unit vs. the clutch type limited slip.
Isn't the ford friction modifier that's made for their diffs a grey colour?
I like the cover. It's stronger than the factory cover, will help in cooling, and just looks better. I would also be interested in how the fluid looks in your axle.
I thought that when I was reading my owner's manual, it said the friction modifier was supposed to be added to the limited slip and torsen axles. I will have to go re-read the manual.
The Motorcraft friction modifier is green in color and not gray. I would assume that the breaking in of the axle caused the factory fluid to turn gray but that's only a guess. I'm glad I changed it just to be on the same side.
Wayne
I thought that when I was reading my owner's manual, it said the friction modifier was supposed to be added to the limited slip and torsen axles. I will have to go re-read the manual.
The Motorcraft friction modifier is green in color and not gray. I would assume that the breaking in of the axle caused the factory fluid to turn gray but that's only a guess. I'm glad I changed it just to be on the same side.
Wayne
Originally Posted By: andyd
does it vaporize out the vent . Holy Cow ! No, that's India. ;D The Rat has an open 8.8 diff . I was told that regular old 80 w 90 was FF back then. Typical Ford thriftiness, doesn't allow a drain plug, so it gets checked when I top off the front end which does leak and is even more of a pain to fix than any rear end. So far so , good. The Ranger replaces my Grand Wagoneers.They had drain plugs on their diffs.
Pretty much. Factory fill on mine was Motorcraft 75W-140, which is what it also specs on two tags attached to the bolts on the cover.
does it vaporize out the vent . Holy Cow ! No, that's India. ;D The Rat has an open 8.8 diff . I was told that regular old 80 w 90 was FF back then. Typical Ford thriftiness, doesn't allow a drain plug, so it gets checked when I top off the front end which does leak and is even more of a pain to fix than any rear end. So far so , good. The Ranger replaces my Grand Wagoneers.They had drain plugs on their diffs.
Pretty much. Factory fill on mine was Motorcraft 75W-140, which is what it also specs on two tags attached to the bolts on the cover.
Originally Posted By: wtd
I like the cover. It's stronger than the factory cover, will help in cooling, and just looks better. I would also be interested in how the fluid looks in your axle.
I thought that when I was reading my owner's manual, it said the friction modifier was supposed to be added to the limited slip and torsen axles. I will have to go re-read the manual.
The Motorcraft friction modifier is green in color and not gray. I would assume that the breaking in of the axle caused the factory fluid to turn gray but that's only a guess. I'm glad I changed it just to be on the same side.
Wayne
It does say to add it to a Torsen, but there is no need. The additive is for the clutches, but there are no clutches in a Torsen.
I like the cover. It's stronger than the factory cover, will help in cooling, and just looks better. I would also be interested in how the fluid looks in your axle.
I thought that when I was reading my owner's manual, it said the friction modifier was supposed to be added to the limited slip and torsen axles. I will have to go re-read the manual.
The Motorcraft friction modifier is green in color and not gray. I would assume that the breaking in of the axle caused the factory fluid to turn gray but that's only a guess. I'm glad I changed it just to be on the same side.
Wayne
It does say to add it to a Torsen, but there is no need. The additive is for the clutches, but there are no clutches in a Torsen.
Ok, I didn't know that. I wonder why they say to add it?
Wayne
Wayne
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