Does rear diff have a reusable gasket?

[Exomodo]

Can you tell us were you learned this.

Upon performing a search, I haven't found evidence this is true, but there is mention of differing synthetic bases "reacting and dropping solids", so it's possibly not just hearsay...
Edit: found another source that says mineral oils, polyalphaolefins and ethers seem to play well together, where polyglycols or polyethyleneglycols can react with other types and form gum gels.

Sponsored

 

[Happy]

For the rear differential, Ford does spec their own "Premium Synthetic Hypoid Gear" oil.

 

[Tonka Bronka]

Upon performing a search, I haven't found evidence this is true, but there is mention of differing synthetic bases "reacting and dropping solids", so it's possibly not just hearsay...
Edit: found another source that says mineral oils, polyalphaolefins and ethers seem to play well together, where polyglycols or polyethyleneglycols can react with other types and form gum gels.

I can’t speak for other brands but I do know that Amsoil synthetic fluids are compatible with conventional products. Even though synthetics have been available to the general public since 1972 (military use even longer) there are still many beliefs, some true, some not, about synthetics.

 

[Exomodo]

I can’t speak for other brands but I do know that Amsoil synthetic fluids are compatible with conventional products. Even though synthetics have been available to the general public since 1972 (military use even longer) there are still many beliefs, some true, some not, about synthetics.

As one of the commentary stated in one of the half dozen discussions I read earlier, when in doubt, scoop some of the fluid you just emptied out of the axle into the cap of your new oil and squirt a little new oil into that, mix and pause for nothing (or something) to happen... either it sets up into a custard or it just sits there, staring at you, waiting.

 

[goatman2]

I believe Ford specs a synthetic gear oil for their Bronco differentials and the cost between synthetic and conventional gear oil for a couple of quarts is negligible. As far as regular changes regardless of oil type, it’s been my experience that once the initial mating wear materials are removed and a quality diff fluid is installed, the fluid always looks clear when checked on a regular basis. Can you elaborate on why CE would void a warranty if synthetic oil is used in their diffs? Thanks.

I tried to find what Ford spec'd for the Bronco but didn't find it, since I know Ford uses synthetic gear oil in other applications. I threw that out there as another perspective, since so many things around topics like this are speculative with little real hard studies or info. Currie requires conventional oil with a GL-6 rating for higher pressure resistance, and they say that current synthetics are GL-5 rated, which in their opinion is less desirable in the 9" style rear ends that they build, yet they say the same thing for the Dana 60/70 based RockJock rear ends that they build. My point was simply not to assume that a synthetic gear oil is better or superior to conventional gear oils.

Regarding Ford using synthetic gear oil I know they spec synthetic oil in Super Duty pick ups, and we rebuild quite a few (relatively, not very many in pure numbers) failed rear ends in Super Duty trucks. What I see happening, and this applies to quite a few situations, is the factory uses synthetic to extend service intervals as a selling feature. In the real world when vehicles get over 100k miles fluids should be changed due to wear no matter what, but because of the synthetic it doesn't get serviced, and can eventually cause a failure. To add some context here, I worked at dealerships for 29 years, and now have owned my own independent auto repair shop for 11 years, so I've seen it all.

Factories more and more are putting out "lifetime" fluids and parts. Modern vehicles are too well built, and cost too much to replace, and can and will be driven for multiple hundreds of thousands of miles and nothing on the vehicle is truly lifetime. One example is u-joints which on all vehicles now are non-serviceable. We insist on replacing u-joints on any rear wheel drive vehicle over 150k to prevent drivelines from falling out on the road, which has happened many times. We recommend replacing engine oil and rear end gear oil because the oil collects contamination even if the synthetic oil maintains it's properties longer than conventional oil. To me, if the synthetic lubricates better, then don't loose that benefit by negating that effect by running it longer with some contaminants in the oil. If there is to be a benefit, change it more often, otherwise the only benefit is not needing to service it as often. And, you can pay twice as much for a synthetic service, so do two conventional services or one synthetic service. I'd rather have two conventional services and have cleaner oil for half the time. Point is to service synthetic oils more frequently than the factory recommends, to actually get a benefit from using the synthetic oil.

I know this is long, forgive me is this is boring, but here is another example. I have a friend with a Ford Powerstroke truck, and he swears by Amsoil oil. He doesn't change it very often, like 80-100k miles, but he regularly takes a sample and sends it off for analysis, and he changes the oil when the analysis says it's time. He has replaced his turbo 3 times, at 150k intervals. I drive Powerstrokes, and know tons of people who drive Powerstrokes, and read forums, etc. No one else that I see has to replace a turbo every 150k miles, and virtually everyone with a Powerstroke uses Delo or Rotella conventional oil. He is so sold on Amsoil that he won't consider that the much longer service intervals are his problem. He says "well I get it analyzed". Pretty simple to see.

 

[Tonka Bronka]

I tried to find what Ford spec'd for the Bronco but didn't find it, since I know Ford uses synthetic gear oil in other applications. I threw that out there as another perspective, since so many things around topics like this are speculative with little real hard studies or info. Currie requires conventional oil with a GL-6 rating for higher pressure resistance, and they say that current synthetics are GL-5 rated, which in their opinion is less desirable in the 9" style rear ends that they build, yet they say the same thing for the Dana 60/70 based RockJock rear ends that they build. My point was simply not to assume that a synthetic gear oil is better or superior to conventional gear oils.

Regarding Ford using synthetic gear oil I know they spec synthetic oil in Super Duty pick ups, and we rebuild quite a few (relatively, not very many in pure numbers) failed rear ends in Super Duty trucks. What I see happening, and this applies to quite a few situations, is the factory uses synthetic to extend service intervals as a selling feature. In the real world when vehicles get over 100k miles fluids should be changed due to wear no matter what, but because of the synthetic it doesn't get serviced, and can eventually cause a failure. To add some context here, I worked at dealerships for 29 years, and now have owned my own independent auto repair shop for 11 years, so I've seen it all.

Factories more and more are putting out "lifetime" fluids and parts. Modern vehicles are too well built, and cost too much to replace, and can and will be driven for multiple hundreds of thousands of miles and nothing on the vehicle is truly lifetime. One example is u-joints which on all vehicles now are non-serviceable. We insist on replacing u-joints on any rear wheel drive vehicle over 150k to prevent drivelines from falling out on the road, which has happened many times. We recommend replacing engine oil and rear end gear oil because the oil collects contamination even if the synthetic oil maintains it's properties longer than conventional oil. To me, if the synthetic lubricates better, then don't loose that benefit by negating that effect by running it longer with some contaminants in the oil. If there is to be a benefit, change it more often, otherwise the only benefit is not needing to service it as often. And, you can pay twice as much for a synthetic service, so do two conventional services or one synthetic service. I'd rather have two conventional services and have cleaner oil for half the time. Point is to service synthetic oils more frequently than the factory recommends, to actually get a benefit from using the synthetic oil.

I know this is long, forgive me is this is boring, but here is another example. I have a friend with a Ford Powerstroke truck, and he swears by Amsoil oil. He doesn't change it very often, like 80-100k miles, but he regularly takes a sample and sends it off for analysis, and he changes the oil when the analysis says it's time. He has replaced his turbo 3 times, at 150k intervals. I drive Powerstrokes, and know tons of people who drive Powerstrokes, and read forums, etc. No one else that I see has to replace a turbo every 150k miles, and virtually everyone with a Powerstroke uses Delo or Rotella conventional oil. He is so sold on Amsoil that he won't consider that the much longer service intervals are his problem. He says "well I get it analyzed". Pretty simple to see.

I can relate, as I have a 2007 6.0 Powerstroke with about 200K on the clock. 80K on any oil is excessive unless you’re running an additional bypass filtration system, sampling or not. I am not a diesel mechanic so when my 6.0 needed injectors, I took it to someone who is a 6.0 specialist. I have run Amsoil 15W-40 HDD since new with changes at 15K and filters at 7K. When he took it apart to do the injectors, he had never seen one cleaner. Had Ford notified all owners of the need for the injector pump blue spring kit, I probably wouldn’t have needed injectors. And no grease fittings and lifetime fill BS is a crime that will continue I’m sure. Anyway, thank you for your input and knowledge. I guess we can agree on one thing, change your fluid folks, and not just your motor oil. I feel like my Bronco‘s brake system needs bled. The second pump on the pedal seems to make more of a difference than it should.

 

[Exomodo]

Every single u-joint I've replaced on trucks I've purchased in the 100ks always had dry caps, the roller bearings had long turned to dust...

 

[FlyingScot]

Front is sealed halves but does have a drain and fill.

1. Remove and discard the front differential fill plug.

1. 
   WARNING: Be prepared to collect escaping fluids.
   Remove and discard the front differential drain plug and allow the differential fluid to drain.

Having a hell of a time getting the search function on parts pages to give me an apparent answer, am I reading it right that the fill plug on the rear and the drain plug on the front are both 6C2Z4N282AA and the fill plug on the front is E8UZ4N282A?

 

[flip]

Having a hell of a time getting the search function on parts pages to give me an apparent answer, am I reading it right that the fill plug on the rear and the drain plug on the front are both 6C2Z4N282AA and the fill plug on the front is E8UZ4N282A?

Front drain plug.

 

[flip]

Front fill.

 

[flip]

Rear fill is the same as the front drain.

 

[flip]

 

[FlyingScot]

Outstanding, thank you @flip

Will be ordering these from y'all when I get set to Redline Oil all the things except the engine.

 

[flip]

Oops. I just noticed. Look at the bold print at the top of the part section screen shot.

Non-Raptor plug is the same.

 

[FlyingScot]

Front drain plug.

Just a heads up, your system shows both those items as not compatible when I looked them up on your parts website

Sponsored