Differential Front & Rear Fluid

Doesn't matter. The quality of the Amsoil will do better in cold than basically anything else.

 

I changed my rear diff oil at 1500 miles out of ‘shear’ curiosity. There was a 1/4” thick layer of grey sludge on the drain plug magnet with plenty of metal metal shavings. Replaced with Amsoil

$28 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90. Will do the next change at recommended interval.

Bought the truck at a dealership 250 miles away. But I did two 20 minute in-town runs with an hour cool down after each one before taking the highway back home. Drove mostly under 60mph. Differential does not howl…quiet as a mouse. I intend to hit 300k miles with this truck. I’ve had an F-150 rear end start howling at 60k…it was the stout 9.75” diff but I took to the freeway right off the dealer lot.

 

Do our 3rd gens come from the factory with synthetic in the diffs?

 

So many threads on this but I think this is the most recent. Seems consensus is any synthetic 75-90 in the diffs, 1 qt Japanese Liquid Gold (Toyota LF) or Ravenol substitute, Red Line GL4 MT 90 in manual trans.

I am about to DYI. Anyone know what the 'easiest' way to refill are? Those 'flexi' bags 75-90 comes in? What about getting oil out of the can and into the T Case?

Is there a decent transfer pump that wont fail and wont cost a ton either?

Last time I did this was on a Dana 60 in a 1970 F250 Highboy 1992 in the dead of winter.

 

Amsoil flex bags are great. They’re a similar price to any other synthetic like Valvoline.

 

85-140 conventional here too. No whine runs smooth and quiet.

 

Flex bags were great until the hose/spout connection disintegrated on me. Had to hold the bag’s spout into the fill hole and that was so messy. Always a little left in the bag so I’m gonna try the Slippery Pete pump next time. The rear diff and transmission refills were otherwise very easy to do.

I used Amsoil 75-90 and diff is quiet. “Shhhh, hear that?” “Hear what?”…”Exactly!”

I must say: Redline MT90 does make the shifting much smoother…I mean, really smooth. I know it sounds like hyperbole…but it’s true. The most noticeable ‘upgrade’ done to the truck so far.

 

they replaced my rear differential at 29k miles due to "excessive bearing clearance". changed diff fluid at 500 miles with amsoil severe gear 90 weight. not sure if it's related to the fluid though or just bad setup from the factory. never towed or carried any heavy loads either.

 

Very sorry to hear that. No way to know for sure what happened. I doubt it was simply the fluid change. Most damage to the bearings or rear diff probably happens with excessive heat during the first 100-200 miles. It could also have been defective from the factory as you mentioned. I had a 1993 Toyota that I never babied, drove it from New Jersey to San Jose towing a 12ft. trailer. That diff was as quiet as a mouse and did 108k before I sold it. I changed my current Toyota rear diff gear oil to Amsoil

$28 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 Sever Gear oil at 1400K miles...fingers crossed...but not going to worry about it.

 

Ravenol

 

What would a reasonable intervals be for changing the gear oils in the
Differentials and transfer case. I'm at 28,000 miles now. I see some say 30,000 miles some say longer. I mostly drive on the roads, nearly no Off-roading and tow a 1500 pound pop-up afew times a year. My usage isn't in pushing the truck too much that often. With winter coming and no Garage to work in doing it myself at 30,000 when that comes around is not gonna be fun. What interval do most of you change it at?

 

I did the initial change at 30k, was black and gross. Changed again at 60k and it looked brand new. I’ll do it again at 160k.

Once you get the nasty break in fluid initial fill out and put in a high end synthetic you can almost forget about it. That’s my opinion.

 

i changed my diffs at about 15K because i met the requirements outlined in the manual. the fluid wasn't bad looking and there was not much build-up on the magnetic plugs. based on that, i would feel comfortable going to 30K miles between changes especially if most of what i did was on-road and not hauling or towing.

i recently changed the MT fluid at 25K miles. it did not look bad either. t-case fluid looks Ok and was not changed although i have a can of fluid from toyota and may do it if i get a pump.

regarding the diff and MT fluid, i used amsoil severe gear

$28 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 GL5 in the diffs and manual transmission 75W-90 GL4 in the MT. it made no difference whatsoever in noise, felt performance or shifting. i would feel comfortable using any brand provided the weight and GL rating are what is recommended.

 

I have an Automatic trans so that has different needs. I will have to just find a place to work indoors or do it before it's too cold to work outside. I assume that Valvoline or any synthetic 75w90 I can buy local or on Amazon is good enough for the front and rear. I acquired some Redline MT-LV for the transfer case which is one of the substitutes that has been said is quite acceptable and less expensive. MT-LV is GL4 also. I'm assuming that if I have the TRD skid plate that has to come off to access the front Diff and transfer case.

 

So the Factory fill is most likely not Synthetic gear oil I'm guessing.

 

It is. Doesn’t mean it doesn’t get dirty or get metal particles in it off of a new diff.

 

No idea, but it get pretty torched in the first 30 000 as the diff breaks in. After the diff is completely broken in, aside from possible water contamination, a fresh fill of premium synthetic will last a long long time.

 

Well that's helpful. I will try to do them as close to 30k as possible. nice to know I can extend it with quality oils after and it will stay cleaner.

 

Your post prompted me to change mine at 15K miles. I had the sludge and plenty of metal shavings on the magnet too. It is so easy and cheap to DYI. I lowered my spare for a little more access.

I am not sure if the sludge and metal actually reduces longevity (plenty of diffs spinning 200K with OEM fill), but common sense tells me it is good to get it out. I used Valvoline flex fill bags I just bought on Amazon and new crush washers. Nothing super exotic. Seems to me that an early initial change to get the crud and metal out is good but then settle into a normal interval.

 

What is the capacity for the 2016 TRD sport diffs ??