Rear Differential Oil Change - How Often?
 

How often do you guys change your rear differential fluid?

I changed my first one last summer. I am thinking of changing it some time soon, but not sure if it's a time interval or certain mileage I am supposed to do it at? Even my oil changes, I do it every 4 months regardless.

I waited until 30k but I wish I changed it at 15k or 10k even. There are a lot of stuff on that magnetic .. I plan on changing it out again at 40k.

It may or may not be necessary, but I change mine once a year, usually around the holiday weekend in May. I change the transmission fluid (manual) at the same time. That works out to every 25,000kms or so.

@Bonburner...the 1st change always looks kind of scary. You wont see as much on the next changes even if you go as long on the interval. When the gears are new, they need to "take a seat" to each other, and this produces the fine particles that make up the paste that's stuck to the magnet. IIRC, I first changed mine at 1,300 miles or so, and it was already pretty grungy looking. Each change after that has had less and less material on the magnet.


My personal preference for differential fluid is Redline's 75W85 high performance GL5 gear oil. I drive the FR-S all year as my daily driver. If it was summer exclusive, or the car saw some track duty, I would consider a 75W90.

My primary concern is if there is That much gunk on the drain plug then how much gunk is still in there - more flushes will extract more gunk lol

Why not just change (clean off) the drain plug ..... ?? ..... :popcorn:


humfrz

The problem is if there is gunk on the drain plug then there is More gunk inside as well - kind of like termites .. Sure you can kill off termites in this one spot but throughout the house there're more

The magnet on the drain plug does a good job of pulling the bad stuff out of the oil.

There's no harm changing out the fluids sooner, I personally believe. It's relatively inexpensive maintenance.

When you change the Differential Oil (or even the Manuel Transmission Oil) do you guys buy new crush washers, or reuse the originals?

They're gaskets, not crush washers. You can reuse them.

http://www.ft86club.com/forums/showp...0&postcount=49

I wouldn't re-use the ones on the diff, but no problems using the ones on the transmission a couple of times.

^Yeah, the washers are cheap. I bought a few at my local dealership, came out to $1.50 each.

yes this is good thinking, see my post in the Pentosin vs Motul Thread: http://www.ft86club.com/forums/showthread.php?p=2244143#post2244143
Changed Diff fluid at 13,300 miles (21,404 km).

Oh and just remember there is no space above the fill plug, none! Bottles can be positioned only horizontally. I had to squeeze the hell out of 2 Motul bottles to get it to fill. And finally realized there is an inverted nipple in each bottle that can pulled out for better filling. Torque setting is higher for the Diff Plugs, so I used new crush washers.

No. Your logic is flawed because you missed the main point of the magnetic plug. The gear teeth lap against each other during break-in. The magnet pulls the tiny steel particles out of suspension - permanently. There are no other termites in the house

The only reason to change the gear oil would be out of concern for viscosity breakdown, not pest control.