I just changed the differential oil at 15,XXX miles. I was disgusted at how dirty it was. There was all of this thick black sludge in it and the drain plug was coated with this stuff.

For those of you thinking of doing it yourself, its pretty easy. The dealer wanted $90 bucks to do it!!! You will need a 23mm wrench (fill plug) and a 24mm socket (drain plug). I could reach the drain and fill plug without jacking the car up. I bought Mobil Synthetic Gear oil, 75W-90, GL-5 for $6.99/quart and a pump $3.99 from Kragen. Basically open the fill plug, then the drain plug and drain into a pan. Clean both plugs, replace the drain plug, torque to 33 ft-lb. Pump in the gear oil until it spills out and replace fill plug (torque to 33 ft-lb). Refill is about 0.8 quarts.

I do have a question for anyone with more experience... I changed it at 15K and it was filthy. What would be a better change interval and is the black stuff really that bad for the gears?

Thanks

 

I changed mine as you did with Mobil syn. but I did it at just over 5000 miles and the oil was clean as a whistle with very little filings on the magnetic plug. The black crud you saw is not the best thing but I've seen the insides of a lot of diffs and this is normal buildup. The magnet holds the worst bits.

 

Thanks. 5k and clean... that's good to know. I was thinking 10K might be allright. I will probably do it at 10K and check the condition.

 

I did mine at 9000 and it was clean. The original fluid looked like it might have moly in it ( gray colored ) but it was not degraded or sludgy.

 

WOW! This simple little thread has just provided valuable info. Unless there is something else at work here, we've just determined that 10K miles might be the best rear diff. oil change interval. Mind you, with synthetic oil, it may not get as grungy as normal oil. I wonder how many people are paying attention here.

 

I changed mine at 9500 and thought that maybe I shouldn't have because it looked so new and clean, but I went ahead and put Royal Purple in it. I going to switch to Mobil 1 next time.
I think every 10,000 or so is a good number. I think the owners manual says every 30,000, i can't imagine what it would like after that long.

 

I think the owner's manual actually says 15K for the differential and 30K for the transmission fluid. Its so easy to do, I will probably do both the diff and tranny at 10K.

 

[QUOTE]Originally posted by V8Eater
[B]I just changed the differential oil at 15,XXX miles.

 

Has anyone used Redline synthetic gear oil and MTL for their fluid changes? Wondering if these products will provide any benefits or worse yet cause additional wear. Or should I go with a less expensive product such as Mobil 1 or even Honda factory fluids?