It's time to change my diff fluid and figure I'd do the trans at the same time.

Can I source all the fluids at AutoZone (Mobil 1?)? Or should I buy Honda diff fluid. Also, what tools (if any) would I need to buy? Fluid pump, etc.

Hard to believe, but the car is now 20 years old.

thanks for any advice.

John

 

The differential requires hypoid gear oil. "Use an SAE 90 viscosity hypoid gear oil, API service classified GL5 or GL6 only." (Owners Manual) You won't find GL6 as the classification obsolete. Multi grade that includes 90 is fine. Hypoid gear oil is critical. Some Honda-branded differential oil is for front engine cars and not suitable for the S2000 -- read the label.

Honda MTF is fine in the gearbox although other suggestions abound. I've used it and several others. Royal Purple Syncro-Max is in there now.

There are photos essays in the library on how to change both. You're gonna need little pumps or oil in squeeze bottles. Both boxes are filled until oil comes out the fill port so have rags handy.

-- Chuck-

 

Don't forget to break loose the plugs in the fill ports before breaking open the drain ports!

Diff requires odd tools (at least, I didn't already have them): you need a 23mm wrench for the fill, and a 24mm socket for the drain.

Everything else is straight forward.

 

Several well known S mechanics on this forum have said in the past that Mobil 1 75W90 gear oil has been bulletproof. That is what I use. I happen to use Amsoil synthetic MTF for the trans.

One tip for the differential is to buy a new drain (with a magnet) plug from Honda and use that for a fill replacement. That way one wrench/socket will do both and you double the magnetic capture qualities for the diff.

The copper washer is used for the fill in case the bolt is removed to verify the quantity of oil and then is replaced. Usually an aluminum crush washer is a one time use part. (Flat side of washer to the car, rounded side to the bolt)

 

I have M1 75/90 in my diff and Honda MTF in my transmission. Works great, shifts nice and smooth, etc.

I have used a fluid pump to do mine, just a cheapo hand operated one. I also found the ones below and have some of these but have not used them yet:

 

That's the pump. Get two; one each for the gearbox and diff although I'm convinced any "cross contamination" of these two oils is harmless.

They only work well on the standard 1 quart bottles, their tube isn't long enough to reach the bottom of the Royal Purple SyncroMax bottle but since it doesn't take two quarts it works.

Plan on getting messy changing these oils. Just how it rolls.

-- Chuck

 

I actually bought the two pack on Amazon but just linked the single one. They are cheap enough too so if anything happens you are not out very much! I had a little hand pump before that with an inlet and outlet hose. Issue with that was with the 1qt bottles, if you are not paying attention you inevitably knock the bottle over with the hose that is stuck down in it once the bottle gets below half full and spill oil everywhere.

I HATE gear oil with a passion. It is, in my opinion, the nastiest thing in a car so yes plan on it being a bit messy and dont wear clothes you care much about. I stepped on a container and spilled oil I just drained out of a diff onto the back of a brand new pair (As in took them out of the box, put them on and walked into the garage) of Globe shoes once ... I never got the smell out of them

 

Y'all are some reckless butterfingers.

 

LTH uses Mobil 1 75W90 gear oil for the diff and they use Royal Purple for the Trans or OEM Honda;

I have Mobil/Royal Purple very happy with both

 

Thanks for the replies and especially for the pump link on Amazon. So for trans I should go with the honda MTF? Do you by chance have honda part #'s for the crush washer(s) and magnetic plug? I'm usually lazy and reuse them.