Trans Fluid: Honda, Torco, Motul, Amsoil, Redline, or any other high quality MTF
Trans Drain: 94109-14000
Trains Fill: 94109-20000

Diff Fluid: Amsoil, Torco, Motul, Redline, or any other high quality 75w90/110/140 (they all work despite some that complain about the SAE90 vs 75w90 effective weight differences. If you tend to track it more often than not, look for a 110 or 140 weight)
Diff Drain: 90401-PCZ-003
Diff Fill: 90402-PCZ-003

You can use the same pump with the trans and diff fluid. However, they're so cheap, and it's just good practice to have separate pumps for each fluid you deal with in general.

 

Awesome. Thanks for the part numbers. I'm using a low profile jack and stands. What is the best forward jack point? or should I just use the scissors jack front location(s).

 

Lots of threads on jacking and jack stands. Do a search.

This car has center jack points front and rear. Rear is the diff. Front there is an obvious frame center jack point. But its kinda far back. Even a low profile extended reach jack may not reach it, especially if lowered at all.

Some make home made mini ramps outta 2x6 to drive up on, then jack. I prefer a second small trolly jack, which i use to jack from the side, front rocker pinch weld jack point, to lift enough to get main trolly jack to reach center jack point. I find this faster and more convenient, and extra jack has other uses.

Obviously use jack stands, follow safe car lifting protocols. Error can be deadly.

 

I loved doing tranny fluid change from above the engine bay with a funnel and clear hose, I never go under the car that way. I jack up the driver side just enough to reach the fill and drain bolts, I then drop the car on level ground, and then fill from above with funnel and clear hose. Then jack up just enough to get fill bolt tightened. I can reach the tranny bolts from the driver side without putting myself in a dangerous situation and no jack stands needed.

I filled the diff like that once but the fluid I was using was so thick it took too long, and I went back to pumping it in the diff, and jack stands used for that process.

I'm not a fan of working under cars on jackstands ,but I will do it and I will take extra safety measures when I do it - four jackstands, jack positioned for extra safety, and wheels under the rockers just in case.

 

I use this "big syringe" for filling diff and trans:

https://www.pressol.com/schmiertechn...7/i/3364/12907

Cheap and does a good job.

I use amsoil 75w-110 GL5 in the diff and my trusty german ROWE 75w-80 GL4 in the transmission.
If you want, give the Liqui Moly gear oil additiv Nr. 1040 a try. Dont overdose it, 1 tube is enough. Makes shifting noticeably smoother.

 

Having a well bled hydraulic system and doing regular yearly transmission fluid oil changes I feel is the best way to keep the transmission shifting slick. A Japanese engineer once told me to change transmission fluid every 12k miles for best results. I tend to agree with him, Honda MTF seems to start degrading ~4-5k miles. To me, nothing shifts better than brand new fluid and a well bled hydraulic system.

 

Long discussion on the S2000 spec of SAE 90 GL5 hypoid gear oil for the differential several months ago.

Turns out the SAE 90 viscosity spec has changed since our cars were built. What is marketed today as SAE 90 has a viscosity at the lower (thinner) end of the old scale. I recall the upper half of the old 90 viscosity scale is now covered by SAE 110 gear oil. A multi grade like Amsoil 75W-110 GL5 fits the spec. I must be using it as there's a full bottle and a tiny bit left in an opened bottle of it in my S2000 oil stash.

The advisability of excessively thick oil (75W-80!) in the gearbox is highly questionable since the spec is basically the same as the engine oil with some "additives.":(Everyone's owners manual.)
-- Chuck

 

One way to "soften" the extremely viscous diff fluids (I use Amsoil 75/110) is to warm up the bottle in hot water. Makes pumping easier.

 

The Torsen is stout from a fluid point of view (as in the fluids it can handle, not necessarily the torque it can handle). It can handle w90 up to w140. They all slightly affect its locking capabilities and can be used as a tuning device at the track depending on what you're looking for.

More importantly - who said to put 75w80 in the transmission?

 

Thanks again for the tips on jacking the front. I think I will go with the Honda fluid for the trans. The thread kind of jogged my memory about the 1-2 shift issues (regarding synchro's and brass parts). I remember way back the discussion of using GM fluid and Royal Purple as well. GM has probably changed their formula by now. -John