reaching 38K miles, i need to change the oil for the diff/tranny but i heard that you need to have a special kind of oil for them....I don't have the manual book so i don't know what honda recommend...let me know guys...thanks.

 

This has never been posted about before.

https://www.s2ki.com/forums/index.php?showtopic=195574

 

from what I've read, LE 607 Almasol SAE 90 is the best diff fluid.. . You can pick this up in the s2k marketplace, or hardtopguy.com. I just ordered some yesterday. For the tranny, get some GM synchromesh friction modified from a cadillac dealer, Honda MTL from honda dealer, or Redline MTL or MT-90. All should work fine. The first is probably best in colder weather, with MT-90 in 2nd.

 

https://www.s2ki.com/forums/index.php?showtopic=339817

 

Not necessarily so. LE607 is extremely thick, almost like molassus. For those who operate in climates that get near or below freezing, this would not be a good choice. Even "Road Rage", the person who first brought this fluid to our attention, stated so.
I have a diff temp monitor on my S and when the temps are below freezing, the diff can take many miles of in city driving to gain even 10 degrees and this is for a synthetic multigrade. A fluid like LE may never warm up to its operating temperature "zone" in an average city drive. Thick, cold fluid won't efficiently cover metal parts.

 

oops, guess I missed that part of the post. So should one be running synth 75w90 in the cold, and switch to LE607 in the warmer months?

 

a synthetic 75w90 from a reputable manufacturer should suffice year round in a mild climate. no need to replace every 6 months.

 

Well, this to me, seems like a lot of work, but if you wish to speak in terms of "ideal", then sure, go ahead. For those of us who live in the snow belt and continue to daily drive this car, a synthetic 75W90 has proven to be more than adequate. This would include summer track duty as well.
Granted, the LE607 is more akin to the SAE rating of the factory diff fluid and Honda recommendation although it seems to be far thicker than anything else you can put into our diffs. Use of it in colder climates wouldn't be a bad thing provided the owner realized that it takes that much longer for it warm up, so driving with less load on the drivetrain would be wise till the diff did warm up (however long that might be).

 

I've alluded to this in my last reply. However one final word of caution:

Not all synthetic 75W90 gear lube is designated "GL-5". Only this rating of fluid can be used in our diffs. Realize that gear lube involves a different viscosity rating than say, engine oil or even tranny fluid. It is possible to get a non-GL-5 fluid in a 75W90 viscosity gear lube that can mimic the viscosity of a 10W30 engine oil (my numbers here are "ball park" so please don't nit pick). You do not want to be putting such a gear oil into our diffs. My point is that without seeing the GL-5 rating, the fluid may not be meant for our rear diffs.

 

I picked up some mobil 1 synth 75w90 GL-5 for $8.