What transmission fluid?

I'm preparing my newly purchased CRX Si for the summit racing school and I need to change the transmission fluid. Problem is, I'm not sure what the best kind is to use. What do you guys use?

I've always run Castrol 10w30... are you running a stock diff?

[QUOTE=Xian;284742]I've always run Castrol 10w30... are you running a stock

it has an OPM limited slip diff in it

I usually run a dino based 10W 30 in mine. It might not hurt to call OPM and ask if they specifically recommend something.

No special oil needed for the OPM limited slip. Just do not add friction modifier. They prefer a normal oil. I build the units for them.

My impression is that the Honda defacto standard for D series trannies is Redline MTL. I would also check with the crew at www.d-series.org (dude's online name is transzex :) - he rebuilds many IT honda trannies). Off hand, I can't speak if MTL is better or worse then regular oil in d-series trannies with an OPM LSD. Again, I would check with transzex.

I have a 92 si with Quaffe LSD and I have been using Redline MTL and Redline Lightweight Shockproof 2:1 mix for 3 years (30 AutoX, 22 track days and 12K miles - all on the same tranny) and with no problems. Smooth as a kitten...

EDIT: Transzex is "BoneSpec" on this forum as well.

Don't use Redline in the OPM/Steve diffs. I did and it turned temporarily into an "unlimited slip differential". I had to flush it twice with Castrol dino oil before it started to work again.

Honda transmission with OPM diff = Castrol 10w30 and change with the oil after every double weekend.

-Tom

Whatever fill you decide to use in your tranny, don't be afraid to try alternatives if you encounter shifting problems. I have a T-5 in my Mustang that required experimenting with several different lubricants before I found one I liked. The short of it is that every tranny is different and different uses will also have a bearing on what you eventually decide to fill your box with.

Redline MTL has a bad habit of eating thee plastic bearing cages in the older transmissions, I've replaced quite a few mainshaft and countershaft bearings years ago.



BTW, I'm Transzex on D-Series.org, also know as Mista Bone on Honda Tech and other sites.

Most of the street LSD transmissions I've built, the owners are running Pennzoil Synchromesh without issues. I know Matt Downing is using it in his ITA car, but I don't think it would stand up to the heat of an enduro car. It is 5w30 base viscosity.

I run Mobile 1 10w30. but any quality oil will work fine in the tranny. depending on the track, tranny's don't usually take a that much of a beating... I only make 8 gear change's per lap at VIR, certainly not an extreem amount of wear and tear.

We run Pennzoil Syncromesh manual transmission fluid in our Civic Si. Works great.

I always used Honda factory manual oil on my CRX.