mikeho

I just had my 60K service done by Exact Motorsports in Milpitas, CA. I was telling them of my transmission issues (the same that everyone else with an MT experience here on the forums). They recommended that the oil get switched to Red Line MT-90.

I already had the short shifter kit which made a little bit of difference, but the oil made an incredible impact on increasing the smoothness of the transmission. I'd have to say that it's much better than it was before, so I wanted to recommend to every IS250M owner on the forums to ask your service shop to use this oil the next time you get your car serviced. Or if you can't wait, go get it now.

I'm going to guess that Lexus dealerships won't use something that isn't factory-spec, but from my recent experience, it's better to go somewhere that's cheaper than the dealership. Especially if your car is already out of warranty like mine is.

http://www.redlineoil.com/products_g...7&categoryID=7

SwooshICE

you are talking about the unsmoothiness from 1st to 2nd rite?

mikeho

Yes, mostly from 1st to 2nd, but since I got to 60K, I've noticed some sluggishness for the rest of the gears too. This cleaned it up pretty well. I was suspecting that the viscosity of the factory transmission fluid was an issue, since they replaced it three times under warranty, to no effect.

kickin8

iTrader: (1)

you need API GL5 oil.....

I used Mobile 1 75W90....works pretty good

tieu

so whats teh best oil, im gonna do a change.. mine is pretty ****ty

08 with 12000 klicks

mikeho

Try out the one I suggested. It should make things better. One thing he noted when I picked up the car. He said that when the car is cold, it's going to feel the same as stock, but once it warms up, it should be smoother. I've noticed that behavior as well.

lobuxracer

iTrader: (2)

The differential oil? Please say no. Gearboxes don't like differential oil - it has sulfur based EP additives that kill synchros. Make sure the oil you buy says it is for transmissions!

kickin8

iTrader: (1)

I found this from the manual....please advise....thanks!

Manual transmission
Gear oil capacity -- 1.9 qt. (1.8 L, 1.6 Imp.qt.)
Gear oil type -- API GL-5
Recommended gear oil viscosity -- SAE75W-90

mikeho

I don't know much about differential oil and so on, but I looked up the oil and found this: http://www.mobil.com/USA-English/Lub..._LS_75W-90.asp

Looks like it meets API Gl-5/MT-1 specifications. Note it says GI, not GL.

The Red Line MT-90 is specifically for manual transmissions.

kickin8

iTrader: (1)

never heard of GI tho ?

can someone shed some light please?

what's the difference between GL-4 and GL-5?

what's the difference between GL-5 and MT-1?

From Mobile 1 website:

Mobil 1 Synthetic Gear Lubricant LS 75W-90 meets the most severe API Service MT-1 and GL-5 EP gear oil service classification.

mikeho

LoL.. I see that line. Looks like there was a typo in the box that I was reading off of on the same page.

hothummer

I just read on another forum that to properly change the tranny oil, it is more than just draining and replacing the 1.5L from the pan. There is also oil in the valve body, torque converter, lines etc that needs to be drained.

If I want to completely drain the fluid and replace with Redline, can a private mechanic do this or am I stuck going to the stealership?

mikeho

Private mechanic should be able to do it as long as they know what they're doing. I took mine to a private shop.

Kurtz

iTrader: (1)

The original poster is asking about a -manual- transmission.

You are asking about an -automatic- transmission.

It's not possible to change all the fluid in an automatic on the 2IS, no matter who you take it to. The transmission is designed never to have the fluid changed.