Rep Power: 0

1997 Honda Civic DX - 169,000 miles - Commute car

At my first recommended, and subsequent, manual transmission fluid changes, I used Castrol 10w40 motor oil, because money was tight, and I had read somewhere that you could. I haven't had any problems, but I'm about to replace my clutch for the first time (release bearing is noisy), and now I'm wondering:

1. Should I go back to Honda MTF, or stay with the Castrol?

2. Have I f**ked my tranny? (please have fun with this one)

Your wisdom is needed.

 
Rep Power: 518

If it shifts ok and you don't have very cold weather to deal with, I suppose what you've been using has been fine so far. (Doesn't it call for 5w30 or 10w30 though? I did not look it up.)

If you ever have to deal with cold weather, the thicker oil might cause it to not shift easily especially while cold....usually affecting 1st and 2nd gears more than the other gears until it's been driven long enough to heat up the trans fluid.

Personally, I'd use Hondas manual trans fluid. It is correct for the car, without question. It's only a couple quarts.

 
Rep Power: 142

Something to consider with that generation of civic is the fact that they are prone to noisy bearings. A thicker oil in a warm climate might supply better lubrication and might prevent the bearing wear/noise that is so common.

 
Rep Power: 0

Thank you EZONE & MCNOOPLE!