2017 Honda Civic, 55,000 miles, maunal transmission
I recently replaced the transmission fluid in my car with automatic transmission fluid, instead of manual transmission fluid. I have always bought my fluids from the same Honda dealership ever since I bought my car and so I assumed that I had been given the correct fluids. Later, when I was returning the unused transmission fluid, I found out I had used the wrong fluid. My mechanic also didn't catch this mistake. The Honda parts clerk (who is the same person I buy my fluids from) said that I would have to replace the transmission fluid with the manual transmission. Is he correct?
I'm asking because the automatic transmission fluid cost $30/bottle vs manual tranmission fluid $15/bottle, not to mention the cost of having to pay again for the labor to redo this job. I was very upset at first with the parts clerk and then at my mechanic, but I learned a lesson that I'm responsible in the end for knowing what my car needs. I'll never make that mistake again.
I did read through a few very long posts on your forum about transmissions, but couldn't find an answer to my particular question My Civic is shifting fine. So I'm wondering if the more expensive automatic transmission fluid will indeed damage my manual transmission and do I need to replace it. I would appreciate another opinion on this matter. Mahalo
You will eventually damage your manual transmission if you leave that in there. Automatic transmission fluid is much thinner than manual transmission fluid - a manuals are more akin to a gear oil than thin fluid. ATF is designed to be pumped by an automatic transmission's pump and designed to go through a vehicle's valve body efficiently - none of that is in a manual.
My old Ranger's rear differential contained 80W-90 gear oil and was quite viscous-almost like syrup. Manual transmissions cool themselves via splash lubrication, which requires heavy oil.
Thank you - I will replace the fluid.
why don't you let the mechanic source the fluid?
