How can I tell when the manual transmission fluid needs to be changed?
I tried changing it today, but the filler bolt is stuck. Drain bolt broke free with ease. The one drop that seeped out looked clear and clean. However I´m the 3rd owner and the fellow before be didn't change it. He drove it for about 40k before selling it to me.

What´s the best way to break the filler bolt free? It´s really seized on there.

 

Do you have the room to use an impact driver? Once you get it off don't tighten it down finger tight then maybe snug it with a wrench. A box end wrench (long) If you have to use you foot. Be sure to set the park brake.

 

How about giving it some heat with a heat gun?

 

Drive up on ramps or otherwise raise the car, then use a long wrench from underneath. Car must be level in order to properly check if it is full though.

 

The Haynes repair manual says to change your manual transmition fluid every 30000 miles or 24 month. As for the bolt, I have seen a lot of success using GMCs brand of penetrating fluid and letting it soak for a while. I guess most penetrating fluids would do the job.

 

On that note, what are symptoms of gear oil that needs to be changed? I have 200,000 and based on the condition of the plugs it probably never has been changed.

I always heard that you do not have to change it unless there is problems. Essentially, during a tune-up or every so often, take the fill plug off and be sure it is full. If not, add some - but nothing about changing it.

 

You want change transmission oil before you feel symptoms of gears going bad or shifting hard or something like that. It's called preventive maintenance.
Transmission oil for Civic is engine oil, not gear oil. I do maintenance on piston engine aircrafts, buy engine oil by the cases. On those boxes, there are date codes specify the oil to be used by, it's like "shelf-life", "expiration date".

Changing transmission oil is cheaper than changing transmission.

 

Mostly you're changing it to get rid of the water and other contaminants that accumulate in the gearcase over the years. At 200,000 miles it's certainly due.

 

Yeah, I had planned on changing it out anyway this weekend, but it started raining pretty hard all weekend and I have no garage

Thanks for the info!

Mike

 

If you had water contamination in the transmission, you'll be making mayonnaise in no time. It is not pretty.