After talking to a mechanic this morning, I was told that flushing the transmission fluid on a high mileage (144xxx) transmission is potentially dangerous to the transmission

Is this actually the case?

The fluid on the car I bought is thin and black and burnt smelling. Figured a whole flush and refill might alleviate some of the intermittent grinding.

Anyone have an opinion?

 

Your mechanic is in fact correct. A flush can release a lot of hard gunk that's just stuck to the case right now and plug the valve body and any filters completely. Doesn't sound like you have much to lose other than the cost of the flush, but if you're at a point of "it's making noises" you're too late in the game. Get a good used one.

 

i wouldn't be too aggressive with your maintenance there. i wouldn't do a full on flush at 144k maybe just a drain and fill. if you do pay attention to the fluid your draining out for any metal in the oil. metal chunks your sol, metal dust will make the oil sparkle a bit and is also a bad sign. if the oil just look dark and smells bad then you might be ok. if it is already shifting poorly and grinding as you stated you might be sol already tho.

 

Appreciate the replies. Taking it to a honda mechanic to do a drain and flush friday morning. We'll see if it helps! Really just need it to get me through the winter.

Fuel economy is still telling me 50+ per gallon so thats nice!

 

once the flush is complete i would HIGHLY suggest babying the car. the higher rpms you have the faster your turning the trans internals.