Most cars never get their transmission fluid changed and arrive at the junkyard on their factory fill
Can't change my own or I'll get a condo letter. This is what my shop calls a flush, I think. Should probably get more details next time.Are we talking about a fluid exchange vs a drain and fill?
I've heard the term transmission "flush" used quite often and I kind of think that's a misleading term.
A fluid exchange should be harmless and the most effective way to replace transmission fluid. They're designed such that the amount taken out and replaced is exactly the same.
The only potential issue is if you started off with the level low or high, you're going to end the same way.
For the DIYer, if your transmission has an easy means to drain, refill and verify level, a simple drain/fill or serious of them is what I do.
Yes, the reason they "recommend" a flush is because it a way to make money especially the BG flush. Shops typically charged 120-180 bucks, which means 100-160 buck profit for the shop. When I was a manager at a national chain i was told to sell flushes on every vehicle. Its unecessay a d&f is fine but not as profitable. Also BG incentivizes mechnaics and shops to use their products by placing "coins" of different values in their product which can be redeemed for cash. So the more product you "recommend" the more money a tech can get. Thats kinda shady dont ya thinkNobody recommends a machine flush, except BG (a snake oil company) and Jiffy Lube and similar quick lubes
One drain-and-fill every interval recommended by the mfr is sufficient
If you really need to drain more than that, the best way is to just do 3-4x drain and fills, the interval in between which can be anywhere from a short drive around the block to thousands of miles. And even then, this is rarely necessary unless you went like 200k without ever changing the ATF, or if you used the wrong fluid.
Most cars never get their transmission fluid changed and arrive at the junkyard on their factory fill