Will changing ATF mess up Transmission?

[newlano]

Hi,
I read that changing your ATF will "shock" your Auto transmission and cause pre-mature failure.The article stated that the new ATF should be gradually introduced int9o the tranny. Is this true? I have a 1991 525i and was thinking about the complete flush that places like Pep boys offers. Any of your experiences will greatly help.

[jjw]

Yes it can, especially if the ATF has not been changed regularly or long time. The trans might be holding together because the old ATF.

[Russell]

Had my indy clean screens pans and change transmission filter, DRAIN both pans in transmission (no flush) Torque convertor is not drained and new standard dexron III fluid ATF at about 73,000 miles. It was the first change and had no problems. 30,000 mile later same routine, except I use Mobil 1 Synthetic Dexron III atf. No problems, perhaps a smoother shift. My GM trany should be changed every 30,000 miles.

Just my experience.

Hi,
I read that changing your ATF will "shock" your Auto transmission and cause pre-mature failure.The article stated that the new ATF should be gradually introduced int9o the tranny. Is this true? I have a 1991 525i and was thinking about the complete flush that places like Pep boys offers. Any of your experiences will greatly help.

[632 Regal]

I wouldnt flush it but do as recommended, change the filter and only replace what fluid came out...every 30k or so. If it has been changed every other oil change than of course you can change it.

[infinity5]

I don't think my transmission fluid has been changed since the car was born, but i think i'm going to go for it. i won't flush it, but i'll change the filter and whatever fluid drains out.

I'd kind of a littel skeptical of this whole idea of killing the transmission by changing its fluid just becuase it hasn't been done before.

[632 Regal]

I have seen transmissions fail from shocking it with new fluid...its real and NOT a hoax.

[dacoyote]

I have seen the shock of the flush kill tranny's... you need to change a part of each time..

-Charles

[gtopaul]

We don't do transmission fluid changes or filter changes at work because of the possibility it won't come off the rack when finished. I've seen it happen with just draining the fluid out of the pans and not just flushing. Every time we have to go into a trans to replace a bad valve body or something we tell the customer what could possibly happen (worst case scenerio) and let them make the choice. It's usually a bad front pump seal on the early auto trans that causes this. Tech said something about it looses it's prime when the fluid is drained. I personally think that if it's going to die it's going to die and there's not much you can do. I have 180k miles on my 92 525iT that is slow to engage reverse (about 2 seconds), and stays too long in 2nd gear before shifting. I've used the flush method on my other two cars (Volvo's) one with 142k and the other w/100k miles without any problems and they both shifted better afterwards. The 140k mile car has the ZF HP22 same as the early 525's and it was slipping badly. The flush fixed it right up and it's been fine for the last two years. I'm going the flush method and I'll be sure to let you all know the results. Hopefully next week.

Paul

[gtopaul]

Here's some good information about trans flushes.

http://www.autotransflush.com/

[Kalevera]

Paul, don't you work for a dealer? So the dealer won't do trans fluid and filter changes on cars that they sold new? That is...REALLY...suspect, albeit it affirms everything I know about them.

best, whit