Tranny Question?

[mauricioespana]

I read a post from someone on this forum about someone (Wayne R. Dempsey) who was having a problem with their tranny which was solved by replacing the transmission fluid that turned out to be low. I am having exactly the same tranny problems described in that article. I took my 92 325i to a tranny shop so that they could change the fluid, but the guy recommended that I not do it because there was a "good amount" of metal in the pan so he claims changing the fluid will make things worse. I was told by another bimmer owner that he was told the same thing, but BMW told him it was normal wear and his car has been fine after changing the fluid. If either Wayne or anyone who has had a similar experience could give me some insight as to whether I should go ahead and change the tranny fluid or not.

Thanks in advance.

[blkongry]

Are we talking a manual or auto... I'm guessing a manual? There are a few things you can do. First, you should change your fluid... most definitely. If you have metal in the pan, why not flush the tranny try and get out as much as possible. There is no sense in leaving it in there and just continuing to drive it. Use a good synthetic ATF fluid like Mobil 1. To help flush the tranny, drive it right before you change out the fluid. That will aggitate any debrit, mix it up in the fluid, and hopefully get a lot of it out when you drain it.

You can also neck-down a tube and rig it to your wet-dry vac to suck out as much residual tranny fluid and metal flakes as you can... that'll help, but you'll have an oily vac when you are done (of course, you probably can't get the tube very far down in the tranny). Or, you can use a flex line with a strong magnet on the end... swab around in the tranny if you can through the lower drain bolt opening and see what debris you can get out (again, probably won't be able to get very far in there). Lastly, which is probably the most effective trick, along with changing the fluid, affix a strong flat permanent magnet to the bottom of your transmission. This keeps all the flakes and any other metal (steel) debris from getting ground through your gears. It's an old racing trick so when you broke a tooth or something you didn't suck it back up into the gearing and garble the rest of your tranny. Either way, yeah... you should change your fluid... auto or manual.

[mauricioespana]

Thanks for replying. My car has an auto tranny. Do you still recommend changing the fluid?

[blkongry]

Yes, definitely replace fluid, since it is hydraulic fluid and takes the drive load. But with an auto tranny, can't they just drop the main pan and clean out the metal flakes.? I recant going to synthetic with an auto unless you thoroughly flush the tranny first. There have been reports of the valve body not shifting at the right inflections with synthetic fluids if you don't flush the system well. Again, even if you have metal flakes in your pan, new fluid will reduce the amount. If you can't clean out the pan by removing it, throw a magnet on there to trap it.

[mauricioespana]

Thanks. I will replace the fluid. My mechanic actually used a magnet to get the flakes to settle on the pan so it should solve this problem. Thanks again.