crawdad

While researching a no-movement-in-any-gear issue with our 2003 Impala 3.4L, I came across TSB 08-07-30-040c from July 25,2012 and it mentions that the old rectangular magnet should be replaced, when possible, with the new! and improved! circular magnets, #29535617. They look like big thick washers and one goes in the usual place while the other sits on a specific area of the filter. Mine didn't have a magnet at all so I'm going to add these but I'm wondering if anyone knows the size?
The one I have from Home Depot is almost 2" in diameter and 1/4" thick but there are other sizes available.
By the way, a total change of the very old fluid with Dexron VI and new filter seems to have fixed the problem for now. I hope it was just a little debris stuck in a solenoid.

crawdad

Update: someone stated on Amazon that the supposed new GM donut magnet is about 1.75" x 5/32". Anyway, not a big deal, just don't want it sitting too high. Probably will get one from RockAuto. Trust them more than ebay & amazon. Someone also said that some magnets lose effectiveness in hot tranny oil.

oilcanhenry

I'd use the stock flat transmission magnet on the bottom of the pan. They catch steel/iron particles fine, Never heard about hot fluid effecting them. Lots of the newer
transmissions dont even have any way to change the filter, as its up in the transmission, and you'd have to dissemble the transmission to get to it. Thankfully, GM has a drain plug on the bottom so you can change the fluid easy, but I'd' say more often too, to get lots of those particles out. The old pans almost never had a drain plug. What a mess that was, unless you had a huge oil drain pan to work with!!!

crawdad

Thanks oilcanhenry. I'm ordering the magnet from rockauto. I think I'll put that on the filter and put the home depot magnet in the usual place. Just curious if any magnet will do. I wish I had a drain plug but since I change the filter too it doesn't matter that much; just less of a mess. I've thought about the fluid extractors but I think it's better, especially for these high-mileage engines/tranmissions for the oil to flow out quickly and take the gunk with it.

oilcanhenry

This magnet might do the trick as long as it doesn't obstruct anything, crawdad:


If you have thirty bucks to spare you can by a Dorman filter pan like this one: https://www.amazon.com/Dorman-265-814-Transmission-Pan/dp/B008J1OVT8/ref=pd_sim_263_6?_encoding=UTF8&pd_rd_i=B008J1OVT8 &pd_rd_r=ES079WBQR2TCQPACRDST&pd_rd_w=SwbDZ&pd_rd_ wg=nSF1o&psc=1&
refRID=ES079WBQR2TCQPACRDST



Frankly I think it would be great on a new vehicle, but Chevrolet and other brands are moving away from replaceable filters and transmission/filter pans are going away, like with my Bu'. You could add a drain plug to your existing oil pan, but they wont drain out all the fluid since they are not flush and you wont be able to clean the magnet or change the filter either.

crawdad

Thanks. I'm getting the magnet from rockauto since I need a few other things like a few extra transmission clips which are only 17 cents each there. And I actually like the idea of changing all the fluid by disconnecting the trans cooler line method and filter as well. But I appreciate the suggestions as I'm learning a lot about transmissions since that total, although temporary, failure left my wife stranded.