I‘m planing on changing my transmission fluid and filter on my 97 Buick Le sabre. This my first attempt at doing this. The fluid has 106000 miles on it. I have the torque setting for the bolts (13lb/ft). My question is when reinstalling the pan are there any tricks of the trade to insure that I am getting the pan seated right. Or is there any specific staggered pattern for tightening the bolts down to specs to insure that after the job is done I‘m not going have transmission fluid dripping. I just want to get this right the first time. And is there any truth to the myth that after changing the transmission fluid the tranny could start slipping ? Thanks in advance for any help !!
Sometime around that year GM implemented a reusable transmission pan gasket that is far superior in construction to the wadded up piece of crap you will get from the parts store. A lot of people throw away this gasket and use the wimpy one that comes in the filter kit from the parts store and then complain of leaks. My advice if your car is equipped with the thick heavy reusable gasket, look it over clean it and reuse it. If you see any abnormalities in it buy a new one from a GM dealer. Changing fluid in your car is good for it. A BAD TRANSMISSION will often operate better with old ATF in it because it is thicker and can more easily apply clutch packs. When fluid is changed in a BAD TRANSMISSION, it now has thinner oil that blows past the harden clutch piston seals. This is why people think this is the case. Part of making your transmission last involves keeping the fluid changed in it. ATF when new contains additives that protect the rubber seals inside your transmission - over time these additives break down allowing the seals to harden causing internal leaks which in turn cause partial apply of clutches, which leads to clutch pack burn out.
If you're familiar with working on cars etc. you should be able to do this. When tightening the pan bolts stagger the pattern when you snug them. Have all the bolts in and hand snug before torquing them. Now that I've told you that, I will suggest you get a Chilton manual for reference in doing this right and doing it only once. You can check one out at your library. Make sure you get one which covers the specific make and year of your car. I don't believe in the myth that with fresh fluid changed properly any transmission will start to slip.
I don't know of any specific pattern necessary for the pan bolts.However i would recommend that you hand tighten the pan bolts in a random sequence.Then torque them to 13 lb/ft also in a random sequence.I would recommend a light coat of silicon form a gasket on both sides of the pan gasket when you start to go back together with it. I would say that if you are not having problems with the transmission slipping at the present, you won't likely have problems with it slipping after the fluid and filter change.They don't usually start to slip simply because the fluid and filter are changed. When that happens,there was a problem already,before the fluid and filter change.
