When I purchased my wagon almost four years ago, I checked the transmission fluid and found it to be the color of black coffee, so I went out and bought a filter and rubber gasket kit and changed the fluid in the car. Since then the pan and gasket stayed sealed for about a year and a half and at that point started to leak. Now I torqued the pan bolts initially to the factory specified 14 ft lbs and tried re-doing that, but it still seeped. Over the next couple years I periodically "snugged" up the bolts and even went as far as cleaning the outside edge of the pan and slathering silicone around the perimeter of the pan and gasket with limited success, but within the last couple of months, the pan started really leaking from the rear, so I decided it was time to reseal the pan.
I've never liked the cork gaskets and the rubber gasket I used this time didn't seem much better, but I have been reading and hearing about going "gasket-less" this time.
The new generation of silicone has been improved to the point that it really doesn't have to be used in conjunction with gasket material to seal off anything automotive short of fuel related components. Most OEM car manufacturers now use silicone only instead of gaskets because they seal better and for longer periods of time.
I used Permatex Ultra-Grey silicone gasket maker on this project:
The stuff isn't cheap (paid around $15 for the can), but I needed the high torque, high temp (500 degree) stuff because of the heat generated by an automatic transmission.
I also used Permatex High Temp thread sealant as well because you don't really "torque" the pan bolts when you do this , so you need something to seal and somewhat lock the threads as well.
From my research the proper way to do this is put a 1/4" bead of silicone on a totally grease and oil free pan flange, (I actually used two beads), make sure the tranny flange rail is clean and oil free as well. You then put the thread sealant on the bolts, hold the pan up to the tranny flange, install and tighten the bolts only until you feel resistance (do not bottom out the bolts!). The theory is that you want to leave between an 1/8" and 3/16" gap between the pan and the tranny rails for the silicone to seal.
You then let the silicone cure for approximately 24 hours. Then you can "snug up" (but not too tightly) the bolts, then you can go ahead and fill it up with fluid and off you go!
It really sounds on the surface to be more complicated than it ended up actually being, but I know several mechanics who swear by this process to stop leaky gasket problems.
Theoretically, this sounds like it should work (It's been about a week and no leaks so far!), but only time will tell if this is a worthwhile option to a regular tranny pan gasket..
~ Mike ~
How difficult does this make it for removing the pan later to change the fluid and filter?
Wayne Schiff wrote:How difficult does this make it for removing the pan later to change the fluid and filter?
I understand that a little more force is required to break the pan loose, but the pan on a TH125C Cavalier transmission is one thick and stout piece of steel, so it really isn't an issue.
It's worse for your car to run it low on tranny fluid than it is to pry a pan off of the tranny, LOL !!!
~ Mike ~
Sadly they drill a hole out of all the transmission pans at my local Pick N Save to drain them, then put it a cheap plastic plug in it like you would see in the threaded fittings of Brake Calipers. The same with all the fuel Tanks as well. Not much good after that.
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Use windshield Urethane on them, ( available at body shop supply store or windsheid/ glass company) they will never leak. Its messy though if you get it on your hands... let sit for a day and its good to go. Taking it back off is the hard part.
Doug in P.R.
92 Pontiac Sunbird LE, 2.0, AT, Red / Black with Grey 155K miles. Hurricane Maria Survivor ! ( It takes a licking and keeps on ticking ! ).....in Salinas, Puerto Rico!
Next time I buy one of these:
Tranny pan drain plug kit
For as much dirt as your tranny makes, you could windshield eurothane the pan up there forever and change out the fluid with this !
They work as slick as sh*t !
~ Mike ~
Nice details mike.I would like to point out I have been using the permatex high temp thread sealant for almost 20years(I am not joking).This product is 100% sensor safe and can be cleaned off with some brake clean in addition to a cordless drill brush for the cleany factor.The short boring story is I learned of this product working for Thomas built buses and that is learn factor of this superior product.I will say the ultra grey is great but,yeah the removal process of a part applied too is kind of tough.I personally prefer permatex (The right stuff) sold for about 14.00 and cures super fast and will seal and not leak just as well.The right stuff cures out in 24hrs totally as well,but sets ups quick and fluids can be added in a hour with no problem.I used this on my oil pan as the 1.8 and 2.0 are notorious for leaking at the trans end and crank.Thanks for the details and I am just wiped out tonight and done with loads more of thoughts.Great INFO and sharing this just broadens our members with very GOOD advice!!!!Trucking just kick'd my rear today.
Hey, I really like that plug kit Mike! Maybe all those drilled out pans aren't so useless at the yard after all!!
Only bad thing I could see is make sure you would have proper internal clearance at the point you choose to use this before drilling your hole. Kinda make for a really bad day if you were to bolt your pan back up and discover that the nut inside the pan contacted the filter or something and wouldn't let the pan seat.
Got a country bumpkin idea to check that though. Place a magnet on the outside bottom of the pan where you want to drill and put that nut inside - the magnet ought to hold it right where you want to drill while you test fit the pan in place to see if there is the clearance you need.
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~ Mike ~ wrote:Wayne Schiff wrote:How difficult does this make it for removing the pan later to change the fluid and filter?
I understand that a little more force is required to break the pan loose, but the pan on a TH125C Cavalier transmission is one thick and stout piece of steel, so it really isn't an issue.
It's worse for your car to run it low on tranny fluid than it is to pry a pan off of the tranny, LOL !!!
I'm thinking it's so much worse for your car to never be able to drop the pan to change the filter.
Wayne Schiff wrote:~ Mike ~ wrote:Wayne Schiff wrote:How difficult does this make it for removing the pan later to change the fluid and filter?
I understand that a little more force is required to break the pan loose, but the pan on a TH125C Cavalier transmission is one thick and stout piece of steel, so it really isn't an issue.
It's worse for your car to run it low on tranny fluid than it is to pry a pan off of the tranny, LOL !!!
I'm thinking it's so much worse for your car to never be able to drop the pan to change the filter.
Wayne, it's silicone. not Gorilla Glue !
The product is designed to be removed - maybe not as easily as a squeezed-out rubber or cork gasket, but certainly better than windshield urethane as was suggested earlier. It is designed to replace the gasket, not to bond permanently...
If you are afraid of it, don't do it. Just trying to impart the wisdom that I have acquired from decades of wrenching and a boatload of companions that do the same...
~ Mike ~
Been following this thread and this stuff looks pretty cool. Great thing is it can be any gasket needed in a pinch and you don't have to trace out and cut like a roll gasket.
84conv wrote:Been following this thread and this stuff looks pretty cool. Great thing is it can be any gasket needed in a pinch and you don't have to trace out and cut like a roll gasket.
You are correct !
I have several friends that wrench for a living and to the man - all claim that because of new strain of performance silicone gasket makers, it really is no longer necessary to use gaskets anymore !
~ Mike ~
