Looking for a good solution to get my turbo 400 pan to stop leaking. 2 weeks ago I decided I was going to have a leak free transmission on my 72 for the first time in my adult life! (Bought this car when I was 18, I am 44 now!). I fixed small leaks on the speedo housing, electric SP/kick down connection, and shifter shaft seal successfully! I had previously fixed my vacuum modulator. Only thing left was the pan gasket......... I have the summit racing aluminum pan http://www.summitracing.com/parts/sum-433884. I have verified the pan is flat/square. I have tried the original rubber gasket the pan came with, the Fel pro composit gasket, and the $30 Moroso metal core gasket unsuccessfully........I even tried using ATF resistant black sealant with the Moroso gasket.....still leaked! Truthfully the original rubber gasket worked the best. I have only made it worse with each attempt to fix! This last time I even broke out the torque wrench and torqued to all bolts to 10 lbs to make sure it wasn't flex.....no luck. I always leaks in the driver front corner of the pan....constant slow leak....but will drip a 6 inch circle of fluid overnight. I have quadruple checked above the pan....everything is dry...the leak is definitely coming from the pan at that corner. I also checked very closely for a crack in the housing....all looks good. I am out of ideas. Anyone have a highly recommended sealer or method to stop this pan leak?? I am out of ideas.
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. I remember reading something about a corner of the th400 transmission needing a shim to correct this. And,as it turns out,I misremembered..." Pontiac Technical Bulletin 70-T-15,dated 5-28-70 reported a fix for the problem of oil leaking from the rear area of the oil pan on all 1965-1970 engines. Oil pan replacement package (484083)should be installed...". Pontiac GTO Restoration Guide,Paul Zazarine & Chuck Roberts. An automatic transmission fix would have transferred across some sister GM divisions,but not engine fixes. Oh well. Good luck w/this!
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. I have that same pan on my Riviera for no other reason that the factory pan rail was so bent up. Personally, I prefer the old school thick cork gasket. I think there is more 'give" with the cork to compensate for any irregularities. That being said, are you sure the pan isn't tweaked or has a dip in the casting in that area? Have you tried putting it on a granite Counter top or a piece of glass to check it for a wobble? Is the pan porous possibly? When it does leak, is it wet at the gasket itself only or is it wet slightly above the gasket? Oil leaks down
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. I checked it on a flat table. It laid flat. When it leaks it seeps right at the gasket. Seems to come from between the trans and the gasket, then leaks down the pan from there. Maybe I will try a cork gasket. Only have tried the rubber and composit so far.
Help me with my quest to have a leak free turbo 400....can't get the pan to stop. If everything is flat, it ought to hold. Could there be a crack in the case? When all else fails glue that pan back on. That even fixes the chain cover of a TH425. Bruce Roe
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. x2 use rtv black with nothing else and circle every hole never failed yet
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. Im pretty sure RTV black is oil soluble. If anything, Eric could use the gray non hardening RTV paste that can withstand transmission fluid. Normally, a transmission gasket shouldn't need any sealer
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. Is if a deep pan and does the filter have a metal tube connecting it to the pump . If so pan may be snugging up against the corner of filter, u only need one O ring on tube at pump , 2 may drop it too far. Thick rubber cork gasget, or the black one never used anything else , silicon is never used with gasget on tranny. , will end up in filter if u over do it. If none of the above aplys try locktite weld on the corner of case , just a thin skin on the corner of gasget surface of trany
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. Have you ever tried Permatex 'The Right Stuff' ? I have had success using it on pesky leaky pans and it seems not to be affected by most any type of tranny fluid.
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. I will try this if the new thick cork gasket fails. Thx.
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. You still have one idear you haven't tried, a stock pan. An extreme trial would be a nother case . You would be major hardcore if you did that. Your street cred would be through the roof with that. One draw back of an aluminum pan is there is no flex. , won't conform to any unevenness .
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. Cork gasket with RTV on the pan side seems to have fixed it for now. :TU:
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. Sigh. Leaking again now after driving it a few times. Same place at drivers front corner of pan, but also a small leak on passenger front corner also........, but at least the leak is small this time. I will try to fing some time this weekend to pull it down again. At this point I am suspecting the aluminum pan (although I have no idea how it would leak). I think I will go back to the stock pan with the Moroso silicon gasket and see if that works.
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. Are you sure you don't have a hairline crack in that case somewhere on the rail?
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. maybe someone here will tell me this is wrong but my teacher always taught us to use yellow snot on the pan then a rubber/cork gasket with axle grease on the transmission side light coat. I don't have any leaks there but? Just the way I have always done these and valve covers/oil pan. rear main is another story Still dry as of now:beer
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. I have experienced some of the aluminum china pans are porous. Had to clean & bake the pan in an oven at 450* for a couple hrs. Clean again with Brakleen after it cools & bake again. No more oil residue should be present. If it is clean & bake again until there is NO more oil residue. Then completely coat the inside with an epoxy sealer that hardens.
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. X2...had a horrible time with the pan gasket on my BBC...much like your story, first tried rubber, then cork then stripped everything and used The Right Stuff and leak free 4 mos now. I learned 2 things about it. The only thing special about TRS is you can put the vehicle back into service immiediately. Other than that it is just like the Permatex Ultra Black which is oil resistant. I you go looking for TRS at your parts store, check it because not alot of peeps know about it and it has usually been on the shelf for a while. I found numerous ones that were 'fully cured" on the shelf. They guarantee it to outperform any conventional gasket and what is good about it is that it is going going to conform and seal any irregularity you may not be seeing. Like Buford said, it's great on troublesome sealing apps. I have used it also on my BBB too. Ditch any gasket, clean it real good after scraping and then run a bead on the pan around the bolt holes and set it up. Keep in mind the directions on TRS say that you only have about 10 minutes open time. I'd be shocked if it still leaked and if it does something is warped lol. If you are methodical about the bead you won't have to worry about any getting into your Trans filter. BTW, isn't RTV oil soluble...might be why your last attempt failed after use...
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. Thanks, I will try this next instead. I actually just used TRS for the first time last week when fixing a leaky rear seal on my manifold. I was very impressed with it. Once dry, noticeable difference between TRS and what I had previously used (ultra black). TRS feel is closer to a rubber gasket and adhesion to metal was excellent. Thx.
Re: Help me with my quest to have a leak free turbo 400....can't get the pan to stop. My summit pan had a hair line BARELY visible crack at the left front corner. Those pans are terrible quality, I learned my.lesson
