This year I have enough with trans fluid leaks… a drop here a drop there and then it turns into a an ugly mess, what a pain!
Yoke is undergo (Trying to fix FMX leak atr the pan | Mercury Cougar Owners), so here is the gasket/pan “story”: a new gasket was installed last year (by expert mechanic) and lasted for about 4 weeks before leaking one drop at a time and then few drops bla bla bla.
The pan has been stretched a few times I guess and is now not 100% flat anymore, especially around the bolting holes. Glue and/or gasket maker that was used did not succeed so I am not going this route anymore. I believe the problem is that the pan is too soft + the gasket is too tin & not compressible enough so the first thing most people do is tightening up, which makes things worse. This design coupled with the ultra-low tightening spec (10-11 lbs.) was probably OK to get these cars out the show room but time has proven this was not appropriate.
So here the plan: 1/8" aluminum inserts on the whole perimeter of the pan (to reinforce) with a soft easily compressible 1/8" thick urethane gasket (that I molded myself from the pan). I will torque enough to make sure the gasket marries with both the pan and bottom of tranny. I would have wished the bolts to be just a little longer and not sure how the gasket will age with thermal cycling of the trans fluid… w’ll see.
Are you sure your shift shaft seal, modulator gasket or any other point higher than the pan isn’t leaking and accumulating around the pan rail? I haven’t had a problem with FMX pans leaking use a cork gasket clean and dry. If it is only your pan leaking, stiffening the rails and using that mega gasket should help.
Well it sure leaked up there at some point in time as there still are traces of these leaks… and I had to debate with myself whether or not these were still active, but after wraging more than once without oil coming on the wrag, I decided to get a new gasket installed last year by an expert and it was OK for few weeks so it sure does not come from above.
Here is what I did: first worked again on the pan trying to make it perfectly flat… came OK on the longer sides but still was a tiny filet of light coming through on the shorter ones, between the holes… but hey that was the very best I could do. Then re-installed with the thick gasket and torqued just enough to squeeze it firmly in place and get what seemed to be a good full contact all along the edges between the pan and the bottom of casing. The aluminum reinforcement on the perimeter of the pan truly helped me not to over torque as I could feel the distribution of the force on the whole surface while I was screwing, I could see the whole gasket being compressed uniformly all at once.
Filled with trans fluid until it exited through yoke (which is still under repair) and there was no leak after a few hours… I keep finger crossed till tomorrow… then each time I will be driving the car thereafter, hoping gasket does not age too quickly with thermal cycling.
Update to testing: car is actually in storage so I can’t take it out for true road tests but there were no leaks at the pan level nor through yoke (see http://www.mercurycougar.net/forums/...ough-slip-yoke) after a few loops in close neibourghood yesterday and a few “idling till warm” sessions today… so how long these repairs will last is yet to be seen, but at least the first steps are completed with success!
Keep in mind that you lose points in concours judging if you don’t have some red spots under your car. I suppose you could bring a small jar of type F to shows. Same goes for power steering. Need a bigger jar for that. Good job on the pan.
OK whole you, time for update on this…
The thick gasket stood up well for the whole 2016 summer (±6,000 miles) before leaking again in 2017. Not sure though if it was related or not with a broken trans mount that needed to be changed last summer (https://cccforum.discoursehosting.net/t/new-noise-in-transmission-when-put-in-gear/7888/4) … So I thoroughly tested this winter to find out that leaks occur: #1) through pan gasket in the rear passenger side corner (mounting bolts are kind of far from this corner); #2) at the joint line between bottom of the bell and the trans box (that may have been stressed a little while changing the trans mount last year).
Since #2 is not severe (only a few drops per day), I decided to attempt sealing it with Permatex grey silicone gasket maker… and while being there with an opened tube of the gasket maker, I decided to use the remainder to make a new gasket, hoping that it will work for me as well as it for Legendarylimeaz! Fluid is going back in there Saturday morning… I’ll keep fingers crossed.
Silicone has replaced gaskets from some manufacturers. If the surfaces were clean and dry it should work with no problems. The leak between the bell and trans could be either a front seal or pump o-ring. Both of which require the trans to be removed.
Working as a diesel tech for many many years this was all that was used when it came to sealing up leaks or rubber gasket t-joint intersections etc. with a diesel nothing short of this stuff would work. I have used it for just about everything in the past with great success. I had an 86 toyota hilux turned rock crawler and the transmission and t-case would constantly leak since they had about 6 paper style gaskets holding everything together. got sick of it puking on the garage floor so used the grey silicone and never had it leak again!
Well I guess concours judges will have the rise their standards as Permatex seems to be on its way to withstand its promises… still no leaks 2 days after filling the trans fluid. Tomorrow I will be idling the car till warm, then repeat a few times in the next few days, before lowering it down the candles for “extended testing” i.e. riding it repeatedly 3-4 feet back and forth in the garage (winter tires are required by law here in this season and obviously my Cat is for no reason going to wear those!).
I guess that is it (front seal). It started to leak (1-2 drops per day) a few days after I installed the new silicone gasket, however not around the pan hence gasket is fine. Drops of oil form at bottom of the bell while surface of the bell is dry. I am considering adding AT-205 to gain some time before I get it fixed properly.
AT-205? Haven’t heard of it. Don’t add any stop leak to your trans unless you’d like to be rebuilding the trans in the not to distant future. The stop leak not only softens the seal that is leaking, it softens every seal and sometimes to the point that the rubber disintegrates. Which of course creates bigger problems.
Thanks Todd for your confirmation that this stuff can work well in FMX.
Mark: it would appear that new FMX pan is not available, no repro… so I figured that if I end up having to fix a used pan, why not fix mine hey hey
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