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Gearbox seems to be leaking

Discussion in 'Mondial' started by 88MONDIAL, May 5, 2020.

  1. 88MONDIAL

    88MONDIAL Formula 3

    Apr 13, 2005
    1,017
    Racine, Wisconsin
    Full Name:
    Jim Smith
    I was changing my oil and noticed that almost 3/4's of the gearbox gasket is leaking, most of the bolts holding it on (like 11 of the 14 or so) have oil hanging off them and the gasket area most of the way around is wet. I had my guy put in Redline (which REALLY helped with second gear!). I just feel uncomfortable as it's not just a tiny leak I believe. Anyone experience similar problem?
     
  2. moysiuan

    moysiuan Formula 3
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    Nov 1, 2005
    1,826
    Toronto, Canada
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    Andy
    Pretty common. A new gasket is the solution, taking off and replacing the gear box cover is simple (although there is the three balls and springs and a spacer that need to not be lost flinging away when the pan is removed, and you must note the order of how they sit in their holes to reassemble them correctly). There are some threads on this if you want to tackle it.

    You could just snug up the nuts a bit, but with caution, the torque is not very high on the nuts and the studs can be stripped easily. Many overtighten to reduce a leak, and end up with stripped studs. Use a 1/4 inch ratchet with the 10mm socket, and have your hand over the socket area so you can not apply much torque. The difference bewteen too loose and leaks, just right, and stripping the stud is a very fine line.

    Many people also use a nyloc nut in place of the factory nut, which can prevent some of the oil weep around the stud. I use a bit of hylomar on the nut washer and stud threads to deal with the potential weeping although with a new gasket there would be no weeping. No leaks on mine since, with Redline like you have.

    No sealer on the new gasket, otherwise is a problem to remove for later service. You can get the metric nuts anywhere, but Bel Metric has a good selection.

    You should also know that the oil could be coming from elsewhere, and only looks like it is on the oil pan. I would first get a rag and clean things up first, snug up the nuts and then check after a bit of a drive to see if the source of the leak if it still leaks is clear. The oil pan could be leaking, the shift shaft seal at the engine front, the camshaft seals/cam cover area once you drive oil can move around everywhere and ends up dripping off the pans as the default path for a drip to take.

    But it is just as likely a new pan gasket is due.
     
  3. mike32

    mike32 F1 Rookie

    May 13, 2016
    2,604
    Uk
    Like the other reply you have- if you let off the bolts and drop the pan you will end up with springs and bits falling out and mixed up- be sure u get it on a ramp and remove the cover slowly with another set of hands.
     
  4. 88MONDIAL

    88MONDIAL Formula 3

    Apr 13, 2005
    1,017
    Racine, Wisconsin
    Full Name:
    Jim Smith
    Thanks for the information guys! I won't be doing this myself. I just had this all done with my major in Oct-Nov. 2018, so this gasket and oil is all fairly new. Just the fact that most of the studs and most of the way around the gasket is wet is leading me to believe it's probably that but I hear what you're saying where it could be coming elsewhere. I just don't want too much to leak out (since you can't really tell) and have my gearbox run below minimum. Maybe it would take many years for that to happen. It's not easy for me to get my car in.
     
    sonfield likes this.
  5. greatscott73

    greatscott73 Karting

    Sep 1, 2017
    177
    West central Florida
    Full Name:
    Howard Scott
    If it makes you feel any better, I never had a drop out of the transaxle on my 87 until I switched to redline, and it started dripping off the studs almost immediately afterward. Pick your poison, I guess: drips or a fully functioning second gear, lol.
     
  6. 88MONDIAL

    88MONDIAL Formula 3

    Apr 13, 2005
    1,017
    Racine, Wisconsin
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    Jim Smith
    Ha, that's funny! I just don't want too much to come out. Maybe once a year I can undo that plug in the back of the pan about 2.5" up, I think that's the fill hole and stick my finger in there to assure that it's near the bottom of the hole or something.

    I'll stick with Redline and the leak! :)
     
  7. greatscott73

    greatscott73 Karting

    Sep 1, 2017
    177
    West central Florida
    Full Name:
    Howard Scott
    You and me both!
     
  8. yelcab

    yelcab F1 Veteran
    Consultant

    Nov 29, 2001
    9,829
    San Carlos, CA
    Full Name:
    Mitchell Le
    Unless it is leaving a puddle on the floor, living with a minor weep is the way of Ferrari.
     
    paulchua likes this.
  9. davem

    davem F1 Veteran
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    Jan 21, 2002
    5,903
    Stepford, Connecticut
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    dave m
    If mine stops leaking i'm worried its empty!
     
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  10. moysiuan

    moysiuan Formula 3
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    Nov 1, 2005
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    Toronto, Canada
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    Andy
    Fyi, I have redline, a new pan gasket and no leaks. I get that some small leaks are acceptable to many, but it is not by design that there are leaks, a nearly leak free car is quite possible.

    I would suggest at the least you just get a 10mm socket or wrench and snug the nuts up a bit. The dry gasket needs just the right amount of torque to prevent the leakage, about 5 ft pounds is all it takes (60 inch pounds). Your mechanic might simply have used very low torque to avoid stripping, but may have been too conservative. The nuts are not nyloc types, and can loosen with all the heat expansion contraction, I am surprised the factory used no lock washer, just a plain flat washer, and not the nyloc style nuts which were used by the factory in all sorts of other places. Replacing with nyloc nuts, with proper torque, would be a good easy do it yourself project.

    Since you are prepared to look under the car and inspect the drips, it is not much more work while under there to replace the nuts with nylocs, torque carefully and probably solve for the weeps, or of course have your mechanic on a lift look after it in a similar fashion. To be sophisticated about not overtightening, you can get this small torque wrench if you are not comfortable doing it by feel.

    https://www.amazon.ca/TEKTON-24320-4-Inch-Torque-2-26-22-6/dp/B00C5ZL2EG

    The Bel metric M6 nuts are here...they look nice in zinc yellow, the plain silver zinc are aslo available at 1/3 the price. Bel Metric supplies small order quantities, hence why it is a popular supplier for small projects and a good source for hoses and other bits on our Ferrari's.

    https://www.belmetric.com/coarse-c-3_752_753_863/nn6ylw-nylon-lock-nut-yellow-zinc-p-156.html

    In any event, just noting all this in case others search for this common leak area and come accross this thread.
     
  11. 88MONDIAL

    88MONDIAL Formula 3

    Apr 13, 2005
    1,017
    Racine, Wisconsin
    Full Name:
    Jim Smith
    Appreciate the posts guys, thanks! I took it for a 20 mile spin out in the country, had several drops hit the cardboard, like 5. I shined my flashlight, it almost looks like it is wet coming from the plug on the back end, the one you fill from. I'll have to make sure that is snug too!
     
  12. greatscott73

    greatscott73 Karting

    Sep 1, 2017
    177
    West central Florida
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    Howard Scott
    Sometimes the crush washers on those plugs don’t get replaced, and they will leak if used more than once. Don’t ask how I know...
     
  13. 88MONDIAL

    88MONDIAL Formula 3

    Apr 13, 2005
    1,017
    Racine, Wisconsin
    Full Name:
    Jim Smith
    Good point! Would you happen to know if the crush washer is the same size as the oil drain crush washer? I didn't get it on ramps, but tried crawling under it and it is the same size hex as I was able to just get it in there to make sure.
     
  14. moysiuan

    moysiuan Formula 3
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    Nov 1, 2005
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    Toronto, Canada
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    Andy
    #14 moysiuan, May 10, 2020
    Last edited: May 10, 2020
    The gearbox fill and drain plugs are size M22 with a 1.5 thread pitch. So you need a 22mm copper washer. The engine oil drain plug is not the same size.

    https://www.belmetric.com/solid-washers-c-4_2121_2123/gsc22x27-solid-copper-gasket-p-525.html?zenid=qhbr8tl4pc0fadvnktecjvnua5

    That said, I never find the copper washers seal well without torque that seems to be on the margin of stripping threads. There are plenty of threads about stripped hools for the various plugs.

    Anyone use a better type of washer that seals more reliably and less rsik of bodging things up? There are the cardboard types on many modern cars, some have hollow copper crush washers, others use aluminum washers, some steel or aluminim with rubberized sealing surfaces. This one looks good to me, but I have not tried it. https://www.belmetric.com/hollow-crush-washers-c-4_2121_2124/gca22x27-copper-hollow-crush-gasket-p-6156.html?zenid=qhbr8tl4pc0fadvnktecjvnua5
     
  15. greatscott73

    greatscott73 Karting

    Sep 1, 2017
    177
    West central Florida
    Full Name:
    Howard Scott
    You didn't really think they would use the same size washer on all the plugs just to make your life easier, did you, lol? I bought a copper crush washer assortment kit awhile back for about the same price as one or two factory washers, and it has served me well. As mentioned, the factory torque on these things seems to approach nerve racking values. I started torquing mine by "feel" and so far nothing has stripped, and nothing has leaked from those sources.
    I spent an hour or so of a rainy Sunday under mine yesterday snugging up all of the 10mm nuts to see if it would help any fluid drip there. I shall report back once I get the car on the road. It has been mentioned by others in the past that sometimes the studs themselves have to be replaced to solve this issue, for what reason I have no idea. That will be performed when I eventually do the pan gasket. The nyloc nuts are also a great suggestion.
     

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