Gavin Posted May 18, 2007 Share Posted May 18, 2007 The gearbox in my vitesse 6 is leaking oil from just about everywhere (inc input and output shafts) - however the gearbox itself works just fine. How feasable / worthwhile is it to replace all the necessary seals and would it be worth it given that from what I've read here the early vitesse gearboxes were n't very strong anyway? Would a reconditioned Mk1 gearbox be a better option? Advice appreciated - thanks Gavin Link to comment Share on other sites More sharing options...
Deleted User Posted May 18, 2007 Share Posted May 18, 2007 Overdrive or no Link to comment Share on other sites More sharing options...
Gavin Posted May 18, 2007 Author Share Posted May 18, 2007 No overdrive .. Link to comment Share on other sites More sharing options...
Deleted User Posted May 18, 2007 Share Posted May 18, 2007 Make sure the breathers not blocked on the selector top (tiny hole in the aluminum towards the front). Also could have been fitted with an overdrive selector top by mistake by previous re conditioner that have this hole blocked from new. If so just pop the little top hat pin thing out. Throwing oil out from everywhere is a sure sign that the box is pressurising. Link to comment Share on other sites More sharing options...
bxbodger Posted May 18, 2007 Share Posted May 18, 2007 I may be being thick here, but how can a gearbox pressurise? Surely it's just rotating cogs and splashing oil, and the actual small volume of air inside can't change much other than by warming up a little, but no way developing enough pressure to physically push oil out of all the seals....or does the air in a gearbox really get hot enough to do that?! Link to comment Share on other sites More sharing options...
heraldcoupe Posted May 18, 2007 Share Posted May 18, 2007 [quote by=bxbodger link=Blah.pl?b=hervit,m=1179473901,s=4 date=1179486639]does the air in a gearbox really get hot enough to do that?! [/quote]Certainly does. Link to comment Share on other sites More sharing options...
bxbodger Posted May 18, 2007 Share Posted May 18, 2007 Me being thick then!! :BI could see it happening in a crankcase because of ring blowby, but I didn't think there was that much void space in a gearbox to contain enough air to cause much of a problem. Link to comment Share on other sites More sharing options...
Deleted User Posted May 18, 2007 Share Posted May 18, 2007 That's why they put breathers on gearbox's, overdrives, and differentials. Link to comment Share on other sites More sharing options...
Jason Posted May 18, 2007 Share Posted May 18, 2007 Next time you come back from a long drive, get under the car and feel the temp of your diff or gearbox - DON'T just slap your hand on it but put your hand carefully close - you will feel the heat. Link to comment Share on other sites More sharing options...
bxbodger Posted May 18, 2007 Share Posted May 18, 2007 But my line of thinking is, that if the air expands and pushes the oil out, on cooling when the car is stopped the air in the box cools and contracts, so for it to happen again the next time you drive the car new air will have to be drawn in to replace the volume of oil displaced through the seals, so for this to happen there must already be enough venting to allow for expansion, unless new air is drawn in through the oil seals, in which case they will be probably knackered.......and it's a slow day at work today..... :) Link to comment Share on other sites More sharing options...
Deleted User Posted May 18, 2007 Share Posted May 18, 2007 Oil tight seals are invariably not gas tight, it's a good thing really.The molecules in a lubricating oil are significantly larger in diameter than any of the gases in air. And if there's enough room for oil to pass out through a seal, then there will be plenty of room for air to get back in. When the gearbox cools the air inside will contract, it will be at a lower pressure than the air outside and the reultant vacuum will draw air in from the outside. It would be almost impossible to make a gearbox casing airtight to prevent any air being drawn in. Indeed if you did then the air inside it would pressurise and try to inflate the casing when it got hot! So the oil blowing by is just that, it's being forced out by the pressure of the hot air. Breathers ensure that the apparatus doesn't get pressurised at all. Link to comment Share on other sites More sharing options...
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