Area Representative nickhi Posted September 16, 2013 Area Representative Share Posted September 16, 2013 I believe I have developed a bit of a Leak from the Gearbox. It's Sigma Roadsport 125 self build. I had noticed a few drops before the 1000 mile service but not really looked too deeply as it was going for the 1000 mile check and guessed they would look into it. A bit of TADTS and I sort of assumed I'd live with it and also seem to recall reading on here that some suffer with this kind of issue without problem. However after getting a litlle annoyed at the mess on the garage floor I thought I'd see how much was leaking. After a 20 mile drive placed a small container underneath and left for 24 hours. The amount is shown here . Having seen how much there was I thought I'd top up the gearbox the other night, it took just about 200ml. Assuming the level was correct at the 1000 mile service (I've assumed so as it's part of the service) I therefore basically seem to have lost 200ml in 400 miles. From memory the gearbox takes 1.2L. I'm probably wrong but this seems to be a little more than a small 'weep' to me. Other problem is I'm not 100% sure where it's coming from. I was under the impression it was from between gearbox and bell housing but I'm not sure how this much oil can get out, pretty sure it's not from the rear as the propshaft, tunnel area and rear of the gearbox seem free of any evidence. It naturally drops from the lowest point as here but there seems to be residue all under the gearbox, I'm assuming this is just how it's getting dispersed whilst driving along. I've got a feeling this is going to be engine out job (and hence expensive) any thoughts or advice? Link to comment Share on other sites More sharing options...
simonpa Posted September 16, 2013 Share Posted September 16, 2013 Hi Nick, did you do the build yourself? TBH - I would not expect Caterham to do much at the 1000mile service other than look at it and check major components were tight - maybe change the oil. I doubt they would check gearbox/diff oil levels. It all looks pretty wet underneath - is that the case? If you can lift the car a bit and get under and feel around the gearbox, you may be able to tell if the leak is from somewhere higher up - i.e. from the top plate. Other than that, I would drive around some more and the see how much top-up is needed - the 200ml you put in may just be the difference between the initial fill and your top-up. Link to comment Share on other sites More sharing options...
Area Representative nickhi Posted September 16, 2013 Author Area Representative Share Posted September 16, 2013 Hi simonpa, Thanks for the reply, yes I built it myself. I had a good feel around the sides and couldn't feel any oil but I'll lift the car and have a nother good look round. I sort of concluded it was from the bell housing mating as after wiping off all the excess after a drive and then feeling around again a few hours later there was definately oil at the bottom of the bell housing to gearbox mating again. I'm going to take the tunnel top cover off, I may be able to have a good look around from the top of the gearbox. Link to comment Share on other sites More sharing options...
RedCat7 Posted September 16, 2013 Share Posted September 16, 2013 Are you sure it isn't engine oil? My Sigma 150 had similar symptoms after a few hundred miles from new. Turned out to be a badly fitted rear crank seal leaking into the bell housing. Link to comment Share on other sites More sharing options...
Supersprint1988 Posted September 16, 2013 Share Posted September 16, 2013 Should be easy to check as gear oil has a really nasty smell. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted September 16, 2013 Member Share Posted September 16, 2013 Is this thread relevant? Jonathan Link to comment Share on other sites More sharing options...
oldbutnotslow Posted September 16, 2013 Share Posted September 16, 2013 OK this is a 5 speed box. Modern hypoid oil doesnt stink to the extent that it used to and this looks too clean to be engine oil but I could be wrong.Its woth having a sniff There is a gasket that fits between the box and the bell housing that is supposed to seal the shaft that sticks through at the top of the box. It is supposed to have an RTV sealant applied to stop it leaking. There is also the possibility that the input shaft seal is leaking. Either way if it were my car I would have the engine out and fix it as this is quite a lot in a small distance / amount of time. One this for sure is that its not going to get better only worse. Link to comment Share on other sites More sharing options...
simonpa Posted September 16, 2013 Share Posted September 16, 2013 If you've already built the car, then removing/replacing the engine shouldn't be expensive at all, should it? Anyhoo - see if you can locate the leak first and take it from there. If you clean it and it leaks (significantly) without running the car, then it's not likely to be the layshaft area. Actually, looking at your picture again, the side and bottom of the main casing looks wet, along with the rear flange and the side webbing, but it looks like it's dry on the underside around the webbing and rear flange. It's definitely not leaking around the top plate or filler/level is it? ISTR there were some gearboxes with leaks between the main case and the tail, but that was a while ago, wasn't it? Cheers - Simon Link to comment Share on other sites More sharing options...
Luegonigel Posted September 16, 2013 Share Posted September 16, 2013 My 150 Sigma with 5 speed box is in Dreadnought garage as we speak for the very same thing. I think I have a leak on the gearbox rear output shaft and a leaking rear crankshaft seal. After an hour and a halfs drive to Dreadnought the leak seems to have blown back from the bell housing/engine joint up the bell housing and along the gearbox. Will revert back by the end of the week hopfully. My car has 15,000 miles on it. Link to comment Share on other sites More sharing options...
Area Representative nickhi Posted September 16, 2013 Author Area Representative Share Posted September 16, 2013 Many thanks for all the advice. Will lift the car up in the morning and have a long inspection and try and identify exactly where it may be coming from. Will clean all round then go for short run then have another look round and hopefully identify where it's leaking out. Simon, will definitely double check the top plate, many thanks. Link to comment Share on other sites More sharing options...
Luegonigel Posted September 22, 2013 Share Posted September 22, 2013 Hi, did you get sorted? Mine is still proving elusive to find so interested in your result. Link to comment Share on other sites More sharing options...
CharlesElliott Posted September 22, 2013 Share Posted September 22, 2013 Three common places: - between gearbox and bell housing, where selector shaft pokes into bell housing recess - speedo drive - top plate Link to comment Share on other sites More sharing options...
Area Representative nickhi Posted September 22, 2013 Author Area Representative Share Posted September 22, 2013 I am still not completely sure but am pretty certain it's from the gear selector rod. I'm guessing that while driving oil is accumulating in the pocket of the bell housing then when parked up it's draining out and finding its way between the bell housing and gearbox. Link to comment Share on other sites More sharing options...
Luegonigel Posted September 23, 2013 Share Posted September 23, 2013 Has anyone got a photo of the gearbox selector shaft area please Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted September 23, 2013 Member Share Posted September 23, 2013 Quoting Jonathan Kay: Is this thread relevant? It has the photos. Jonathan Link to comment Share on other sites More sharing options...
Luegonigel Posted September 23, 2013 Share Posted September 23, 2013 Thanks for that link, a long standing problem then re the selector shaft leak. Photos very helpful in understanding the problem. Gearbox and engine on way out. Link to comment Share on other sites More sharing options...
Luegonigel Posted October 5, 2013 Share Posted October 5, 2013 So, the summary was:- - prop shaft seal leaking which was easy to see - gasket between gearbox and bell housing had a bit missing where the selector shaft is - the cover plate on the drivers side of the gearbox held on with two bolts had silicon on it but not all the way around, probably the main leak. Impossible to see or get at under the car in a normal domestic garage. Incredible how close the gearbox is to the chassis when you look with the benefit of a garage ramp. Flywheel removed to check for crankshaft seal leak, no problem. Garage floor now dry for the first time in ages thanks to Dreadnought Garage in Callander. Surprised to see 4 Caterhams in their place at the same time. Very friendly service in there as always. Any news from Nickhi on his problem? Link to comment Share on other sites More sharing options...
Area Representative nickhi Posted October 5, 2013 Author Area Representative Share Posted October 5, 2013 Reported the leak to CC as I was also having trouble with gear shift into 2nd. I dropped the car in and couple of days later I now have a new gearbox and smooth gear shift and a nice clean garage floor. Great service form CC, really pleased with the result. Link to comment Share on other sites More sharing options...
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