Richfield Posted April 19, 2007 Share Posted April 19, 2007 -what I need to know/discuss etc is the problem of backaxle diff oil leaking onto the brake shoes,there is a felt seal held in place by a spring clip which is supposed to stop this at the outer end of each trumpet , made to seal on the inner hub of the brake drum I am at a loss to see how this really works efficiently I really want to speak(?) with someone who has hands on experience of this problem.I had removed the brake drums so that I could get the linings replaced-and found all soaked in oil! so before doing this need to cure this seal problem-many thanks for your help Paul. Link to comment Share on other sites More sharing options...
jrbartlett Posted April 19, 2007 Share Posted April 19, 2007 You can try replacing the felt seals. It's possible to buy new felt in sheets and cut it to the shape and size needed, or to have a gasket supply company cut it for you. For Cadillacs, someone is probably already making and selling replacements. If you are really lucky, a bearing and seal supplier can often identify and supply a modern replacement seal based on the inside and outside dimensions. Link to comment Share on other sites More sharing options...
Richfield Posted April 19, 2007 Author Share Posted April 19, 2007 Many thanks your reply-yes I will be replacing these seals,the ones that were leaking were not the original in quality or section.I am in the south of France so as you can imagine its not that easy to get the correct info over here!I have been told that the section required is a square section but that does not match the shape of its mounting fixture,is it a strip?,is it cut from a sheet so that it is continous?The questions are many that is why I would like to chat the problem over with someone who has carried out this operation.There is regretabely not enough room for making the modification to a modern type seal unless one was to redesign the whole seal problem-mounting these just outboard of the diff and fitting sealed for life bearings at the outer end-not a task to be taken lightely as it would entail having to machine the inboard end of the trumpets etc etc and of course if there is a problem having to drop and the strip the complete backaxle-so if I can get the correct felt etc I would rather stick with the original method!! Link to comment Share on other sites More sharing options...
jrbartlett Posted April 19, 2007 Share Posted April 19, 2007 I think you need to post this question in the Cadillac-LaSalle and Classic Car Club portions of the AACA forum, and also look up the Cadillac-LaSalle club itself and post on their forum. There are surely a number of people who have encountered the same problem on a Cadillac V-12. I've don't have one of these cars myself. Link to comment Share on other sites More sharing options...
Ivan Saxton Posted April 20, 2007 Share Posted April 20, 2007 You will find that the rear axles of V8, 12, and 16 Cadillacs were essentially the same except for gear ratio and brake drum diameter. In fact there is probably close similarity between that of the 1928 341 V8 and all the twelves and OHV 16's. I am most familiar with 1927 314, which again is similar but with a torque arm instead on a torque tube. I have looked up National Service Manual and found nothing relevant to your problem. That probably means that noone found a problem and it was all self-evident. So you have to look at basics. To start, what lubricates what, and how and how much? First, you lubricate the gearing with oil, which is spread over everything by the crownwheel which picks it up off the bottom of the housing. That means that you dont need a huge amount of oil. The oil has to separate the sliding gear surfaces, be slippery in doing so, and carry away the heat which is generated by the sliding contact of the gears, and the churning of the oil itself as the gears turn in it. Heavy oil generates more heat in this.And the heat signifies loss of power and efficiency. The wisdom and fashion now is rather to use a small quantity of suitably enhanced low viscosity oil.Felt oil seals tend to handle grease well and oil rather badly. The Cadillacs I have between 1913 and 1927 all have felt seals and taper roller bearings packed with grease. I suspect that if your oil level is high because of oil leaks it is quite likely that the leaks are due to the oil level which is kept high because of the leaks. Apart for that there are a few tricks you can try. If the seal track is worn you may be able to build it up with a stainless steel Speedy sleeve. I always use a metal spray coating rebuild for my own stuff, which is much more servicable than the soft stainless sleeve. If you cannot get felt sheet of proper thicness you should cut a stack of rings to the required thickness from the felt you can get from a sewing shop. There is one more trick you can try. Silicone oils do not like to mix with anything else at all. Apparantly you can get them in a range of viscosity, and you should probably try a fairly heavy grade to saturate the new felt seal before the oil or grease gets near it. You may be able to get samples from Dow. And you may make a good business marketing "felt seal primer."This may provote a response from someone who can give better advice than I.Ivan Saxton Link to comment Share on other sites More sharing options...
Johan Boltendal Posted April 20, 2007 Share Posted April 20, 2007 If there is that much oil coming out, two options, the rear axle has been over filled and leaks or has leaked from that , or your leather seals within the differential will be gone,to replace these you will have to take the shafts out, rear cover off and ring out, there you will find them. Replacing the outer felt seals will help for a little while, they will be soaked within a few miles and oil the brake linings again ,Johan Link to comment Share on other sites More sharing options...
Guest Albert Posted April 20, 2007 Share Posted April 20, 2007 I would be checking if there is an inner shaft seal to keep the oil into the pumpkin portion (maybe in the diff portion or right behind the wheel bearing), and the outer felt seal to keep the grease in the wheel bearing... Link to comment Share on other sites More sharing options...
Richfield Posted April 21, 2007 Author Share Posted April 21, 2007 Thank you all for your help and info-what has thrown me slightly off track is the work done by each seal!On a few classic English cars of the 1930's i.e Lagondas /Invictas to name a couple the axle is designed so that a small amount of oil is allowed down the axle tubes to lubricate the hub bearings any excess is funneled away from the braking system and is allowed to run off at the rear of the backplate.From what you are saying is that the oil in the differential is contained by the 2 leather seals and the grease from the bearings by the felt seals-the diff oil is not designed in anyway to help lubricate the hub/brake drum bearings????I imagine that the leather seals have long perished as the car has been immobile for many years in a museum in Switzerland,and the restorer of the car didnt go to the lengths of checking or replacing them.If the above is correct can I at least make a temporary repair by replacing the existing open ball races in the brake drum by a modern replacement 'Sealed for life' bearing??? Then if any oil finds its way down the axle tube(trumpet) it cannot find an escape route through the bearing,through the, at the moment , non existant felt seal and onto the brake shoes !!!Feed back please.(By the way I live in the South of France and earn a living helping to maintain and repair vintage and classic cars in this area-the owner of the Cadillac has also in his stable 1939 4 1/4 litre Bentley,1964(ish)AC Cobra Mk 11,and a 1932 Low Chassis 4 1/2 litre Low Chassis Invicta). Link to comment Share on other sites More sharing options...
Johan Boltendal Posted April 21, 2007 Share Posted April 21, 2007 The above is correct, lower the amount of oil up to 2 cm below the filling point, for the moment, sealed bearings will not be found, I think,besides that, the oil will eventually seep between the housing and support.See to it, that the diff ventilation is open as it should be,it might be clogged with dirt or paint, closed vents will allow the pressure inside to build up and this is the last you want. You will have to repair the failing inner leather seals, when ever you decide to end the leakage.Johan Cad '30 and '32 Link to comment Share on other sites More sharing options...
Richfield Posted April 21, 2007 Author Share Posted April 21, 2007 Thanks Johan will crawl under the back end on monday-to save time can you point me towards the location of the breather hole/pipe/?.Its quite a large chunk of metal and the previous restorer was quite free with his paint brush! Thanks again-Paul.(If you want to sketch out the emplacement my Fax number is 0033 493 91 91 28 and Email is paul.richfield@cegetel.net-not being very literate with computers I have'nt the faintest idea if you can or how to send hand sketches by mail). Link to comment Share on other sites More sharing options...
Richfield Posted April 21, 2007 Author Share Posted April 21, 2007 Johan Sorry mistake crept in there-Email address should read:paul.richfield@cegetel.net Link to comment Share on other sites More sharing options...
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