| Author | Message | ||
     John Rowney Experienced User Username: johnrowney Post Number: 188 Registered: 02-2015 |
My 1938 Wraith, WXA68, is in trouble again, and I am looking for suggestions which might help me understand what the problem is, and a solution. A couple of weeks ago, I noticed that the left hand rear wheel was leaking oil, which covered the inside of the mudguard and left a large pool of oil on the floor. This occurred suddenly after a short drive. I removed the wheel and the hub. The hub was covered in oil and the brake shoe linings were coated with oil. Luckily the oil hadn't been present for very long. I was able to soak the brake shoes in Shellite for a day, then flamed them after air drying them. I filed chamfers on the linings, and it was clear that the oil had not penetrated, and my soaking and flaming had worked. I then removed the Left Hand axle tube and the oil seal and housing from the differential. The seal still had an internal diameter smaller than the axle and was undamaged. Under normal circumstances no oil could leak in such quantities in such a short time. I found that the end of the axle near under the narrow part of the tube was badly scored as in the photo below.  The corresponding area of the axle tube was also scored badly as in the photo below.  It appears that there may be at least one rivet end missing (see the row of rivets near the bottom of the picture). I have looked at this using my endoscope, but the picture quality is not good enough. I have another endoscope on order, so in a few days I might be able to get a better picture.  My theory is that at some stage the end of a rivet has become dislodged and worked its way into the thin end of the tube and caused the scoring on the axle and the tube. As the piece, or pieces, ground around the space between the axle and the tube, the movement of axle would have been enough to allow oil to pass through the seal on the differential. (Movement of the axle in this manner was suggested by Steve Sparks in one of our many discussions of the problem to be the cause of the leak without the seal being badly damaged). I am soon to remove the axle from the differential housing to see if there is any damage in the differential itself which could have allowed the oil into the tube and eventually into the brake drum. I was lucky, that 9 years ago, Steve had installed grub screws in each of the axle tubes near the differential. After removing the grub screws when I was first aware of a problem, I found that the oil was only leaking on one side of the differential. Eventually I will have to look at the Right Hand side axle and tube to see if a similar situation could exist. If anyone has any thoughts about my problem I would much appreciate them. I am sure that there are other possibilities that I haven't thought of yet. I guess I should expect to encounter these sort of things with the mileage I have been travelling lately. I had done over 8,000 miles in WXA68 in the 12 months prior to this problem. | ||
| Koen Dierckxsens New User Username: prewarrb Post Number: 12 Registered: 04-2024 |
Dear John, First of all: my condolences for what has happened. Secondly, IMHO you and Steve Sparks may be very correct in establishing the cause of the oil leak. If another trivial cause could have existed (hole in tube, oil spill chassis lub or jacking system, whatever,…), I presume you would have noted that – quod non. You have the hardware in your hands - then I will not venture into other reasoning. When heavily accelerating/braking strong torsional forces are exerted on the axle as a whole, pushing the nose (pinion) of your axle up or down. These forces are restrained by brackets over the axles and the springs – you will know all this, I guess. Your rear axle has got two spring suspension brackets (=brackets with a sleeve, one L one R), that have been pushed over your axle tubes and subsequently solidarized both together with rivets (your definition). The rivets are not rivets but “K4849 – taper pin”. This taper pin is ½” long (over all), this taper pin starts with an OD of ¼” and gets smaller following a taper, I quote: “1 in 48 on diameter”. Each chassis would need 56 of these taper pins – 28 on each side. Brackets would have been pushed over axle tubes, then final drilling and reaming (28 holes, just a little smaller than ¼” I guess), followed by pressing (hammering?) taper pins in position. So, in an ideal world, your photograph would have shown 28 lumps. Note, not all rows count 4 taper pins – presumably you will be able to see where taper pins are missing / sheered off? If needed I can help you with position of these pins. Taking into account your full story, I wonder if your suspension brackets are still well solidarized to your axle tubes (no tangential movement should be possible), and your idea about checking the other side makes a lot of sense to me: if tangential movement of spring brackets is at stake, the other side takes full load ? Also: inside differential LH side is very different from RH side (crown wheel). LH side is more prone to oil washing, RH side may keep more dry, but same problem with taper pins may be there? John, you did write the amount of oil spill was considerable. The max oil level is well below bottom of inspection cover and also below the main differential bearing and axle shaft oil seal that is even higher. Yes, It is always possible minimal quantities of oil may pass through this oil seal, but it should be very limited and stay in the bottom of the axle tube, ready to be evacuated when removing your grub screws – I think so. Could it be there was way too much oil in your rear axle? Or your car standing on a side slope? Or... ? Regards, Koen |
