jps Posted July 23, 2015 Share Posted July 23, 2015 I have a leak near the rear passenger-side wheel and am pretty sure it is differential fluid. There is a spot on the floor immediately under the "port" shown in the middle of the attached photo (you can see a bead of fluid just about to fall). Some fluid may also be travelling down along the axle to the differential pumpkin, and a spot occurs on the floor there as well. I am pretty sure the pumpkin is fine - no loose bolts and no signs of a leak there. i don't know the purpose of the "port" as shown in the photo, but I assume there is some kind of seal somewhere that has broken. Does anyone have info on how to fix this and what might be wrong, and what the seal material is? I don't know anything about the differential except how to add more fluid. Thanks. John Link to comment Share on other sites More sharing options...
AzBob Posted July 23, 2015 Share Posted July 23, 2015 John, I have similar leakage on my 1926 differential. From my understanding, the purpose of the "port" is to divert oil down and away from the brakes. At some point, this safeguard fails as both of my rear brakes are covered in oil. Apparently, the seals are felt. In addition, I believe some of the rivets are leaking on mine as well. Hopefully, someone will chime in who has been down this road. Link to comment Share on other sites More sharing options...
ROD W Posted July 23, 2015 Share Posted July 23, 2015 John, These tubes are called rear axle drain tubes, function is to drain surplus oil from the axle tubes, thus preventing its accumulation on the brakes, This is per my Motor Car Operation and Care Manual. The standard Buicks and I assume the smaller 29 Buicks have a 3/4 floating axle, compared to a full floating axle on the larger series cars. So the rear wheel is attached to the axle. To replace the felt seal you need to remove the wheel using a puller Link to comment Share on other sites More sharing options...
michaelod Posted July 23, 2015 Share Posted July 23, 2015 As I understand it the problem originates when oil that is too thin a viscosity is used in the differential, thus working its way past the seals. In the Ford Model A crowd, 600W oil is the recommended solution: http://www.snydersantiqueauto.com/600-w-oil Link to comment Share on other sites More sharing options...
jps Posted July 23, 2015 Author Share Posted July 23, 2015 Thanks everyone for the help - especially michaelod ...your answer makes sense as I substituted the highest viscosity gear oil I could find at the local stores, which is 85w-140. So I will try the right stuff now that I know where to get it and I bet you are correct that it will solve the issue. Actually I think Little Dearborn in Miineapolis/St. Paul also may also carry 600W oil so I will go there on Saturday. Thanks again everyone - it really helps to get this feedback. john Link to comment Share on other sites More sharing options...
nickelroadster Posted July 24, 2015 Share Posted July 24, 2015 It may just be that your seals are worn out. Most likely the car has felt seals. Try Olcar bearings and seals in North Carolina. He can pretty much cut any size tha tyou need. Link to comment Share on other sites More sharing options...
Bill - 29 Buick Posted July 24, 2015 Share Posted July 24, 2015 John: The 1929 Buick Canadian Reference Manual calls for A200 lubricant in the diff. When I first got my roadster, I contacted Esso Canada and their Tech. people checked with GM Canada re their orig. specifications and recommended an Esso/Exxon Spartan EP680 which I've been using. It's only available here in 5 gal. pails. Bill McLaughlin1929 McLaughlin Buick RoadsterSupporter of "All Together Parking by Era" Link to comment Share on other sites More sharing options...
Mark Shaw Posted July 24, 2015 Share Posted July 24, 2015 A200 lube details are here: http://www.idealvac.com/files/brochures/A200_MSDS.pdf It is interesting to see that the original specified oil has a viscosity of 58 CST (Centistokes) at 30 degrees C. The conversion chart at the link below indicates 58 CST is about equivalent to SAE 90wt gear oil at 40 degrees C (adjusting for temperature difference).http://www.doolittleoil.com/faq/viscosity-sae-iso-or-agma I use Shell Dentax or Texaco Thuban SAE 250wt in the transmissions and rear ends of all my teens and 20s cars. The high viscosity helps slow the gears between shifts to speed up shifting and it tends not to leak much. Link to comment Share on other sites More sharing options...
Rooster Posted July 31, 2015 Share Posted July 31, 2015 (edited) If you feel motivated, this is what I did to mine to solve the problem. When I was building the car I could foresee this was going to be a problem. So I put the axle in a lathe and machined the area where the felt seal runs. You only need to take off a small amount of metal. Then retrofitted a neoprene lip seal into the housing and the result no leaks at all.I also took the complete diff housing apart by removing the rivets one by one and threading the hole to take a mushroom allen socket head bolt. Smeared the housing faces with Loctite and rebuilt it all with new bolts not rivets ( with nyloc nuts and loctite on the threads )22 years on and no leaks. By the way --- Hello Bill Edited July 31, 2015 by Rooster (see edit history) Link to comment Share on other sites More sharing options...
AzBob Posted July 31, 2015 Share Posted July 31, 2015 (edited) If you feel motivated, this is what I did to mine to solve the problem. When I was building the car I could foresee this was going to be a problem. So I put the axle in a lathe and machined the area where the felt seal runs. You only need to take off a small amount of metal. Then retrofitted a neoprene lip seal into the housing and the result no leaks at all.I also took the complete diff housing apart by removing the rivets one by one and threading the hole to take a mushroom allen socket head bolt. Smeared the housing faces with Loctite and rebuilt it all with new bolts not rivets ( with nyloc nuts and loctite on the threads )22 years on and no leaks. Rooster, I am considering doing the same to the rear axle on my '26-26. The rivets appear to be leaking and your approach looks like the way to go. Did you use 1/4 - 28 button head socket screws? Please post pictures if you get a chance. Thanks Edited July 31, 2015 by AzBob (see edit history) Link to comment Share on other sites More sharing options...
jps Posted August 2, 2015 Author Share Posted August 2, 2015 OK, so I would like to try higher viscosity oil first, and if that doesn't help much, then look at the seals. However, if I check the seals I don't know what I am looking for - I know I have to take the wheel off first (with a puller) but once that is done will it be obvious where the seals are located? And does anyone have dimensions for the rear felt seals such that I could make/buy new ones to replace them before the wheel comes off (before I see them for the first time)? Thanks. Link to comment Share on other sites More sharing options...
Rooster Posted August 3, 2015 Share Posted August 3, 2015 To replace the rivets I ground off the head of one rivet. Punched it inward and tapped it out 3/8". As I recall I think the original rivet was 5/16" ?If it was 1/4" then tap out 5/16"Then screw in a button head. I did this one by one both sides of the centre housing. Doing it this way makes sure that it all goes back together easily.Then take all the screws out, separate the axle tubes from the centre. Clean it all up and then I used a Loctite product smeared on the inner faces and began to replace the button head screws one by one. Put Loctite thread sealer on the screw threads and tighten and use a nyloc nut on the inside. I can't remember the length of the screw but it only needs enough thread to go into the nylon of the nut.Axle housing now nice and tight with no leaks.Obviously the differential needs to completely dismantled for this procedure.I took some photos, but since the website upgrade I don't know how to add then now. Link to comment Share on other sites More sharing options...
Mark Shaw Posted August 3, 2015 Share Posted August 3, 2015 Jps, Try calling Olsen's Gaskets. http://www.olsonsgaskets.com/ Link to comment Share on other sites More sharing options...
AzBob Posted August 3, 2015 Share Posted August 3, 2015 jps in addition to calling Olsen's Gaskets, I just checked Bob's Automobilia volume #61and has listed 1929 &'30 Rear Wheel Seals on page 48. Rooster, I had no idea there was enough room on the inside of the rear axle housing to accommodate Nyloc nuts. Thanks for the info. Link to comment Share on other sites More sharing options...
Bill - 29 Buick Posted August 5, 2015 Share Posted August 5, 2015 Thanks Ken. Link to comment Share on other sites More sharing options...
jps Posted August 5, 2015 Author Share Posted August 5, 2015 Thanks Bob for the suggestion to check out Bob's. I did contact Olsen's Gaskets and Francis there said that he could cut felt gaskets to my dimensions, but he didn't know the specific dimensions needed for a '29 standard. So he referred me to Tony Bult (he is well known for restoring '29 Masters) but I think Bob's should be fine. It seems like I always have a list of stuff to buy from Bob's anyway, so I will just place an order to include new rear seals. My car seems to be running much better now since replacing the heat riser tube, cleaning the carb, and getting a new battery. If I can get the rear leak fixed or at least reduced, I should be able to go back to the list of things I wanted to do to improve the car rather than just fix things that break Link to comment Share on other sites More sharing options...
DonMicheletti Posted August 5, 2015 Share Posted August 5, 2015 If the rivets are not loose you can do what is called " caulking". That is where you get a round nose punch and pein, using the punch and hammer, the area of the leak. It is surprisingly effective. It will also work at the joint where the axle tubes meet the center housing.You would pein the edge of the head rivet where it meets the holding surface. This method is commonly used on riveted steam boilers to seal small leaks. Link to comment Share on other sites More sharing options...
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