Mars Posted March 16, 2018 Share Posted March 16, 2018 1930 desoto cf .any ideas on how to stop dripping gear oil? Link to comment Share on other sites More sharing options...
keiser31 Posted March 16, 2018 Share Posted March 16, 2018 (edited) New gasket? Do NOT over tighten the cover bolts or they will strip. Edited March 16, 2018 by keiser31 (see edit history) Link to comment Share on other sites More sharing options...
C Carl Posted March 17, 2018 Share Posted March 17, 2018 What weight oil , how much does it drip , and precisely from where ? - Carl Link to comment Share on other sites More sharing options...
JACK M Posted March 17, 2018 Share Posted March 17, 2018 Not uncommon for leaks at the pinion seal. Take the drive line off, then the yoke, drill a small hole in the seal and put a screw in the hole pry out like you are pulling a nail. Be sure to tighten the yoke up pretty tight when putting back together. Top off the lube. Link to comment Share on other sites More sharing options...
Spinneyhill Posted March 17, 2018 Share Posted March 17, 2018 (edited) All the differential carrier and cover bolts have one end in the air and one in the oil. The oil works its way up the threads. it is hard to stop it. There are thread seal products available. The threads must be spotlessly clean before you put it on. The rear cover may be warped by over tightening. It is pressed steel with a cork gasket. If the gasket is squashed at the bolts, the cover warps. Remove, flatten cover flange, refit with new gasket and sealer. Edited March 17, 2018 by Spinneyhill (see edit history) Link to comment Share on other sites More sharing options...
keiser31 Posted March 17, 2018 Share Posted March 17, 2018 3 minutes ago, Spinneyhill said: All the differential carrier and cover bolts have one end in the air and one in the oil. The oil works its way up the threads. it is hard to stop it. There are thread seal products available. The threads must be spotlessly clean before you put it on. The rear cover may be warped by over tightening. It is pressed steel with a cork gasket. If the gasket is squashed at the bolts, the cover warps. Remove, flatten cover flange, refit with new gasket and sealer. YES! A lot of people feel the need to over tighten these bolts. I did it myself to my 1931 DH6 rear end bolts and stripped one when I was 15 years old and didn't know any better. As Spinneyhill said, there may be little ridges around the holes in the cover if someone over tightened it. I usually hammer them back to flat on a flat, steel surface. Link to comment Share on other sites More sharing options...
Spinneyhill Posted March 17, 2018 Share Posted March 17, 2018 I have also seen a ring of flat 1/8" x 3/4" or so steel under the bolts against the cover. The ring of steel prevents the tendency for localised bending of the cover around the bolts. Not original though. 2 Link to comment Share on other sites More sharing options...
C Carl Posted March 18, 2018 Share Posted March 18, 2018 21 hours ago, C Carl said: What weight oil , how much does it drip , and precisely from where ? - Carl Well ? Link to comment Share on other sites More sharing options...
Mars Posted March 18, 2018 Author Share Posted March 18, 2018 90 weight, drips at bottom of cover, not a lot. Probably shouldn't worry about it. Reseal with new gasket prob best bet Link to comment Share on other sites More sharing options...
C Carl Posted March 18, 2018 Share Posted March 18, 2018 Yes. Also you can change to 140 weight at the same time. Or a heavy multi grade , 140 being the top number if that is more comfortable for you. I once stopped a pinion seal leak (!!!!) by doing this. - Carl Link to comment Share on other sites More sharing options...
Mars Posted March 18, 2018 Author Share Posted March 18, 2018 That's agreat idea, thanks! Link to comment Share on other sites More sharing options...
Mars Posted March 18, 2018 Author Share Posted March 18, 2018 Straight 140 or multi wt.? Link to comment Share on other sites More sharing options...
Spinneyhill Posted March 18, 2018 Share Posted March 18, 2018 (edited) Multi. I don't think there are any copper containing metals in there, so an oil of your choice. Any synthetic are better than all mineral oils at minimising wear. The multigrade (e.g. 85W-140) means it will take less power to drive the diff. when it is cold - it will behave like a SAE 85 grade oil under shear. The check for oils with EP additives, some of which are known to attack copper, is the Copper Strip Corrosion Test, ASTM D130. A 1a result is best, 1b is nearly as good. The test result is often given on the SDS. If you can't find it, look for another oil. Gary W gave a good write-up about it in his Buick restoration topic in the Buick Pre-war forum. When I changed the crown wheel and pinion in my 1930 DC Dodge Brothers (same as CF), I went to a lot of trouble to keep the oil in. It lasted about 5 years. I used new gaskets, straightened the cover to sit fully flat, used thread seal on all the bolts... No, it now drips at the back cover. I periodically roll under and wipe it clean. A collapsed cardboard box on the floor absorbs the oil - just replace it from time to time. Edited March 18, 2018 by Spinneyhill (see edit history) Link to comment Share on other sites More sharing options...
Guest Posted March 18, 2018 Share Posted March 18, 2018 A friend of mine painted his cover, bolt heads, gasket edges and housing. He said it never dripped anymore. Just had to touch up the paint any time he took the cover off or the plug out. Link to comment Share on other sites More sharing options...
C Carl Posted March 19, 2018 Share Posted March 19, 2018 The pinion seal leak I stopped was done on a 1973 Cadillac. I did use a multi. The car was a daily driver which sometimes took long distance trips at freeway speeds. For an old car which spends most of it's life in the garage , the case for a straight heavier weight oil becomes more convincing. I use straight 250 in my 1924 & 1927 Cadillacs , but that also corresponds with factory viscosity specs. Glad you didn't have a pinion seal leak ! But again , for a seldom driven relic , depending on the level of such leak , going up in viscosity should be considered. There are some fortunate guys who look for an excuse to tear into and improve anything on their cars. Sadly , although obsessive about some old car issues , I am not always spoiling for a mechanical confrontation. Such wrenching has become an almost impossible task for my beat up old body. Obviously , I just don't enjoy working on them any more. I'll take the easy way out , and hope it gives me more "saddle time". Luckily I can still drive them ! ? - Carl Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now