1929 chrysler what weight gear oil for the rear and is it the same for the trans.

mikzjr....I have used modern 180 weight in the past; however the Model "A" guys have had the old style 600 weight reproduced. I think either should work. I have found the 600 weight quiets the gear box and rear end plus seems to make shifting easier in my '28 Lincoln.

thanks for the reply Harry. I have found 600 and 140 which would you use,and what was it back in 1929.

I guess your never to old to learn, I would have bet money the ans. was GL90. Thats what we used in 40s and newer. On todays car you better read the book. Thanks for the lesson. Dick

mikzjr....Refer to your owner's manual; also, check what is in your rear end and transmission. If it has not been changed but only added to over the years I will be willing to bet they are both filled with the 600 weight. As far as I know the 140 will also work. Like I mentioned in my first post the heavier oil seems to make early non syncromesh transmissions shift easier and dampens noise from it and the rear end.

It has been my understanding that the only reason 600 weights were used in the old vehicles especially rear ends are because the seals were not made of the modern material that they are today. The 600 weight makes it more difficult for leaks to occur with the older seals.

I have brand new modern seals in my rear end and use the 90 with no problem. Although it does make sense as Harry states the heavier oil makes for smoother shifting on the non-sync transmissions.

Dan