1937 Terra diff

barrysweet52

My 37 Terra Sedan diff has the back cover bronze welded on by some previous owner. While it doesnt leak, I cant remove the cover to clean or check. I have pulled a diff out of a wrecked 37 Terra ute. It was made by a different maker as it had no bolted rear cover. Do both diffs used in 1937 use the same crown wheel/pinions. Are the ratios for utes different to sedans.

I believe I have the standard ratio in my sedan and would love to change diff ratios to get a slightly faster touring speed. Unfortunately there are a lot of hills around so I believe I would lose performance on the hills if I changed ratios. Any comments? Regards, Barry

Jon B

The factory rear axle housing -- at least as it left Jefferson Avenue -- was one piece. The entire differential carrier -- on the front of the housing -- was unbolted and removed. So, if by 'differential' you mean the entire axle unit, you may have a differential that was installed by a previous owner from another brand of automobile. Unless I'm misunderstanding your statement. There is no bolted rear cover, no welded bronze cover. Hudson offered only one rear axle and housing, though they offered a number of gear ratios.



If you did have an original "ute" (or "pickup truck" in the States) rear axle assembly, it would most likely have a 5-1/8 to 1 ratio. The standard passenger car ratio would have been 4-1/9 to 1. There were three other ratios offered, the 'best' (for Australian driving) being the 3-5/9 to 1. Possibly, cars shipped to Australia would have had this, standard....I dunno. As you may know, Pat MacDonald in England, offers reproductions of these for sale.



I would think that the Terraplane engine -- especially in the dual-throat carburetted version with 101 hp -- can handle this, unless you'r in the mountains. In this case you might look into fitting an overdrive. Several of us in the States have done this. The most readily-available overdrives are the 1941-1952versions, which will require that a steering column gearshift lever be installed, since they can't easily be adapted to a floor shifter. (The 1952-and-later OD transmissions from Borg Warner would be ideal since they're easily converted to floor levers, however they're too long to fit in front of the X member in the frame.)



One would assume that Hudson overdrives were quite popular in your country and thus must still be quite available.



The steering column-mounted gearshifts are not, of course, authentic in a 1937, but Hudson did offer a retro-fit kit in the late 1930's, to convert floor-shifter 1937-8-9's to the column shifted 'single lever' trannies....so it would not be totally out of place.

[Deleted User]

G'day Barry,



There is another question to be answered here as well. As we both know Ruskin built the Terraplane sedan and ute bodies here as well as Hudson sedans.



What we don't know is that did they or did they not use the same chassis on the Terraplane sedan as to the ute in Australia. I assume that the American built Terra sedan and pickup are different in the way of stiffer chassis, springs, and diff ratios in their pick-ups.



Please correct us with this readers.



In Australia all drive lines, chassis, front ends including gaurds, grill assembly, hood etc were imported and then the bodies added here and

painted. Even IF the American built sedans and pick-ups were different, Australian versions could still be the same!



I think the diff in Barry's ute was replaced at one stage with a different brand.

This brand is called X...



Good luck Barry. PS, Are you going to Toowoomba later this year.