VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 ratio 1940 chev rear axle ??

anyone know what ratio 1940 chev car rear axle is? will it fit under a 38 sedan ??

It could be a 3.73 if from a Master 85 or a 4.11 if a Master deluxe or Special Deluxe.
The Master 85 was the least common of the bunch.

The 1940 rear axle and torque tube assembly will not direct swap into a 1938 as the front of the drive shaft has a different spline count, 17 for 1940 compared to 10 for 1937 to 1939

Tnx for the info,just got a 3:73 put in MD 1938 sedan ..what a PIA ..have not got it ready to try yet ..sc

Bigpine,
so what was bad about installing the 3.73? Some of us would be interested in that information.

OK here's my take on rear axle swap..car 38 MD 2dr sdn with 4:22 rear..bot a damaged 38 3:73 but got it repaired..so in it went..put 2 sets of jack stands under frame just ahead of spring perch, remove axles by removing set screw on ring gear cage remove 4" long pin and block,remove U washers one on each axle,pull out axles about one foot,next problem removing u-joint bell it is locked in by emerg brake cross shaft,had to remove trans mounting nuts and jack up engine and pry it off great planning by GM folks.next unhook emerg brake rods fairly easy.but must loosen brake cable support WD40 and vise grip them and pushing them back to rear,if you don't can't get rear axle to the back far enough.next remove 8 large nuts on spring shackles remove spring shackles,next disconnect brake line,need to bleed brakes when put back on..remove rear cover on banjo and drain..then remove front banjo nuts about 10 or so..next pry with big bar to slide entire axle back about 6 in. and remove front bell but not u-joint except if you want to replace it..I chose not to it seemed in good shape but I did have a new on hand..next with 2 people slide screw driver in front of banjo and pry off entire torque tube,it helps a lot to keep rear axle from rotating as you try to get old stinger off..clean as needed... pitch old tube in the ditch..clean the new replacement tube and gear set... to not take this apart as you will loose the gear setup...put 3:73 tube up and fight to get it in but not to bad of a job..took 2 days and a lot of swearing and lots of dirt and grease in hair and arms..might add putting rear shackles back on is not easy another great GM idea best to tighten front , put car weight back on axle and pound them on..I do not ever want to do this again..drove car today on freeway about 60 or so, big improvement over 4:22 car seemed to ride better as far as wheel hop and shimmy goes.sc PS remove nuts to rear shocks also my shocks still worked fairly good after 80 years

Mistake on above text on rear axle change out....when I say spring shackle I mean spring U bolt,spring shackles are never in play except when one flips which it did for me because of improper jacking under rear shackles..sc

Remember your speedometer is now 10 percent slow. When the speedo. is showing 60 MPH you are actually going 66 MPH.