VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 4.11 rear end to 3.55 gear change

my 1940 special deluxe has 4.11 rear end. how difficult would it be to upgrade the rear end to 3.55 rear end? what years and models have the rear end gears that i need to be able to drive at highway speeds?
i know about the new 3.55 ring and pinion gears and rebuild kit would cost about $800.00.$400.00 for the ring and pinion gears and $400.00 for the rebuild kit. but this is money i can save by putting used gears in from other models.
can a "grease monkey" install the gears his self or do you have to have special tools.
any help or suggestions?

thanks, kw

Choices for 1940 gears.
You can find a 1940 Master 85 (straight front axle car) and use the complete torque tube and carriew from it . It had a 3.73 ratio...or use its ring gear and pinion.

Find a 1950-54 Power Glide car (3.55) or 1953-54 stick shift car (3.70) and use the ring gear and pinion and the case the ring gear bolts to. Thats the only parts . They must reset and installed in your differential. Not impossible to do and a dial indiactor is needed. I installed a set of new 3.73 gears in my 1939, I never did that before although I had parts back ground experiance and was around when this was commonly done in the dealership.
Note that to use the later gears the case the ring gear is bolted to must be used.
I drove my 1939 for many years with the 4.22 gears that the '39 used. Many cross country trips. Kept speed around 60 MPH. A few years ago I finally installed the new 3.73 gears that I had on the shelf for years (along with the proper speedo. gears). This made high speed crusing much better and can run at 65 to 68 easily. The milage at Interstate speeds increased by about 2 MPG. The high gear power below 50 MPH dropped off, especially on hills. It was well worth the trade off.
If you would do this I would recommend replaceing the pinion bearngs and the side carrier bearings.
Could talk you through the operation and a shop manual is a must.
For 1941 and up the later torque tube and housing can be used. The 1940 torque tube is a different length and fits 1940 only.

Take Chevgene up on his offer to walk you through the change from 4:11 to 3:55 rear end. Gene helped me on replaceing the rear end in my '41 Coupe. One of the best things I have done to my car. Thanks again Gene for all the help you gave me on my "41. I have really enjoyed going to local cruises, car shows, parades, etc. I went to Springfield, Ill. VCCA meet. The local VCCA chapters are too far away for me to participate.
JIM JAR41

KW,
I believe you can get a complete torque tube assembly including gears, carrier, etc. from a 50-54 powerglide car and have it shortened to the length to fit your car. I have not checked the numbers lately, but I think all the axle and u-joint splines will match. I did this once and plugged it into a '48 passenger car housing to speed up my buddy's 1951 1/2 ton. The wheel track width was a little different. I moved the spring mounts and should have changed the brakes to the bendix type but did not.

Mike

thanks guys, as soon as i locate one, i will get with gene and see if he will walk me through the change over.

here's to the VCCA

kw