VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 rear gears

I have a 37 master 2door town sedan. It tops out at 55. I will not run it above 45. As the motor sounds like it is topping out. Is there a rear end that will swap or gears that will bolt in. I do not want to change out the closed drive shaft. Any help and pics would be great.

LOVE MY 37

If your 1937 is a Master it already has a 3.73 ratio. The Master Deluxe had a 4.22 ratio.
The Master had a larger fan which makes the engine sound like it is really reving.
I drove my '39 for many years and long trips at 60 to 65 MPH. About 15 years ago I installed a 3.73 ratio and it runs smooth and quiet at 65-70 on the interstates.
A 1937 car will never match the quiet of a modern car that has an engine turning over at 1800 RPM at 65 MPH.

My'34, which had an older design engine ran along at 55 MPH with no problem

I am not suggesting that you drive this fast. Just a hint what yor car could do with an engine in good condition.

You're definitely not hurting it at 55. RPMs & car speed.

It may just be that all you advocates for hight speed - anything above 45 - are simply hard of hearing or some other reason for not hearing good.

I know that after a all day flight in a piston engined Beaver, Otter, Caribou or C-47 that on the way home I could hardly hear my 41 SD Town Sedan run. I couldn't even hear the missus yelling at me when I got home (always look for the silver lining).

I'm just saying that all but the most recently and low milage 216s are loud and sound like they are red-lining at anything above 45. And that is with me tinnitis too.

Tom, at least put a 3:73 in it. And don't listen too much to fine fellows as Gene or Tiny. They may be just encouraging you to blow 'er up. Think of all that rabbit in there on the rods a-pounding the crap out of the crank. Think of a jack-hammer. They probably got an engine to sell you. Mercy!

Remember: Driving a 216 at 60-65 is an adventure, i.e., not fun while it's happening.

You're welcome,
Charlie

Hey thanks. What can I get the gears out of? or a complete rear end.

If your car is a Master (leaf springs in the front) it already has the high speed 3.73 gears.
Perhaps your noise in coming from loose drive shaft bushings. This will make a drumming noise through-out the car and felt in the floor.

Tom,

The 3.55 gears are in '50-'54 powerglide equipped Chevy cars. I used a '37 car rear end in my '36 pickup to allow installation of those 3.55 gears and it's a huge improvement with no downside that I know of.

Street rod builders are a great source of those kinds of parts. To them that stuff is scrap iron that's in their way.

Different number of splines on the 3.55 pinion shaft I believe.
Would need to cut out the splined end of the drive shaft and weld in the fitting that the filling station advertises (if they have stock yet) .. find the old girl loves to run at 50.. but the fan is noisy.. slow down, take your time and enjoy the view.

The 3.73 gears are a drop in for a 1937-1939 so there is no good reason to go to 3.55 gears. The 3.55 will give only an additional 5% reduction which is 3 mph AT 60 mph.

HE SAID HE HAS A MASTER WHICH ALREADY HAD A 3.73 RATIO.

With the fan being noisy, you'll think the engine is turning a heck of a lot faster than what it actually is.

I'm not promoting the idea of burying your foot into the gas pedal, but the fan noise and lack of body insulation adds to the mix of "she's ready to blow apart".

As said, the 3:73 gears are in the car now. That is good.

Going from the 3:73 to the 3:55 (an easy swap, by the way) will not be noticeable by the driver.

Not worth the effort to do the swap.

Keep in mind, when the '37 was new, there were no Interstates, as there are today. Stop and go driving plus 2 lane country roads were the setting back then.

Car was designed for "that setting", not the 2015 setting of high speed, etc.

Tom,

I did a 3.55 rear gear swap into a '36 pickup and found it to be WELL worth the effort. The 3.55 pinion has 17 splines so a 17 spline socket from a '40 and up driveshaft is required.

You don't need any parts provider for that. All that is required is a 40+ driveshaft and a lathe. The back end of the driveshaft is chopped off and chucked in the lathe and the weld machined out. The 17 spline socket then falls out in your hand.

Similarly the 10 spline socket from your '37 driveshaft is removed and the 17 spline piece tapped in and welded. The whole driveshaft is chucked in the lathe and supported with a steady rest. Mission accompished!

Setting the ring gear-pinion tooth contact pattern is simple too because no crush sleeve is used to set pinion depth. Instead 2 shims are used and by changing their combined thickness the correct pinion location is set. It's easily checked with artists oil paint.

It's all very doable at home if you have or have access to a lathe and an arc welder.