VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 power glide gears

I've read that power glide gears can be used to get higher speeds in older chevy's. Anyone have any experiences along this line? If so what years to use as donor cars? Can the entire rearend be swapped or just the gears? Any other concerns?
Thanks in advance.
Gene P
41 Chev Super deluxe

Hi bookie,

I assume you are talking about your 1941. The easiest upgrade for your car is to locate the rear end (either ring and pinion) or (complete unit) from a 1941 MASTER DELUXE.

Part number 604397 (Assembly, pinion and ring gear) will give you a 11:41 ratio.

Part number 604398 (Assembly, pinion and ring gear) will give you a 9:37 ratio.

If you change only the carrier that will be the way to go as it does not require the complete rear end to be changed.

If you find something it is a simple procedure to find the ratio. Either by reading it from the part or in the case of an assembled unit, by turning the driveshaft and counting the turns at the wheel. (Must keep the opposite wheel stationary).

The "rear end" from a 1950-54 Power Glide OR 1953-54 standard transmission car can be used.The PG has 3.55 ratio and the stick 3.70---either is an improvement but the 3.55 may be a little too extreme if you live in a mountainous area.They will result in a 10 and 13 percent reduction of engine speed.

What you will need is the center rear end housing and torque tube.This will include the drive shaft which is enclosed in the torque tube.

To remove from car the rear diff. cover is removed.The axles are removed .The bolts (nuts) retaining the center carrier to the banjo (axle) housing are removed.The U joint is split apart.Torque tube dropped in front at U joint and center housing or carrier pulled out forward.The ring gear and pinion will all be attacthed to this unit.Take the same unit from a doner car and install.This will require no setting up of gears etc.It would be a good ides to check and replace the pinion and side carrier bears though-and this will require the gears to be set up.

An adapter will be required to correct the speedometer error.Also have a shop manual to study the details involved in doing the various operations.

Either ratio will result in a 65 MPH crusing speed with ease.Also a 1 to 2 MPG increase in fuel milage.

A bit of confusion here.
Your 41 would be the (4.11:1) and a 50 -54 powerglide would be 3.55 and a 53 -54 stick shift passanger car would be a 3.70 to 1

Gene used the correct terminology of ratio. it is expressed as (3.70 to 1) or (3.55 to 1),

Raymundo was using the actual tooth count of the ring gear and pinion (11 teeth to 41 teeth =3.727272:1) and (9 teeth to 37 teeth = 4.11111:1) or anyway that is what it appears to me.

MrMack,

You are absolutely correct in your assumption. Sometimes it is easier to understand for the non-mechanically-inclined to use the tooth count. (Also the tooth count is the way it is listed in the parts book)(That is also the way it is listed on the end of the pinion gear).

Just reread Ray's original post.The 1941 Master DeLuxe did not use the 11-41 or 3.73 ratio.The 3.73 ratio was available on all 1941 Chevrolets as an option only.

The 1937-38 Masters and 1939-40 Master 85's had a 3.73 ratio standard only.

The 3.73 ratio may have been considered for the 1941 Master DeLuxe as the 1941 GM proving ground report published in the G & D years back listed a 3.73 for the Master DeLuxe test and 4.11 for the Special DeLuxe test.

It would be intresting as to how many dealers from the "flat lands" ordered cars with the 3.73 ratio.The 3.73 ratio was the optional economy set up from 1941-1949.!953-54 stick ratio changed to 3.70 which is the same as 3.73 -just used 10-37 gears.

Installing the 3.73 gears in my '39 (which are not the same as the 1940 and up gears) made 65-70 MPH sound comfortable.Power loss on the level not too bad.Downshifting required on hills once speed drops below 30 MPH.----but 35 or 40 in 2nd gear is no strain.Much better suited for Inter- state highways.

Chevy nut and Ray, I agree that the only sure way to know the exact ratio is to count the teeth. then look the parts up in a parts cataloge, I also want to say that Chevrolet is imphatic insisting that the ring and pinion gears be changed out as a pair since every 9 tooth pinion gear won't fit every 37 tooth ringgear. as many of these rearends are on the market one should buy a complete 3rd member when possible.

The answers to this and many more gear related questions might be on Web Page < http://la.znet.com/~c1937/RPM.htm >. If you have a 4 speed in your 41, you can use a 2.87 rearend before you start to lug in high gear on level ground. It's not a bolt on like a 3.54.
, 6.00 X 16" tires and 4.11 would spin 2960 at 60 MPH. 7.50 X 16" tires and 4.11 would spin 2673, 6.00 X 16" tires and 3.54 would spin at 2557. and 7.50 X 16" tires and 3.54 would spin only 2309. The engine has enough torque to run at 2000 RPM and starts beating babbit at 2500 RPM. Good luck.

Bookie
I recently replaced the 4:11 ring gear and pinion in my '41 with a 3:55 from a '54 powerglide. The results are tremendous. I can now cruise with the big boys.
Chevygene is an expert on almost any Chevy problem or question. He walked me through my gear change. He has already told you what your options are and how to do the change. Correspond with him direct email. chevygene@msn.com.
I don't know about California but here in Missouri we still have a lot of old Chevys and parts in junk yards and many individuals have a few cars sitting around. You should be able to find a rear end that will work. Be sure you know what you are buying. Make sure it is the "right" ratio and in good condition. Remember any used parts you buy will be old and may be worn out.
Check with Chevy Nut. He is a great guy.
Good luck JIM

You surely got that right JAR41, He is also a fine man and he is a credit to any VCCA event he shows up at. I am looking forward to seeing Gene again in Branson.

If you keep it up my head will get too big to fit in my car and I won't get to Branson.

Its hard to believe that its only a month away.We are still having snow up here in Wisconsin.

Will be coming back home thru (around) Sullivan,MO. on Sat. Apr.24 if all goes well.On the way down will be stopping in Tenn. a few days to visit my son.Then will be going over to Branson.

Chevgene who?? :confused: :confused: :confused: :confused: :confused: :confused: :eek:

JYD, YOU know ....old whatshisname, the guy with the big set of.......literature and a headfull of Chevy facts and numbers from up there in the Cheese country....Our midwest guru.

Hum............Who??? :confused: :confused: :confused:

Hay guys thanks for all the good information.
GeneP