New axles for 37 Cadillacs survey

[Jim Stamper]

     I am pursuing having new 37 axles made for 37-50 and 37-60 cars that would allow the use of the 41 and later 3.77-1 or the 3.36-1 rear ends in those cars.  What other car series and whether they will fit the 38-40  50 and 60 cars will require a bit more research, which I am pursuing.

     As some of you know the later rear ends are stronger and have gearing more favorable to todays driving conditions. The problem has been the entire rear ends are too wide for the cars, and the 37 splines are different than the 41 splines so that way doesn't work either. These will be new 37 axles with the 41 splines so this is a bolt in, everything else 37 is retained.  There are plenty of 41 and much later rear ends out there that can work just fine for us.

     The cost may be as much as $1000 for the pair but if enough people are interested we should be able to get the price down significantly by having a run done. With numbers comes economy of production.

     These will be from a US company that makes axles for off road, hot rods and so on. Axles are their business, for many years.

     Anyone who is interested email or call me and I will see what can be done. If your car is a 38-40 let me know too, I am hoping these cars can be provided for too. I have already sent in my 37-60 axles and a 41 axle so some firm planning can be done.  I hope to have more information next week, I would like to be able to give some indication of numbers of axles required. This is a no obligation survey at this stage of course.

                                          Jim Stamper   CLC#13470     dstamp4@comcast.net     603 863 2621

[Jim Stamper]

     Thank you to those of you who have contacted me about this.

     I have found the 1947- ?series, and 1937 50-60 series have identical brake drum tapers on the axles as well as wheel bearings. I still have a 39 and a 40 to take apart and check, but it looks like they will be the same too. This is good news in that only one basic axle will be required and cut to exact length to fit the 37-40 year model they would be for.  They would all get the same 1941 spline cut.

     Attempting to go further with this I am very curious as to what taper the larger series have and do they take the same wheel bearing and rear end gasket as the 50-60 cars. In other words, can this axle and newer rear end be used in the larger cars housings. They need better gearing far more than the 50-60 cars.

     Does anyone know these things? Or have a spare brake drum that could be plugged and hot wax poured into to make a cast of the taper so I can compare it to the 50-60 axles?  If possible can anyone do a tracing of the rear end gasket and the backing plate to housing gasket?  This could yield good information and move this along, or stop that idea dead if they are different.

                                           Thanks;   Jim Stamper CLC#13470

[Mike Simmons 938]

Jim- Just looking through my old Hollander Interchange manuals,  and they show that the small series 1937-50,60, 65 and 70 use an axle with splines at both ends. The bigger cars, and all 38 and later (this is a 1948 edition so later means 47 )use the tapered and keyed outer end. Are they right???
Certainly doesn't sound like your car has splines at both ends.
Mike Simmons (938)

[Steve Passmore]

No, their not right Mike, I have found masses of discrepancy's in Hollanders. All my cars have a spline inboard and a taper outboard, that's  36,  37,  and 38.  by the way Jim I can tell you the 65 series and up uses a different axle bearing for sure, but I cant say if the difference is in the OD or the ID or the width.

[Mike Simmons 938]

You're absolutely right, Steve. Shop manual says all axles are keyed  ( and obviously tapered). Before I added that comment about the splines, I checked the brake drum category, and the 37-50,60 had one number not shared with the other Cads so I figured Hollanders was right. My bad.
However- Jim: I have an axle that came with almost a car's worth of 40-75 parts (purchased to get the Fleetwood rear seat clock back in the day). The inner splined end broke off leaving only about a 1/2 inch of splines. I have saved it some 35 years because it has a good bearing, and I have a 40-75. But I don't have an axle press. SO-if I send you this  heavy dude at my expense, can you have the bearing pressed off and return it to me? You can keep this monster to experiment with as you like.
Mike Simmons

[Steve Passmore]

I can understand why the drums had different numbers Mike, the larger series drums are a different animal altogether than the smaller ones. bigger, wider etc.    Main difference from Jim's point of view is the taper but also the bearing surface, I should love to be proved wrong but I bet the bearings surface was much bigger on the big series cars. Everything else is bigger, so I just cant see that being the same as the 50/60 cars, fingers crossed.

[Edward Hurst]

Jim,

I would not recommend the rear gear to be a 3.36 because it would make for difficult starts in first gear.  The 3.77 is the absolute tallest gear that I, personally would recommend. It would be different if the 37 didn't have such a tall tire.  I have been talking with Ty Stinson at length to get a better grasp on the differentials that can be used.
Being a Street Rod builder, I know that differentials can be cut down to narrower widths.  The problem is that I don't have the specifications of the axle.  I am a Journeyman Machinist and Certified Welder.  If I could even get a picture of the desired axle so I could get an idea of what you need to make it work.
Perhaps you can answer a question for me.  Are the thermostat louvers the only type of thermostat that controls the engine temperature on the 37?  It has no engine thermostat?

[Steve Passmore]

True Ed, Up to 1941 the louvers were all there is controlling engine temperature..

[Jim Stamper]

    Thank you for your comments Ed.

    We really haven't had a discussion on the type of driving we are doing and that does have a real bearing on the gearing we should chose. I believe the original thinking when the cars were built was the belief that the passenger should be disturbed as little as possible. The car should be able to slow down to a walking speed and stay in high gear and accelerate away with as little fuss as possible. That is easily accomplished if the rear end gears are low enough, but it was also undesirable to start off in low gear and have to shift immediately, so Cadillac used a fairly high first gear, so starting was comfortable too. 

     My 37-60 coupe came with one year only 3.69-1 rear end, but at 45 MPH I am looking for another gear to shift into. If I was doing city driving I would be content to leave things as they are, but I live in the country so higher speed driving is much more my usage. I have to drive 10 miles to get to the one stop light they have.  I do have a long steep hill on my road to get to my house and currently I can go up that hill easily without downshifting. With the 3.36-1 rear end I more than likely will have to go down to second, but in the 40 years and many more modern cars with standard transmissions I have owned, nearly all, if not all of them needed a downshift to get home. So I am willing to tolerate a downshift if I must in the interest of more comfortable road driving.

     There have been a couple of contributions from members in old issues of the Self Starter by people who went to 3.36-1 rear ends in their cars successfully, of course with some difficulty as we know, Cadillac did not make it easy for us .

     I would say the rear gear selection is a matter of intended usage. Certainly not the thing for stop and go driving, but for the open road we shall see. I will be keeping my old axles and rear end in case I am not happy with the 3.36-1.

     As for a modified Ford 9" for the Cadillacs, if we are willing to alter the car there is a lot to be said for them. They came in several different widths, probably one would fit without narrowing, and the number of different ratios compared to Cadillac is astounding. There must be a ratio for any use. The rear end is easily changed out, parts are readily available and many people know all about how to work on them and they are easy to find in the wrecking yards and inexpensive as these things go. I am not quite ready to abandon Cadillac yet.

                                                      Jim Stamper CLC#13470

[Bob Hoffmann CLC#96]

Jim,
I'd like to applaud you for even considering this project. I think you will be limited to doing only the small series cars. IE 50,60,61,60S,52 & 62.
Good Luck.
Bob

[Jim Stamper]

     Thank you Bob.  Mike's axle will quite possible tell the tale about the larger car, either with the taper or the bearing size. Either could put the larger cars out of the running.

                                      Jim Stamper CLC#13470

[Mike Simmons 938]

Jim- I can use some dividers and give you some end to end measurements of the 75 and of a 39 LaSalle axle  as well for comparison. Just by a casual eyeball, the 75 is significantly bigger. Wait! Just went to other sources: New Dep  Bearing cat-Small series 1937-42 all take #88128; big guys-e.g. series 37-70 etc to 1940-90  (except 37-90) all take D-88609 through 1940. The wonderful Victor seal catalog of 1941 gives me seal dimensions  as well. Small series from 37 to 41 all take their 49232 axle seal(1 9/16 x 2.762); big guys(37-65 to 40-90) take 49283 ( 1 29/32 x 2.879).  I could give you axle lengths from Hollanders, but I  don't trust them anymore.
Mike Simmons 938

[tozerco]

If its of any help to anyone, I've got two sets of rear axles and bearings for '37 75 series out at the moment. Can photograph and measure whatever you want.

Regards,

[Jim Stamper]

     The axle lengths are of no real importance but the other dimensions are.  The two most important factors are the taper, which if it is the same angle, but slightly larger might still be usable with one CNC program on a larger diameter shaft. A CNC man would have to comment on how flexible those programs are. The other one, looking less likely, is whether the 41 and later rear ends fit the larger series housings.

     If they don't fit something may well still be done with those housings by cutting out the actual bolt pattern from the 41 housing and grafting it into the larger housing and resplining the original larger series axles. 

     Refer to the article with pictures on the AACA site of the guy grafting in the Packard bolt pattern and rear end into his Hupmobile housing. Good story.

                         Jim Stamper  CLC#13470

[Brad Ipsen CLC #737]

The 38, 39 and 40 large series cars are different in every dimension to the small series cars.  I do not know of the taper is the same or not but the nut is bigger and the base is bigger.  The third member is bigger in every way and the outboard bearings are bigger in every dimension.

It has been many years now but a friend did a modification to his 1940 52 series axles to fit in a 41 third member.  It was done not at the splined end but by re-cutting the outboard end.  I have some 41 axles now and at first look I am not sure how this was done.  I have asked but he does not remember.  The 41 axle is longer but in making it shorter the area where the bearing would go has to be built up.  I assume then that his machinist had to have this part of the axle welded up to a bigger diameter to make this work.  the rest is just a matter of cutting the taper and threads further in.

[Stinson]

If its of any help to anyone, I've got two sets of rear axles and bearings for '37 75 series out at the moment. Can photograph and measure whatever you want.

Regards,

Hello John. Good to hear from you again. Can you provide the fowwowing:

"If you can get me some measurements of your differential from backing plate to backing plate, and a measurement from the backing plate (inside) to the outside of the wheel mounting surface, OR, the total overall length from wheel mounting surface to wheel mounting surface, I can probably find you something that will work on your car and try to retain the same 6 lug bolt pattern.  I would also need the center to center of the rear leaf springs and a picture of the mounting surface (spring saddle)".

Thank you,
Ty Stinson

[Stinson]

Hello John,
Can you give me the wheel to wheel mounting plate distance for the '37 75/85 series?
Many thanks,
Ty Stinson
CLC22330

[tozerco]

Ty,

One small problem.... My second car and its rear end are at my nephew's farm about 40 mile away and I won't get to it for another week or more.

I can take measurements off the rear end housing I have at home and add bits to get you backing plate to backing plate dimensions but "wheel mounting surface" is actually the face of the brake drum. I have these here but would almost have to reassemble the entire rear end to get it for you. I will, however, see what I can do.

I do have a set of original rear springs and a set of new ones from Eaton Springs in Detroit that I can measure. I suspect there might be some small differences because the springs are not under load and because the original ones have lost all their "boing". When your man says he wants a photo of the "mounting surface (spring saddle)" does he mean the front end of the rear spring or the back end? The front end is a threaded pin through the "eye" of the spring and a U-shaped bracket onto the chassis. The rear is a pair of flat shackle hangers with a threaded pin top and bottom - the top through female threaded bushings in the chassis and the bottom through a rubber bushing in the eye of the spring.

Regards,


John Tozer

[Stinson]

Hello John,
Thank you for your efforts. We can certainly wait for the two weeks and save you some unnecessary work.
Many thanks,
Ty

[tozerco]

Ty,

Let's see if we have answered your questions:

The dimension from the milled finished end of the rear axle housing shown in the "Rear Axle Housing End" to the same milled surface on the other end of the Rear End Housing is 56 1/4 inches. This milled finish is the surface that the brake backing plate sits tight against - see the second photo.

I will try to answer your other questions in separate posts....