F/S 1937 to 1940 high ratio rear end. 3.77

[Bob Hoffmann CLC#96]

I had some rear ends put away for years. I went thru them recently. One turned out to be the rare 3.77 ratio, as opposed to the 3.92 ratio. This is the "pumpkin" only, not the axle housing. The MPB shows it fits all 1937 to 1940 Cadillac & LaSalle small series cars,50,52,60,60S,61,62. If you want to cut your RPM's or replace a bad rear end, here's your chance.
Please contact me directly at bobscads@comcast.net.
Thanks, Bob

[Stinson]

Oh, how I wish it would fit the 1937 85 series.
Ty Stinson
CLC22339

[robert G. smits]

Ty, why don't you buy a small series rear axle and substitute it or are the dimensions different?  Bob Smits #2426

[Stinson]

I don't know. I hope someone can come up with the perfect answer to this RPM reduction need in these car years. Suggestions have been a new modern automatic transmission, a new modern rear end, and the installation of a Gear Vendor unit all at a cost of about $3,000 or more.
Ty stinson
CLC22330

[Steve Passmore]

The small series rear end is a different dimension than the big series and some may argue that its not man enough for the extra weight, but more importantly I'm not sure the high ratio would do the clutch any good in the heavy car. My 37 small series pulls the gearing and is great out on the highway but its not the fastest off the mark at the lights, my 37 Buick with the 3.9 leaves it for dust but beyond 60mph the Cadillac sails past with a lot less revs, Although I like it I can see why it was a one years thing for Cadillac, if you lived in San Fransisco you could never park facing up hill, and constant city driving would be a pain.
Another aspect is the smaller series has different wheels so you would have to Carry two types of spares.
The custom overdrive is by far the best way to go as you get to keep your bottom gear and believe me there will be times when you need it.
I'm a firm believer that manufactures like GM did everything for a reason, the power to wight ratio would have been experimented with in great detail for all the different series and in all environmental conditions during development and they ended up with the optimum for all conditions even if you dont agree because you use yours just on the highway.
I have done an overdrive conversion on my 37 and coupled with the high rear end 60mph is just a light touch on the throttle and I can always kick it out when not needed, definitely the way to go, and relatively easy on a Cadillac, 25 years ago before there were companies who would do these conversions I fitted an overdrive with inner chain couplings into my Buick enclosed drive shaft, but thats another story.

[Stinson]

Hello Steve,
So you think the Gear Vendor overdrive is the way to go keeping everything as it is. This would keep the rear at 4.60:1 but let you kick it to 3.78 as an 6th gear overdrive.
Ty

[robert G. smits]

Steve. could you give us some more details on your overdrive conversion?  I have been reluctant to change the rear end ratio on my 32 in preparation for touring as it is pretty slow off the line as it is.  Bob Smits #2426

[Steve Passmore]

Yes Ty, I do think thats the best way to go considering theres no readily available rear ratio.
Bob, I couldn't go into the whole overdrive project here, suffice to say I wish these Gear vender's were around back then. My unit is a modified rear end of a 60s Chev overdrive gearbox that had its shafts cut and modified with sprockets and plates made to close off the front end and attach itself in the Buick torque tube, I removed it from the Buick because the sprockets failed on a 4 year cycle and had it modified yet again with UJs and its mounted amidships in the frame crucifix on my Cadillac with mounting plates back and front, its very cozy in there right now and the main issues is the shortness of the prop shaft on the short chassis models like mine, under heavy springing the angles are a little severe on the UJs, I'm investigating using constant velocity joints instead should I ever get a problem.
It would be crazy to go through all this when Gear Vender's can supply a ready made unit and from what Iv seen its much smaller so less of an issue with space under there. We have a company here fitting Laycock units, much smaller, but when I looked into these in the 80s the reduction was very small, not worth the effort and cost I thought at the time, but now with our fuel prices every little helps.

[Stinson]

Hello Steve, thank you. Having thought about all the offerings, ideas, experiences, and discussion I'm also back to the Gear Vendor but wanted to hear what you had to say about it. Also, the original shaft could be saved and in the future installed after removing the $3,000 unit and use the Gear Vendor on most any other car application in the future. So, an investment that could be saved and used again and again and not alter original car components sounds in order.
Many thanks to everyone,
Ty Stinson
CLC22330