1952 Buick Roadmaster gear ratios

[rapidride2]

I am 37 so obviously this all original 52' roadmaster 2-door is before my time. It was rescued from a farmers field and is in rough but extremely original condition.

After installing all new rear brakes i decided to install new rear lube. In doing so i noticed that it has a 4.10 gear ratio. Is this rare? How is this going to react with the dynaflow in specific on the highway? Once again the car appears to be very original.

[Joseph P. Indusi]

According to the 1952 Shop Manual, there was no 4.10 to 1 ratio differential for the Roadmaster with Dynaflow. The station wagons with syncromesh standard transmission did come with 4.1 to 1 gears. The gears in your car are not likely original but perhaps this was a special order.

Joe, BCA 33439

[rapidride2]

Hmmm, interesting as i am definitely sitting on a 41-10 gear set. I'm not sure if they did much special ordering back in the early 50's or it has been replaced at some point in time (the car is very original and has set for 20+ years on a farm. or quite simply it may have been Buick's call as maybe there was a surplus of this gear sets that Buick needed to use?

[Guest RACEJones]

Here a couple of links concerning Buick's differential gear ratios. The last one is an interesting article from New Zealand and it specificaly mentions "differential ratio changed from the standard 4.1:1 gearing to 3.6:1." I hope this helps answer some of your questions.

1952 dynaflow / gear ratios [Archive] - Team Buick

1948 Buick Roadmaster & 1952 Buick Super – Black Beauties – 216 Classic cars

[sean1997]

Here a couple of links concerning Buick's differential gear ratios. The last one is an interesting article from New Zealand and it specificaly mentions "differential ratio changed from the standard 4.1:1 gearing to 3.6:1." I hope this helps answer some of your questions.

The 1948 Roadmaster with manual trans did come standard with the 4.1:1 gears with 3.6:1 optional (Dynaflow was 3.9:1 for first type and 4.1:1 for second type, no option). The Dynaflow was standard on Roadmasters in 1952, and as stated above, 4.1:1 was not available according to the factory service manual. The manual states that 3.6:1 was standard on models 72R, 76R, and 76C and that 3.9:1 was standard on model 79R and optional on models 72R, 76R, and 76C. Of course, like the post on the Team Buick forum says, it would be easy to swap from another year.