1931 Chrysler CD8 convertible coupe

[Vic Cheeseman]

I am trying to fine the rear axle ratio of a 1931CD8 Convertible Coupe with the 282cu.i. engine and 4 speed box Does anyone having the answer?

Edited August 21, 2017 by Vic Cheeseman
unfinished script (see edit history)

[Spinneyhill]

2nd series, 260 cu. in. engine, 4.1:1.

[keiser31]

6 hours ago, Vic Cheeseman said:

I am trying to fine the rear axle ratio of a 1931CD8 Coupe. Does anyone having the answer?

Do you need some 1931 Chrysler rear axle gears? I have a set that is from a CM6....

[Vic Cheeseman]

13 hours ago, Spinneyhill said:

2nd series, 260 cu. in. engine, 4.1:1.

Thank you for the information, I am in the process of buying this CD8 and wanted to find out what comfortable cruising speed I can expect. Since posting I see that I didn't mention it was a convertible which possibly has a slightly higher ratio, also I now have the engine number from which I have found it is the 282cu.i.  model with 4 speed box. Regards Vic

[Vic Cheeseman]

12 hours ago, keiser31 said:

Do you need some 1931 Chrysler rear axle gears? I have a set that is from a CM6....

 

[Vic Cheeseman]

Thanks for your reply and detailed photos, I am at present in the process of buying the car but will be in touch if there is a differential problem. Regards Vic

[c49er]

Transmissions (4 speeds) can be weak and hard to find parts for I've seen.

[Matt Harwood]

I have this 1931 Series III CD8 roadster in my showroom right now and it seems pretty happy at 45-50 with 4.10 gears in it. It's quick and energetic around town, but like most cars of the era, wasn't built for sustained high-speed travel. It will, however, loaf at a walking pace in high gear and pull cleanly. It will probably cruise at higher speeds without issues, but it will sound pretty busy and I am always concerned about throwing long connecting rods around at high RPM. Better to think of it as a sporting around-town car rather than an interstate cruiser. Note that it's not really a 4-speed transmission, there are just two options for first, low and VERY LOW. There's no overdrive or high-speed range. Brakes are fantastic, however.

 

I think it's one of the prettiest cars of the era, much longer and lower that most of the other cars built that year. It's so pretty, in fact, that I parked it right outside my office so that I see it every time I walk in. The CD8 is of the best-kept secrets in the old car world: performance and beauty in one reasonably-priced package.

 

Good luck with the purchase, I think you'll love the car!

 

 

[Vic Cheeseman]

Thank you Matt, you've filled me with enthusiasm after some doubts about buying the car!

[rocky1x]

The primary reason the l931 Chrysler CD-8 (and Imperial CG) transmission is weak is due to a factory design error in which the input shaft is cut off right at the splines and does not extend into the pilot bushing.  That causes excessive wear on the front bearing in the transmission.  By 1932, for the CP-8, they corrected the error and redesigned the shaft to extend into the pilot bushing solving the excess stress on the front bearing.  I have rebuilt two of these transmissions and driven thousands of miles in my roadster and have never experienced an older transmission shift in the same manner, double clutching does not work well, but a quick and precise shift is smooth and quiet, it is one heavy moose of a transmission, makes the 6 cyl transmissions look like toys.  The first time my transmission 'blew up' I was crossing an intersection and it stopped that heavy roadster so quickly that it lifted the car off the road and rotated it about 30 degrees, I still have many of the old shattered parts, including the input shaft that is factory produced without shaft going past the splines.