Plymouth Owners Club

General Category => Technical Discussion => Topic started by: jd2ksilver on November 07, 2007, 05:00:44 PM

Title: Stamp on my rear end
Post by: jd2ksilver on November 07, 2007, 05:00:44 PM
Hey all , been awhile since I have posted here.

Question, on my diff I have 39F stamped on the top and bottom.  Does that mean 3:9? 

Its a 52 P23 and I understand they came with the 3.9 with a 4.1 as  option in hilly states.

Any clues?????


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Title: Re: Stamp on my rear end
Post by: Jim Benjaminson on November 07, 2007, 10:33:34 PM
Should be.  Easy way to confirm it.  Jack up one rear wheel - place a mark on the driveshaft and have someone turn the wheel one complete turn.  The drivesshaft should have made 3.9 turns in
the same time frame....
Title: Re: Stamp on my rear end
Post by: jd2ksilver on November 07, 2007, 11:13:25 PM
Thanks, will try that next.
Title: Re: Stamp on my rear end
Post by: David Pollock on November 10, 2007, 01:26:07 AM
The 39 is likely the number of teeth on the crown gear. As the pinion has 10, the ratio is 3.9 to 1. As for the F, I have not seen that before.  With one wheel still on the ground, rotating the other wheel will turn the driveshaft  1.95 ( half of 3.9) turns because of the action of the spider gears. Rotating the wheel twice will give you the correct count.
Title: Re: Stamp on my rear end
Post by: jd2ksilver on November 13, 2007, 12:03:53 AM
Thank you, next time its up I will try it and see.