Speedometer Gear Selection A833, 1968 Charger

[Chris 69]

Ever since I swapped the 727 to the A833, the speedometer has read high. Now the transmission has developed a leak at the speedometer cable connection point, so I'd like to fix both the leak and the speedometer issue.

Specs of the car: 1968 Charger, 440.

     - Trans: A833.
     - Rear Tires: P275/60R15.
     - Axle (per tag attached to it): 3.23 ratio

Per the calculations on the website: http://www.mymopar.com/speedometer.htm, my calcs result in 28". Therefore, it looks like the part should be 2838931 (Green).

Questions:

1. Do my calculations look correct?

2. What is a good source for this part? A google search for the part# above does not yield consistent results (maybe I'm doing something wrong).

3. The insulation on my speedo cable has failed. What is the part#/source for a replacement?

4. Any other parts I should have on hand to do this replacement?

5. How hard is it to replace the speedo gear?


I may call Brewers tomorrow as they have been my go to source for trans parts since the swap to the 4-speed.

Thank you for any input.

[John_Kunkel]

I have found that the actual diameter of a tire varies with the maker.

To determine the actual diameter, I put a paint daub on the tread face and, while the paint is still wet, roll the car until the paint daub leaves two marks on the ground. Measure between the two marks and divide that dimension by 3.1416.

In my most recent check, an advertised 28" tire was actually 26.75"....a 10% difference.

BTW, the numbers of some of the pinions have been superceded:

TOOTH COLOR PN#

24 WHITE 3410024
25 BLUE  3410025
26 RED  2538926
27 WHITE 52068149
28 BLUE 52068150
29 BLACK 52068151
30 YELLOW 52068152
31 GREEN 52068153
32 BLACK 52068154
33 YELLOW 52068155
34 GREEN 52068156
35 ORANGE 52068157
36 RED 52068158
37 WHITE 52068159
38 BLUE 52068060
39 GREEN 52068061
40 ORANGE 52068062
41 RED 2538941
42 WHITE 2538942
43 BLUE 2538943
44 BLACK 2538944
45 Yellow 2538945

[XH29N0G]

I would look would be Brewers performance http://www.brewersperformance.com/.  The pinion gears are straightforward to replace.  I also think Brewers has cables, but you can identify the part numbers and then do a more general search.  Good luck. 

[c00nhunterjoe]

brewers is my 1st choice for the gears. They have a respectable inventory on hand.

[Chris 69]

Thank you all for the info. I plan on working on the car Sunday, then ordering parts next week.