Differential Decode

These Numbers are from a 69 Wildcat Custom, trying to see what it has in the rear, thanks in advance for the help.

Pass Side: 8-1385785

Driver Side: B 14 2

before the 14 there is some kind of mark, not sure if it was once a number or not.


Also, on the lower drivers side there is a circle of dots with an arrow pointing at one towards the passenger side.

What does that mean, or what was it for?

thanks much

 

I believe one of those is the part number and the other is the date code. Neither are the gear ratio code. The odds are that you have the standard ratio which is a 3.07. If it is a peg leg it is code PG and if it is a posi it is PV.

The other choices are a 2.78 economy and 3.23 performance gears.

 

when we tested it just by spinning it came out really close to 3.42/3.55

would the posi code (PV) have been where my B is? or somewhere else (driver side facing forward)

and where could i look for the ratio code?

 

I would not rely on being able to accurately calculate the ratio by the number of drive shaft turns relative to one tire revolution. Also the ratios you posted were not offerred from the factory to the best of my belief. Perhaps a dealer install but I bet you will ultimately find it is a 3.07.

If you pull the cover usually you can read the number off the ring gear. If you post that number I think I can tell you the ratio.

The code you are looking for is on the axle tube and not the hogs head. I would look first on the passenger side front. On A bodies I have also seen one on the driver's side.

 

well we just sealed the "hogs head", so if i would have to do that to check it it can wait, as for the axle tube numbers... here goes nothing:

this is where i get confused...

i just went out and checked, found nothing, driver or passenger side, front back, top bottom....

am i just blind?

 

They are usually on the front side so you would see them if you were under the trans and looking to the rear. If it has been painted or ir has road debris on it, you may have to scrub the tube before anything can be seen. Usually there is more than just the 2 letter code.

 

is the code painted on, or is it engraved into it?

 

Engraved.

 

i cleaned the axle tubes on both sides, found nothing engraved in it.

either something is really stuck in there, someone covered them up, or theyre just not there...

im going to search for a picture of where they should be just in case, if not, can anybody post one?

thanks

 

Here is George's description:

http://www.buickperformance.com/axles.htm

 

ok ill check for it how they say

 

it would appear, as in the pictures i found, its more near the top than i can see, so when i pull the engine and tranny, ill pull the differential and paint it while im at it, check the #.

i read in one place standard gears were 3.07, some other place (not sure how trustworthy) said 3.42... still not sure