Hey. I pulled my rear end out to change the oil and inspect the diff and found pitting on the ring gear! I'm wondering how much of a problem this is. Is it ok to run it like this? Is this going to fail?





Any help with these numbers would be appreciated



Pitting is only on half of the gear. <br/>I tried to categorize this photo but the year only goes back to 1988.

 

WDM-J = Ford 9" rear axle / 3.50-1

6AD = Assembled the 4th week (D) of January (A), 1966 (6).

311 = Assembly plant code.

 

Hey thanks much!

 

Hey numberdummy,
Can you help me out with this?

 

F10 = F100 2WD

B = 300 1V I-6.

E = Mahwah NJ Assembly Plant.

820128 = 1966.

129" Wheelbase.

F = Light Blue.

F100 2WD .. 5,000 lbs. GVWR

281: 2 = Medium Blue Crush Vinyl & Medium Blue Wicker Pattern Vinyl / 81 = 81A Standard Cab.

C = Ford type 3.03 3 Speed Manual all Syncromesh Transmission.

08 = Ford 9" Rear Axle / 3.50-1 / 3,300 lbs. Rear Axle Capacity.

5,000 lbs. Gross Vehicle Weight Rating.

150 net HP @ 3,600 RPM

22 = Charlotte NC Ford District Sales Office, where the original selling dealer ordered the truck from.

 

Hey. I pulled my rear end out to change the oil and inspect the diff and found pitting on the ring gear! I'm wondering how much of a problem this is. Is it ok to run it like this? Is this going to fail?


I don't think anyone addressed your original questions.
That is a BIG problem.
Running it like that will put metal everywhere.
It will fail.
I'm pretty sure any 9" 28 spline will bolt right in. Although if it's not from a truck you may have to change the pinion yoke.
Try Car-Part.com--Used Auto Parts Market and set the search for your zip you may find one close by.

 

Thank you very much for your reply. It's not what I wanted to hear, but what I needed to know. If I bolt in a new ring will I have to go through all of that shimming and measuring? I don't have the instruments for that. All of the videos on inspection tell me to inspect, but don't say what to do if I find something.
Again, thank you for responding. I'll see if I can find something nearby.

 

I would say with that much corrosion on the ring gear that the pinion is ruined also. Your best bet is to find a good used unit and swap it out. You need to replace the ring and pinion as a set. And any time you take one apart you have to readjust everything.

 

Thanks again, Crop Duster
maybe I can find the unit. It's presently a 3.5:1. I was wondering if a 3.11 would give better gas mileage. There seems to be plenty of torque with the 300 six.

 

No such 9" ratio as 3.11-1 // 3.25-1 is the common ratio installed in F100's. 3.00-1 is less common for 1965/66, more common for 1967/86.

 

Ring gears can't be installed with a pinion gear from another gear set or vise-versa.

Ring and pinion gears are lapped together in matched sets at the time of manufacture.

Some gear sets are timed, some are not. It just depends on the ratio. There are non-hunting gear sets, partial non-hunting gear sets and hunting gear sets.

Information in the Ford shop manual making reference to the paint (timing) marks on the gear teeth.




hunting or non-hunting - Vintage Mustang Forums

hunting or non hunting gear ratio - Hot Rod Forum : Hotrodders Bulletin Board

 

Interesting stuff and something I neither knew or considered. So mine is a 3.5:1. Would that typically be hunting I hope? Thanks for the info. Much appreciated.

 

New gears for my truck!
$100 got this and the axle

 

Bought this from a guy about 45 minutes away.

 

This is a 3.00:1 ratio