Rear Diff Tag

Straight6 · Aug 16, 2004

I have been searching and can't find the info I am looking for. The tag on my rear diff reads:
top left to right WDM-BC2 6FD
Bott left to right 3.00 9 386D

Can someone decode this for me? The engine is a 300I6 w/OD 4sp manual

STLKIKN · Aug 16, 2004

I am not sure what info you are looking for,
but you have an open 3.00:1 differential.
You didn't mention the year of your truck, but if the tag was bolted to the front of the differential housing, and it is a front loading gearset and centre section, you have a 9" differential.
If the tag was bolted to the rear of the diff and you have a removeable cover, then you have an 8.8.

Straight6 · Aug 16, 2004

I'd like to know what the numbers mean. The Bronco is an 83' the tag is from the rear diff.

STLKIKN · Aug 17, 2004

Hmmm Ford assembly codes, sorry, I can't help with that.
And I am not sure what year the changeover occured from the 9" to the 8.8 rear diff. But if the tag was on the FRONT of the REAR diff you have a 9". If it was bolted to the rear cover of the REAR diff, it's an 8.8.
There used to be a couple of dealership guys lurking on the site, maybe they can help you out.
Good luck

stinger · Aug 17, 2004

I used to work for a ford dealer and the parts man could tell me anything other that type of diff ( open, limited) and the axle ratio . good luck

Justshootme84 · Aug 20, 2004

THe top row is some of the "bill of material" numbers for parts compatability. The bottom row gives you the gear ratio (3.00, or may be 3.08), Ford 9" rear axle. Get a free catalog from LMC Truck, and it will give you that info, plus how to decode you V.I.N. #. It's also a great place for ordering parts.

cjbronco · Aug 24, 2004

I have a 82' 300 and I have a9" in there. I haven''t decoded mine for i just returned froma trip to NC and will hopfully start the emoval of my 9" on thurs, but im not sure what they code out to be. Are you taking out the rear or just wondering?

Straight6 · Aug 25, 2004

cjbronco, I have some noise in the rear drive line and I am trying to find it. I removed the drive shaft from the diff and found has about 15 degrees of slack and a rumble when I turn it by hand. Also the slip yoke and/or the drive shaft is worn out. Most people I have talked to are telling me that if the gear ratio is a 3.00 I should replace it with at least a 3.5 or my 300 six will feel like a four banger so, to make a long story medium length I am just trying to get as much info about the diff as I can in case I need to replace or rebuild it.