i have a 2005 ford expedition. The label on the door under "axle" reads 15. For the life of me i cant find what 15 means. Dealership said i have 3.31 but they scare me a little. Hoping someone could tell me for sure. I have never seen "15" anywhere.
thanks

 

I can tell you that means you have an open differential, no traction lock. All traction lock are coded with a letter. Theres a list somewhere on this site.

 

I can't find "15" anywhere, but others ending in "5" are 4.10's. Crawl under and read the tag on the axle itself and post it.

 

I looked to and could find nothing on a 15. I would be surprised if it was a 4.10 on an expedition. On the F150, you can only get those with a HD payload package, 8200lb.

 

Is it possible that the first number is not a one, but a poor number/letter? A 45 is an open 3.55 and an R5 is a LS 3.55. Could it be a poor "R"?