I have a 99 SD V-10 F250 with a small pinion seal leak. The tags on the rear end have the numbers: 4L3010 5, 8A27, S421.B stamped on it. Do these numbers identify what rear end I have?? If so, do any of you know what I have?? I'd like to identify it before I start tearing it down and replacing parts. Thanks.

 

4L3010 5 means Sterling 10.5 with 4.30 limited slip. No idea what the rest means. I thought 99 and 00 had the 10.25 Sterling but could be wrong.