m923a2 differential question

[BonesM923]

Hey guys, I have been looking around but have not found what I am looking for. The other day I pulled my diff. fill plug to check oil level in diff. and when I was unscrewing it I noticed it had a little pressure; not a drastic amount, I just heard it venting a little as I unscrewed the plug.
Is this normal or do I have a vent stopped up? Also the truck has been sitting for 3 or 4 days not driven and still had a little pressure. Thanks for any info.

 

[MtnSnow]

Pretty normal to have a couple of psi buildup. You can also check to make sure that the vents on the axel/diff is not plugged shut. If you are worried about it being excessive pressure you can install a hose barb fitting in place of the oem vent and run hoses from the barb fitting up to a nice dry high place I personally would suggest putting a small filter or such on the end of the hose to keep little creepy crawlies from plugging up the hose over time..

 

[VPed]

The vents have a spring loaded check valve in them. The pressure builds until it unseats the valve against the spring pressure. It is designed in.