64' C10 spraying rear gear oil ??

[john dob]

hi - i have a 64' C10 (292 4 spd, long bed) and drive it on the weekends as a work truck. last weekend after driving it i noticed a puddle a few inches accross of gear oil under the differental. i crawled under and there was gear oil on the rear, underside of bed and on the frame. the only place i think it could have come out of was a hole that i found on the front / passenger side of the rear housing (between the driveshaft and the axle tube) there was a hole in the center casting maybe 1/4" diamater. i thought this might be a vent hole but all of the vent holes i have seen were on the top of the axle tubes, this is not. did i loose a bolt or a fitting ? i appriciate any thoughts. thanks - john

[Sharps40]

Pics if ya can...but I still suspect it'll be the pinion shaft seal...with rotation a leaking seal will sling oil onto the bed and when stopped, drip on the floor.

[BR3W CITY]

Does it have a vent hole with a hose on it, and if so, is that hose wet/dripping?

[dallas71]

I have the same thing happening is that an easy fix? or do you need a rear end specialist to fix?

[bama63]

if the hole is just behind the pinion yoke, that would be the fill hole, its npt pipe thread and 1/2 " if i remember correctly.

[john dob]

not sure about the vent hole or hose. i don't see any. i was wondering if this hole i am seeing (to the left side of the yoke if i am laying under the truck facing towards the rear) is suposed to have a plug or hose on it that just came off. the hole i am seeing is small..........maybe 1/4" dia. or the size of a pencil. can't tell if it is threaded or not. i just don't see anything else around where the gear oil could have come out of. i will try to get a picture posted. thanks for the replys !

[1963c-10]

Hey john, some pics would help. Do you know if its a factory truck 12 bolt or has it been replaced?

[chopper john]

pinion seal