I have a '86 F350 with 4 speed manual transmission. There is evidence of slight oil leak around the differential. I would like to check the lube level but can't see any level check plug or filler plug for that matter. Can anyone tell me how to check the level and what viscosity lube oil is required? Thanks.

 

look at the drivers side of the pinion snout, see if there's a fill/check plug over there. If so, pull the plug and fill with your choice of gear lube until it starts dripping back out the hole.

Justin

 

Thanks, Justin. Just as you indicated. Had to scrap away some dirt but there it was.
Rick