Had the rear pinion seal replaced in my Dana 80 2 weeks ago as it was leaking. Was going to do it my self but ran out of time and needed a tool to crank it to +500ft/lbs . Anyways sucker started leaking again tonight, haven't drove more than 500 miles.Haven't contacted the mechanic to see what it could be. I supplied the seal and he supplied the labour. Anyone have any experience with these and what could cause this? Are there better seals, as I paid around $25 with my parts jobber wholesale for the one I got. Thanks for any input on this guys.Rick

You should check to see if your axle vent tube is clogged, because if it is it will cause that seal to leak. The vent tube should be pretty easy to find, just look for a rubber hose coming off the axle that goes to nowhere. The place where it usually gets clogged is the hole going through the axle tube, so what I do is just find something that fits the hole and stick it through to unclog it and then put the rubber hose back on.

Ask him if there was a groove worn into the yokes sealing surface from the previous seal and possibly should have needed a speedy sleeve. or the drive shaft it out of balance or the pinion bearings are worn.

Ask him if there was a groove worn into the yokes sealing surface from the previous seal and possibly should have needed a speedy sleeve. or the drive shaft it out of balance or the pinion bearings are worn.

Thanks for the advice, drive shafts good as I replaced all the U joints about 7 or 8 months ago, and I am vibration free, don't look forward to Pinion bearings etc. Can the speedy sleeves be purchased at a parts jobber or just Dodge? I will look at the tube vent, mine fell down from it's mount last year and I just tied it up in the frame so maybe some crap got in as it doesn't have the vent tip in it anymore. I did let the open end of the tube point down so it wouldn't catch anything and drain in. Otherwise he will be tearing it apart next week and I will get the verdict. Rick

Speedy sleeve can be gotten at most any parts jobber just need the diameter of the yoke. U-joints and vibration felt in the seat of the pants are not the only vibration you can have a harmonic vibration you will not even notice. I used to work at a driveline/gear shop for a few years. The only way to know for sure is to have it spun up in a balancer. I would check for a groove in the yoke and pinion bearings first though, Also a big killer of pinion seals and bearings is the hanger bearing if you have a 2 piece rear driveline. when it goes bad the driveline jumpropes and you may or may not notice it.