Teezebox

Alas, yet another pinion seal post yet, mine; however, is different. The pinion seal normally leaks right below itself and down the pumpkin. I noticed that mine is leaking on the round flange where the driveshaft bolts onto with the U-joint. The oil drops straight from the flange onto the ground with no "travelling". Is this still the pinion seal? I'm not too sure where to go with this but I'd like to tackle this project if it's just a simple seal or even u-joint. No play whatsoever either. Please help, I have a long trip from NC to FL in a week!

dcrabby

If it is comiing from the pinion seal, you should see a sling line on the under-carriage. That is a tell tale line of oil that is created on the bottom side of the vehicle and nearby components. The worse the leak the heavier the oil line. There may be some small lumps of grease if the u-joint has a zerk and has recentlly been greased

As you noted the lube is dripping on the floor. Ithink you have a bad pinion seal.

jamie930

Replace the seal and or least check the diff oil level.

I failed to do either when I was younger and I ended up replacing wheel bearing, axle shaft, brake drum, rear brake shoes, and all the bearing in the diff

Teezebox

I'll check the diff fluid and find out for sure. Now for replacing the seal, I've read its a simple job with the exception of counting the threads for the nut; It's all torqued a certain way..? Also, when pulling the flange off, do you need a gear puller (or something equivalent)? I'm dealing with standard tools but not scared to get a dirty either. Let me hear some suggestions.

jake_85

As in its leaking from where the pinion nut holds the yoke to the gear?? If so, easy fix, you can just drop the driveshaft, take that big nut off(i beleive it is 1-1/8) you can then slightly tap the yoke off the pinion gear shaft splines, clean the inner splines of the yoke, take some good black rtv and coat the inside splines. while your at this point you might as well put a new pinion seal in also. When you put the pinion seal in, pack grease in the back side of it around the seal spring, this insures the spring doesnt pop out of the seal during installation. Once the seal is in and the yoke is back in, tighten the nut only untill it get hard to turn, if you keep cranking on it, you will just smash your crush sleeve and the pinion bearings will be too tight. Use red locktite to insure that large nut stays. Have fun!!

dcrabby

Teezebox, I suggest that you do an internet search on 'HOW TO REPLACE REAR PINION SEAL" You will get videos that tell you how to do the entire job. and it is really quite easy. You will not need any exotic tools. Although an impact
wrench will be helpful in removing and installing the yoke nut, I've done the job without. The old seal can be popped out with a flat blade screw driver. The new seal can be installed using a large socket and 'gentle application of a hammer". You can get an install socket at many parts stores. There is no need to pack seal with grease. There is no need to pack yoke or pinion shaft splines with black RTV. Don't do it. Again, it is an EASY repair that you can do in a very short time. You will be very pleased when you are done and see how simple it is....

BUCKSHOT

Check the flange for wear as well while your in there, they are known for getting worn down and leaking, when I had mine done I had both the flange and the seal replaced. If you replace just the seal and the flange is worn, you will still have a leak and vice versa. Both parts are what I consider inexpensive and was worth replacing both while the mechanic was in there. The reason I know this is the mechanic showed me my flange when he took it off and indeed it was worn, so if I had just had the seal replaced, I would have still had the leak.

Teezebox

K

Teezebox

As you can see, the seal is clearly not soaked. I probably should had posted these pictures earlier but would you consider this the pinion?

StanF

I've had two issues with my pinion seal over the last couple of years.

First, I replaced the seal - there was a noticeable drip spot on the driveway. Problem solved.

About a year later, I found my vent hose was plugged with dirt, and the pressure was blowing oil out the pinion seal. It wasn't dripping - it was spraying oil all over the underside of the bed. Unclogged the vent, and problem solved.

Definitely don't drive the truck when low on diff oil