Rear Axle Leak??

[gcburdic]

So I was under the truck today wiping down the frame and checking things out (because who doesn't lie under there truck and wipe down the frame....can we say...ANAL!!!....sorry....come by it naturally!!!) and a saw this leaking oil.....smells like rear gear oil...this pic is of the passenger side rear drum...the driver side isn't leaking (that I know of)......
So I didn't get time to pull the wheel and drum, but when I do, what am I looking for??....Has a seal gone bad??....If so, how easy (I hope) would it be to repair??....

FYI....I originally sand blasted this axle, primed and painted it with the old drums on it, then rebuilt the drums and installed it on the frame.....

Thanks for any input and help!!!

[walker]

Its either gear oil or brake fluid. Just pull the drum, if it is gear oil the slave cylider will likely be dry. You will need to remove the the diffy cover, then the C clip, slid the axle out, r+r the seal. You may consider bearings at this point as they are not too pricey. Also, since you are doing one side and have the diffy drained, just do the other too.
If it is brake fluid you will need to replace the slave cylinder.

[Sammy]

I wanted to add this. When you pull your axles and you see some wear on the race don't get too awful excited thinking you will need to replace the axle. They make a replacement offset axle bearing that will off set the original wear pattern so you won't have to replace the axle for wear.

[sleepertruck72]

I would say you have a slight leak at your axle seal. If that was brake fluid, I would say that paint would be peeling up on the wheel. I would pull it all apart and make sure it wasnt the wheel cylinders leaking also. It shouldnt be that hard to replace on yours. I replaced mine on my C20 and it wasnt hard, but then I didnt have to pull the diff cover on mine. I believe there is a thread on here on how to replace axle seals on a 1/2 ton. Anyhow good luck with it.

[beautimus]

yup, axel seal leaking. chock the wheels, jackup that side of the truck, put jackstand under frame. pull the wheel.
back off the brake adjuster, pull the drum. put drain pan under center cover.
remove bolts and drain axel lube. pull clip for that side and slide axel out of the housing. seal is now stareing right at you. this is a good time to go ahead and replace the axel bearing and seal on both sides of the truck. if you have the cash. there's a 50/50 chance that the other seal will start to leak soon.
it ain't to bad of a job to change the seal. once you get the first side done, your not gonna mind doing the other side. the 2 seals are 4 or 5 bucks a pop,
and the center cover gaskit is a couple of bucks. add maybe 15 bucks or so for new lube, might as well put fresh lube back in. so in total your out maybe 35 bucks to do both seals. if you elect to do bearings too, maybe 60 bucks out the door and you won't have to worry about this leak untill your to old to care. when you drain the axel look for metal shavings and stuff in the bottom of the housing. if there are no big particles, your in good shape. this could be a blessing in disguise.
after you replace the seal, you'll know if something is gonna break later,
or you'll know that the rear is not gonna give problems for a long time.

[gcburdic]

Excellent feedback guys....thanks so much!!!....

Now more questions....I have began to read through the Haynes Manual....

1. I have a semi-floating axle...correct?
2. What are the best oil seals and axle bearings to buy??....How do I ask/ order them from the auto parts store? (ie, GM 12 bolt truck rear axle...any special name for these items??)...I read somewhere Timkins brand name is good....
3. Haynes states that I need a seal installation tool, large socket or piece of pipe that matches up to the seal....any other suggestions...my tools are limited??....
4. Haynes states that I'll need a bearing puller that engages behind the bearing...and a slide hammer to extract...again...don't have these, any suggestions??....
5. Would high temp bearing grease be cool to use on the bearing and oil seal (Haynes suggests using "high melting point grease" to the oil seal recess)....

Also, been thinking about installing a PowerTrax Limited Slip Unit....obvoiusly, this would be the time...anybody got any feedback on this??...

Thanks for any input!

[d10s69c10]

Originally Posted by gcburdic

Excellent feedback guys....thanks so much!!!....

Now more questions....I have began to read through the Haynes Manual....

1. I have a semi-floating axle...correct?
It is pretty much a full floating axle

2. What are the best oil seals and axle bearings to buy??....How do I ask/ order them from the auto parts store? (ie, GM 12 bolt truck rear axle...any special name for these items??)...I read somewhere Timkins brand name is good....
http://www.moserengineering.com/Page...lbearings.html or when you go to the autoparts store just state the year model brand, their computer should pull up the right thing... its about 60% accurate. or get the part number off the bearing races themselves.

3. Haynes states that I need a seal installation tool, large socket or piece of pipe that matches up to the seal....any other suggestions...my tools are limited??....
While a slide hammer is the absolute easiest to remove it they can usually be removed with a BIG screwdriver and alot of fenagling possibly some heat... the pipe /socket is getting the new bearing in NOTE: this method is very many soft taps because you dont want to hurt the bearing.

4. Haynes states that I'll need a bearing puller that engages behind the bearing...and a slide hammer to extract...again...don't have these, any suggestions??....
homemade version... Piece of 1/2 allthread (1 1/2') a really thick washer or 2 say 1"OD held at each end by 2 nuts, a 8"x3/4" piece of steel pipe.

5. Would high temp bearing grease be cool to use on the bearing and oil seal (Haynes suggests using "high melting point grease" to the oil seal recess)....
Absolutely, unless of course your new bearings are sealed. i think this is refering to the front endo of the truck.


Also, been thinking about installing a PowerTrax Limited Slip Unit....obvoiusly, this would be the time...anybody got any feedback on this??...
if you have an extra 1k for getting C-clip disconnectors and get your gears reshimmed to specs for the install yes now would be the time.

I hoped that is some help.

[Tx Firefighter]

Couple of things to add to the above good information.

The above posters have kind of smoothed over the procedure, but missed mentioning one thing. Once you remove the cover, you will need to rotate the ring gear carrier until you see a little bolt head sticking out of the carrier. Remove this little bolt. It is a little pin. Now, let the center spider gear pin slide out of it's bore. Then, you can push each axle inward and the c-clip will fall out of it's groove.

To install the seal, you can use a piece of 2x4 wood and a hammer to gently seat it into place.

Be sure and check your differential breather to make sure it is open. Blow through the hose and make sure it isn't stopped up. When they stop up, heat from driving will cause pressure to build up in the differential and force it out of a seal, causing a leak.

[Sammy]

Tx is right about that pin. I have even heard of that pin being sheared off before. But believe the vehicle was in a collision previously. Don't forget to get some decent cleaning stuff to clean the inside of the cover. I thought the hardest part was refillling the housing without making a mess. I used a borrowed huge slide hammer and a pipe to install the new parts. Took about 30 min a axle and two beers before I was finished. Some of the better carquests can remove the bearings for you and install knew ones. Just a thought if you took the axles in when you got the parts.

[Legolas894]

All good stuff here. I put my seals on with a hockey puck and a hammer. Just get them even first.
Also, if you go on youtube, there's some guys taking the axle shafts off a '65 malibu axle. Here's the link:

YouTube - 1965 Chevelle Blog #4: C-Clip Axle...

Hope that helps. It's a pain either way. Wait till you do the drum wheel cylinders!!

[gcburdic]

Originally Posted by beautimus

when you drain the axel look for metal shavings and stuff in the bottom of the housing. if there are no big particles, your in good shape. this could be a blessing in disguise.

beautimus....at the end of my build in Nov 08, I finally changed rear lube in it and changed the gasket...everything looked good then, but now that I have run this truck about 650 miles, it'll be a good checkup...thanks

Originally Posted by d10s69c10

I hoped that is some help.

I appreciate you taking the time to answer each question....By the way, that Powertrax unit is an easy install...or so the web site says!!!...thanks again for you time!

Originally Posted by Tx Firefighter

To install the seal, you can use a piece of 2x4 wood and a hammer to gently seat it into place.

Be sure and check your differential breather to make sure it is open. Blow through the hose and make sure it isn't stopped up. When they stop up, heat from driving will cause pressure to build up in the differential and force it out of a seal, causing a leak.

TXFF....I was hoping a 2x4 would work...I definitely have that in my tool arsenal!!....I really appreciate the info about the breather, although it is rather new, it doesn't mean it hasn't clogged up...Thanks for this valuable reminder!!!

Originally Posted by Sammy

Took about 30 min a axle and two beers before I was finished. Some of the better carquests can remove the bearings for you and install knew ones. Just a thought if you took the axles in when you got the parts.

That's what I'm talking about Sammy....I work in beer time...so 2 beers to get through this.....but I'm a novice, so Maybe it'll be 4 and 1.5 hrs!!!
Thanks for you input!

Originally Posted by Legolas894

All good stuff here. I put my seals on with a hockey puck and a hammer. Just get them even first.
Hope that helps. It's a pain either way. Wait till you do the drum wheel cylinders!!

I appreciate the video...it's very helpful to see the pieces so I know I at least took the right ones out!!!
Luckily the drum wheel cylinders were replaced when we rebuilt the drums....so hopefully I won't have to do those for awhile!!!


I anticipate doing a step by step when I get on this SOON, so it'll help other as well....Thanks everyone for your input again...this board and its members ROCK!!!!

[lilred67]

i have replaced two sets of axle seals lately, and bought gm seals from dealer. i figured if the original one's lasted 40+ yrs. i would use the gm seals again. no leaks