Rear Axle Seal Leaking - Causes?

[gtobey]

Upon trying to rotate my tires at 86k miles on my 2006 3500 SRW Mega Cab, I removed the rear wheel from the rear passenger side, and axle grease was oozing out around 3 of the wheel studs.



For some reason I found that odd, so I began disassembling stuff to investigate. I removed the 2 caliper mounting bolts and wired it to the leaf spring out of the way. Next, I pulled the rotor off, and found the oil all over the parking brake shoes.

Then upon closer investigation, I found a nick on the hub, which I know I did not do as I could see where something had been rubbing the vertical face of the steel that protruded from the impact to the hub.

I don't have the new seal to see exactly where it rides on the hub, but I was wondering if anyone could tell me if that might possibly have been the cause of the leak. ???



I wasn't quite ready to do the rear brakes yet, but I guess I am now! Got to wait on parts (seals and parking brake shoes) as no one in town has all the pieces, so I was just wondering what experiences anyone else might have had. Thanks!

 

[6speed]

Were that nick is, I wouldn't be to worried as the seal will be farther up on the housing. I had one do it here a while back. But I didn't have nick thou. Those rotors are heavy when you put them back on. Just be careful as not to let it hang until you can get that outer bearing back in.

 

[Joseph Donnelly]

Install the new seal where it will ride on the smooth surface of the spindle. Replace the brake shoes as you can't get all the lube out of them. Use brake cleaner to clean the brake hardware etc.

 

[gtobey]

Thanks for the replies folks, and good to hear from you Joe! Hope you're doing well!



Since I replaced my front brakes about a month ago using cryo-treated power slot rotors, exchange calipers and Wagner Thermo Quiet Severe Duty Pads, I have decided that I will give the rear brakes a similar treatment. I plan on replacing the rotors, exchanging calipers and putting new Wagner Thermo Quiet pads, new brake hardware, new emergency brake shoes, will clean everything to the max, then pressure bleed the brakes once again...



Of course, I don't want to have to go through this again because the seal leaked again, and waste more $$$, I will first carefully install the drive hub with the inner wheel seal and bearing over the spindle and then install the outer wheel bearing and torque the spindle nut. Then I can put the new rotors on after all that is installed. I just thought it odd that the spindle/hub had a ding on it apparently from new, and since I didn't have a true concept of where the sealing surface was for the seal, I wondered what was rubbing on that ding as the picture showed.



I noticed that on the driver's side, there was a tell tale ring around the largest diameter of the spindle where the seal lip appeared to be leaving it's mark. On the passenger side, there was no mark where the seal lip was rubbing on the spindle in the same place as the picture shows. I thought that to be a bit odd also. My Ram Service Manual (CD) spoke about prying the hub bearing seal from the back of the hub. Mine did not stay on the spindle, it came off with the seal, and I didn't get to remove the seals last night to see how they were made. They didn't look like a standard single or double lipped wheel seal.

 

[rscurtis]

While you're in there, verify that the axle vent is not restricted.

 

[Wingate]

While you're in there, verify that the axle vent is not restricted.

X2... ! And verify the e brake cable is fully releasing the brake when applied... excessive heat can cook a seal

 

[BDaugherty]

3rd gens have unitized rear hub seals so that nick shouldn't have any effect on sealing. most likely either the wheel bearings got a little too loose or the seal was just worn out.

 

[mwilson]

One of the very few warranty failures that I experienced with the '06 was a rear wheel seal at about 15,000 miles.



Tech (who I know fairly well) came out to see after the seal replacement and started to give me Hell, said that I had overfilled the rear end. I told him that the dealership had done the PDI, not me so if anyone overfilled it the choices were the factory or the dealership.



He took me out and showed me the horizontal line about a 1/2" or so under the fill plug and informed me that was the maximum fill line, not the bottom of the fill plug hole as is the case with just about any other brand of driving axle.

I have heeded that advice while doing fluid changes and at 130,000 miles the wheel seals are still dry as a bone.



I don't think that I can get you a clear picture of that line as the diff cover has crusty rust on it but see if your truck has that line. If so then that is the maximum fluid level.



Mike.

 

[gtobey]

Thanks to all for the great advice! I will check all those things this evening. My parts are arriving today, so I hope to start back together tonight. I will check the vent tube, emergency brake cable (while I am replacing the emergency brake shoes).



I did have time last evening to start cleaning up stuff, (waiting on parts to arrive), and found out a little about the seal at lunch today here at work doing more cleaning. It seems that the seal is a (unitized) two piece unit much like the crankshaft seals used on Isuzu Industrial Diesel Engines that we sell. It has a wear sleeve part that goes over the spindle on the end of the axle, and fits all the way back to the shoulder (where the nick is shown in the previous pictures). There is a rubber coating on the inside diameter of that wear sleeve to seal against the spindle o. d. , and a rubber coating on the back of that wear sleeve where it contacts that shoulder. That is why the genuine service manual stated that the sleeve had to be pried off of the spindle after you pull off the axle hub assembly!

I may put a little Permatex Hi-Tack on the spindle where the sleeve part of the seal finally rests to help prevent oil leaking between the spindle and sleeve. When I looked at the inside lip of the sleeve of the seal on the side that was leaking, it appeared that oil had been leaking by the sleeve. Also, the seal did not offer much resistance to pulling the entire hub unit assembly off of the spindle which I thought to be a bit odd... This is a picture of the old seal/sleeve from the leaky side.

Thanks for the suggestion on the oil level in the diff. I had noticed that when I changed the fluid @ 15K miles, and fashioned a "dipstick" from a nylon wire tie by bending the tip into a 90 degree and cutting it off at the right length so it will rest on the threads of the plug hole and give me a good reading for the oil to come right up to the max oil level line on the cover. Makes it easy to fill it up to the right place. There was too much oil in mine right from the dealer, and I think that is why the oil was seeping from the pinion seal on the front diff soon after I purchased the truck. No problem since.



Looking at the wheel bearings, they appear as if they were turning on the spindle just a bit, but there wasn't an indication of that on the surface of the spindle. The inside of the cone is polished as if they have been spinning, so they may have been a little loose, which may also have caused the oil leaking from the seal. I will torque the spindle nut up to 22 lbs. ft. as specs show, and back it off about the 30 degrees they recommend to line up the key slot to the slot on the spindle nut. Then I can compare to see if it falls into the same slot on the nut as it was before, because I marked the original slot on the nut where it aligned with the slot on the spindle. I'll check that out when I go back together tonight...



Here is the part number for the new seals I am putting in, 05086773AB.



Thanks so much, and I'll post the results of what I find...

 

[mwilson]

On large trucks and trailers using two piece seals it is a common practice to apply a VERY small amount of RTV sealant to the seal surface on the spindle if there are any imperfections or grooves present. Just smooth it with your finger to create a thin coating before installing the seal and hub assembly.



I did a couple of trailer wheel seals over at my expense before learning that lesson... .....







The two piece design seal is much gentler on spindles ( only exception being when the seal sticks and becomes a one piece seal, that will mark up the spindle in a hurry) and is the preferred design for trucks and trailers that accumulate hundreds of thousands of miles.

Seals have to be better now as the drums on Hub Piloted truck wheels can be removed without disturbing the hub so the seals don't get changed like they did back in the day when the entire unit had to be removed for a brake job.

Gear oil can leach out through a very small imperfection without something to block it.



Mike.

 

[sag2]

Remember a tapered roller bearing will last much longer more loose than too tight.

 

[gtobey]

Remember a tapered roller bearing will last much longer more loose than too tight.

Thanks so much, sag2, and you are exactly right. Just snug enough to remove any play, but do not even think of snugging it up! Give 'em room to turn... . but not wobble. Lots of different sayings all mean the same thing, including do it right the first time.



I got rained out last night, 60mph winds, hail, about 1. 5" of rain in about an hour, even bent my aluminum 25' flagpole! Just couldn't bring myself to try to install the hubs while someone sprayed me in the face with a garden hose in front of a couple of 6' diameter ventilation fans. Maybe tonight will be more calm...



I'll post my findings here when I get the thing done.

 

[gtobey]

TODAY'S UPDATE: Well, I got the passenger side put back together last night, (no rain, thankfully!). Before I left work, I called my friendly Snap-On man, and obtained a KD Tools hub nut socket number KD2770.

The book says that it fits the Dana 44's, so that will be good. But it also fits the 11-1/2 American Axle, and that's what counts.

I torqued it to the 22 lbs. ft. that they specified, while turning the hub to keep the bearings seated properly in the hub, and here is what the nut looked like on the spindle after being torqued.

Notice the punch mark I made on the nut where the keyway aligned up originally (before I removed it from the spindle). In this way, I could tell if I had everything seated where it was supposed to be when I put it all back together. It is about 30 degrees clockwise of the keyway, which is where it should be once the nut is torqued. The manual tells us to back off of the nut about 30 degrees in order to line up the keyways, then install the key and retaining ring. That provides the proper end play for the bearings as you folks mentioned. I checked it out with the left hub, by not installing the rear seal, and also with no grease in the bearings so that it would be easy to feel and check for end play. When I aligned the keyways, the nut almost went "free" from contact upon the outside wheel bearing cone. It just held it in place such that there was no discernible play by hand, and the hub would spin very freely if you gave it a whirl. I couldn't ask for it to be any better!

So then I could pack the bearings with grease, install the new axle hub seal, and then I put a thin film, not a "bead", of RTV Silicone onto the shoulder where the seal fits. It may tend to lubricate the rubber on the inside of the wear sleeve when it installs as well as provide a positive seal against gear lube leaking between the sleeve and the axle. When putting the film of RTV silicone on that shoulder, I stayed away from the front edge of the shoulder to help prevent silicone from getting into the hub or bearings. As the hub was being installed, the seal slid back onto that surface while you tightened the spindle nut, and would tend to push the excess silicone back away from the inside of the hub.



After the hub assembly went on properly and felt great, I carefully and slowly installed the axle through the hub and into the splines of the differential with a new flange gasket, and torqued the 8 bolts to 95 lbs. ft. , installed the new rotor while checking the new parking brake shoes for proper adjustment. I had to adjust the parking brake by turning the adjuster at the bottom of the shoes. Then I checked the total disc "runout" and made adjustments by indexing the new rotor in different places on the hub for the lowest total variation. Once that was done, I mounted the caliper bracket, new brake pads, the caliper, and connected the brake hose. Here's what it looked like.

Now for tonight, since I am doing this outside, I hope there's no rain. There's a bobcat in one garage that also needs fixing, and a '55 Bel Air in the other garage getting worked on, so I am stuck outside. Well, that being said, it's now on to the driver's side.



Thanks to all for helping! I am hoping to achieve long-term success so that I won't have to touch this until I need rear pads again.

 

[Prairie Dog]

Looks like a Bosch disc? They are top notch.

 

[gtobey]

You are a winner!

Looks like a Bosch disc? They are top notch.

Yes sir, you are exactly right! Great recognition! I wanted the Power Slot Cryos, which I had just put on the front about 2 months ago, but thought I couldn't wait on them. Turns out with the problems I encountered, I probably could have waited. But, I read that the Bosch QuietCast Rotors were really good, so I decided to give them a try. They look really nice, great finish on them, and they are very, very true. These 2 have '0' runout on their own, (mounted on our lathe only to check them for runout). Measuring the runout of the hubs, they were not as true, but I can't do anything about them at this point. I was able to index the rotor on the passenger rear side to bring the runout at the outside edge of the disk to . 005". I would've liked it to be 0. 000" like the front ones, but I'll take that, and if sometime later the brake pedal pulsates, I'll know what to address, and where it is... Thanks for your help!:-laf

 

[rscurtis]

There is no need to pack the bearings on this axle. Simply jack up the other side of the truck, and when you see the oil heading down the axle tube, install the axle and let it sit for a while until the bearing cavity fills with oil. There is no harm in what you did, just extra work. I've done this on other floaters, including my signature truck when I had to remove the axles to check and adjust the preload on the pinion bearings to help get rid of a deceleration whine which the truck had when new. The only truck I ever worked on with dry hubs was a '63 International C120 with the IH-built rear axle. The bearing retaining nuts were equipped with a face seal to keep the axle lube out of the bearing area.

 

[gtobey]

There is no need to pack the bearings on this axle. Simply jack up the other side of the truck, and when you see the oil heading down the axle tube, install the axle and let it sit for a while until the bearing cavity fills with oil. There is no harm in what you did, just extra work. I've done this on other floaters, including my signature truck when I had to remove the axles to check and adjust the preload on the pinion bearings to help get rid of a deceleration whine which the truck had when new. The only truck I ever worked on with dry hubs was a '63 International C120 with the IH-built rear axle. The bearing retaining nuts were equipped with a face seal to keep the axle lube out of the bearing area.

Thanks so much, rscurtis, for the kind advice. I know when we used to rebuild the axles on IH 50-ton rock haulers when I worked on heavy equipment, we never "greased" the bearings, just dipped them in the axle grease, and installed them. I have a bearing packer that I use with my grease gun, so I gave them a few shots of synthetic grease until it came through the rollers, and put 'em in. I think they'll be OK. I seem to remember when I change the diff fluid @ 15K miles, there was some small globs of something that resembled "white grease" that came out of the hogshead. I'll bet they packed the brgs with a white grease, similar to engine assembly lube, or something like Lubriplate when they originally installed them. I'll probably see my grease in globs coming out the next time I change it. The big old IH trucks were something else, weren't they?

 

[gtobey]

So close, but yet so far. Last night about 11pm, (2nd night in a row without major thunderstorms; we must be in a drought again!) I was almost ready to pressure bleed the brake system and test drive the truck. But victory was snatched up and bitten by the jaws of defeat! Maybe I fell victim to "haste makes waste", got in a hurry, or was just too trusting of Wagner products, but Wagner let me down. Here is what I was installing on the driver's side rear wheel:

I don't know who "CS" is, but they are either not much of an inspector or fell asleep at the switch on this one. I could not stop a brake fluid leak at the connection to the caliper where the copper washer seats onto the caliper under the banjo end of the brake hose. It would just seep out and drip off of the caliper at a rate of 1 drop in 15-20 seconds. I had torqued the bolt to the recommended 245 lbs. in. , and felt it with a 15mm wrench to insure it was snug. (I use Snap-on digital tech wrenches, so I didn't really think it was not torqued properly)



So, out came the banjo bolt, and off came the line. I got my magnifying glass to look at the caliper and the copper washer, and found this:

If you look at the 3 o'clock position of the hole in the caliper, you will see a slight imperfection, but most of all, it appears that they did not reface the seat for the washer below the banjo fitting. Most every exchange caliper I put on from Wagner has been resurfaced with new grooves around the hole to provide a good positive sealing surface for the copper washer. In this case, I missed inspecting it before I installed it (guilty as charged!), and they missed fixing it properly (also guilty!). Two wrongs could not make that one right! It is a very small nick in the surface, but this proves it doesn't take much... . I hope this will serve to remind me to check these things before I install them in the future, and not just assume that they did their job that we're paying them for... (WHY would I ever expect it to work the first time, all the time anyway????)



I need the truck on Saturday, so it's one more late night in the trenches, (5th one in a week) as I found a Duralast Exchange caliper from AutoZone this morning, (reman'd by A-1 Cardone) And it looks good on the washer sealing area, even with new grooves machined into the washer sealing surface. We'll find out in a few hours... .

 

[gtobey]

Well, I finished putting the truck back together Saturday morning the 20th, and barely had time to get the emergency brake adjusted a bit before I had to take it on a trip. I did use RTV red where the internal part of the seal fit over the spindle to help it slip over the spindle, and also to finally provide additional sealing material to help the seal stick to the spindle and prevent grease from seeping out.



Luckily, after pressure bleeding the brake system, the new rear brakes worked great, and the rear axle bearings did not make any noise. So off we went on a trip of about 1500 miles. After repairing things or working on something, I usually like to at least test things out a bit before going on that sort of long trip, but I didn't have the luxury of time to do it that way.



For the first two hours on the road, I kept plenty of distance between vehicles, and very cautiously applied the brakes. I worked to keep from slamming them on for the first few hundred miles by coasting, and anticipating stops. And now that the trip is done, everything seems to be working fine once again, no visible gear lube leaks, and the new brakes are smooth, quiet, and seem to be more powerful than the OEM brakes were. I am both glad and sad. Glad that I found the problem before the trip, and that I persisted and finally got it done despite the delay caused by the defective caliper, but sad that the seal failed causing all the work in a rush.



So far, and I know it's too early yet to draw many conclusions, I am very satisfied with the Bosch QuietCast Rotors. They were very true (as checked with my dial indicator after mounting to the hub), and I do like the finish on them which is to help prevent rust. The silver color hasn't seemed to change since I got the brakes warm. (I didn't take my infrared thermometer gun with me to tell how hot the rotors were actually getting. I will check them by this weekend. )



Thanks to all for your kind advice, tips, and knowledge! It is greatly appreciated, and I'm certain that it helped me toward getting the job done quickly and correctly.