Gear lube in Brakes!!!

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str12-340

str12-340

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Below are a couple pictures. The axle had a whole new kit installed on the axle about 4,000 miles ago (bearing, seals gaskets, adjuster) all functions well but lube seems to be seeping out between the adjuster threads and the axle (see photos). I think the shop damaged the outer seal when they installed the kit on the axle. What do you think? what else could it be? The gaskets between the adjuster flange and the backing plate are perfectly dry.
 

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Just install new seals,,,,$hit happens or stuff wears out...buy some brake cleaner, clean up and slap in some new seals and go...no biggie
 
Pull the axle, get a new set of seals and the pressed on retainer, take it to a shop and get the retainer off, get the new stuff pressed on, reinstall the axles, replace the brake shoes on both sides... yeah no biggie. just a day of my time and 100 bucks from a problem I think was caused by a shop that does nothing but rear end and axle work...
 
If it is leaking rear end oil as in 75-140. You need to replace the inner axle seals. The original taper bearings are packed in wheel bearing grease.
 
Did they use cheap seals, or is the axle shaft pitted/ grooved ,where that seal rides? Something else to look at, besides idiotic installation
Edit: Sarge,,probably nailed it..
 
SGBARRACUDA said:
If it is leaking rear end oil as in 75-140. You need to replace the inner axle seals. The original taper bearings are packed in wheel bearing grease.
Click to expand...
You may grease the bearings initially but they are lubricated by the rear end lube through the axle tubes.
 
No they're not lubed by gear oil.
There's an inner and outer seal per side.

If the bearings/axles haven't been adjusted properly, too much axle play will force the axle 'up' slightly, sometimes enough to let some gearlube pass through the seal.
 
toolmanmike said:
You may grease the bearings initially but they are lubricated by the rear end lube through the axle tubes.
Click to expand...

The seals are inside the tube, before the bearings. If the inner seal isn't functioning, it will leak as shown. It will also wash the wheel bearing grease out, and the bearing will fail, also. A brake drum installed backwards will gain you balance, and reduce the possibility of damaging the new seal when you install the axle shaft.
 
BigBlockMopar said:
No they're not lubed by gear oil.
There's an inner and outer seal per side.
Looks like I better take mine apart and pack the bearings with grease then. I have never done it and I have had the axles out. There is no information in the service manual about repacking rear wheel bearings just a note to apply grease when assembling. That's a grey area in the manual. I must be thinking of a C clip style axle. I think they just have a outer seal.
Click to expand...
 
Correct. Other style later rearaxles (GM/FORD, perhaps Mopar too?) have straight roller bearings riding directly on the axles themselves.
These are lubed only by the gearoil in the rear axle.
 
If the preload on your axle bearings is not adjusted properly the axle may have worn or stretched your inner seal. They are tapered roller bearings just like the front of most older cars. They require grease packing not gear oil. The inner seal is what is allowing the lube into the brakes. Make sure your housing is not over filled and the housing vent is functioning as well.
 
Also make sure the axle tube vent is working properly, if the breather is stopped up, the pressure created in the rear will push oil past the seals or blow the seals out as its more commonly known as.
 
Something else occurred to me. If you are running a powerlock type diff that requires the buttons through the center for axle bearing preload and they are missing or pulled out with the axles and dropped in the housing this will happen. It sure looks like your adjuster is way far in. Most usually have some thread showing. You should not be able to pull or push your axles in or out any when installed.
 
What about "Green Bearings" ? (That's another story , discussion, and thread.)
 
So here's today's installment of the drama:
I pulled the axle on the side that was leaking (checked the play in the axle first and it was fine - and on both sides, so I know the pins in the Sure Grip are in place). Inspection of the bearing shows it is fine. I talked to the guys at Randy's Ring and Pinion and they confirmed a few things I saw folks offer here - the differential lube should never reach the axle bearings except in minute amounts. The seal in the housing is what separates the diff lube from the bearings. I KNOW!!! - how are the bearings in my other two Darts that have been untouched for 20 years or more working fine with no service!?!? I clean and repack the front wheel bearing every year or so.

According to the RR&P guys, even though the seal feels pliable and shows no damage, that doesn't mean it's OK. You can't feel or see if the seal has become out of round or worn so that lube slips through. So today I replaced the seal, repacked the axle bearing, replaced the gaskets and put it all back together following the service manual procedure for axle end play. I replaced the soaked brake shoes, and that meant replacing the other side shoes to match, adjusted them all up. Tomorrow I need to drive 50 miles or so, put 'er up on the lift, say a few prayers and pull that drum and see if the diff lube stayed where it belongs. Wish me luck!!!

Thanks to everyone that contributed here, even after 35 years of Darts with 8&3/4 rears, I learned some new stuff! I'll let you know if the fix worked...
 
I use green bearings in my drag car (8&3/4) - less drag and longevity isn't really an issue. Tapered Timken bearings in all my street cars - they last and last and last...
 
[QUOTE
Thanks to everyone that contributed here, even after 35 years of Darts with 8&3/4 rears, I learned some new stuff! I'll let you know if the fix worked...[/QUOTE]

X2
 
str12-340 said:
I use green bearings in my drag car (8&3/4) - less drag and longevity isn't really an issue. Tapered Timken bearings in all my street cars - they last and last and last...
Click to expand...

I run green bearings in my demon, from what i understand its a great way to go, but everyone has theyre preffered brand
 
You may want to google articles related to the 'short fiber grease' that is referred to in the Dodge FSM's for rear axle bearing assembly; it apparently is not just any wheel bearing grease, or what you would put into a grease gun. It is a certain sodium soap based grease.

Why does it last? Well some small amounts of gear oil WILL get past the inner seal from time to time. I suspect it keeps the whole area around the bearings well lubed and supplements the initial grease load. Take apart an old 8-3/4" axle and see how much grease is still in there.
 
This was always my understanding. MT

Why does it last? Well some small amounts of gear oil WILL get past the inner seal from time to time. I suspect it keeps the whole area around the bearings well lubed and supplements the initial grease load. Take apart an old 8-3/4" axle and see how much grease is still in there.
Click to expand...
 
The splines on the axle can also cut the seal as its slid in, you can put paper over the end as you slide the axle through the seal to prevent this also. I just replaced one on my aspen with an 8 3/4 last summer, the seals are not as cheap as they used to be.
 
BigBlockMopar said:
Correct. Other style later rearaxles (GM/FORD, perhaps Mopar too?) have straight roller bearings riding directly on the axles themselves.
These are lubed only by the gearoil in the rear axle.
Click to expand...
't recall one with rollers riding on the shaft; all I have used/seen have an inner and outer race assembled bearing: the inner race is what gets lightly pressed onto the axle shaft and/or retained by a press-on collar. Interesting that the early 7.25" had an inner seal as well as any seal on the bearing assy, and grease was applied on the outside of the bearing assy as a rust preventative per the FSM.
 
Well I drove the Dart around for 50 miles today - speeds 30-60mph, side loaded in turns and hard acceleration on the staightaways. Pulled it in , pulled the drum and.....NO DIFF LUBE! I hope this is the last of this gremlin.

Now a related question - to get gaskets, seals etc. I broke open a "bearing accessory package" NAPA number A7-RK ( other side is a A7-LK) This one was made by a company called SKF. The kit includes a new adjuster, or retainer, metal shim and foam gaskets, two seals. I used to keep a set on the shelf just in case. This one was bought in 2005. So I go to NAPA - no such number. I get on line and look for half an hour and can't find it. Does anybody have a source for these things???
 
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