Community
Buy / Sell
Bronco Tech
Fuel Tank Access Plate
3 Arm Wiper Setup
Fix Motor Mount
Roll Cage Braces
Throttle Body 65mm
Wheel Alignment
Heat Riser Replacement
Vent Window Repair
Center Console Mount
Straighten Bumper
Ford 6R80 6 spd
More Tech...
3 Arm Wiper Setup
Fix Motor Mount
Roll Cage Braces
Throttle Body 65mm
Wheel Alignment
Heat Riser Replacement
Vent Window Repair
Center Console Mount
Straighten Bumper
Ford 6R80 6 spd
More Tech...
-
Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!If you have problems registering or can't log into your account, please contact Admin.
Rear axle seal
- Thread starter turbotim2
- Start date
NC-Fordguy
Bronco Guru
Could be it was seated incorrectly.
Make sure it's not over filled
Make sure it is not brake fluid. Good luck
Are you running factory axle bearings with seals pressed into the tube ends or something else? There are a plethora of axle bearing options nowadays that do not require the internal oil seal, but do usually benefit from a thin layer of RTV on the outer bearing race to take care of irregularities and imperfections in the housing ends.
The SET20 tapered roller bearings use an external oil seal, which also can be prone to leaking, especially if/when removed and reinstalled in my experience.
The SET20 tapered roller bearings use an external oil seal, which also can be prone to leaking, especially if/when removed and reinstalled in my experience.
NC-Fordguy
Bronco Guru
Should be easy to locate exactly where the problem lies. On stock applications I usually find the seal wasn't driven in correctly or the circular spring on the seal has popped off.
Sometimes there is a deep groove on the axle shaft that has been caused by years and years of grime and dirt where it meets the seal which is another source for a leak.
My experience with this issue is not all seals are equal. I found some seals have a bigger I.D. where the axles slips through. National brand had the tightest seal which is good and bad as tighter means more friction and a quicker groove on the axle.
You might try polishing the axle where the seal rides. Then use the tighter fitting seal.
Speedie sleeving the axle is also an option if the axle is pitted and or grooved
Did you put put a little oil on the seal before you slid the axles in? If not dry rubber on dry axle can cause damage to the seal.
Is the axle housing (where the bearing slides in) damaged? Mine was damages from an old bearing failure and was SO bad, the bearing over time "oblonged" the cup thus allowing the axle bearing and axle to move up and deform the seal. I replaced my housing cups and that fixed the issue.
Tim
You might try polishing the axle where the seal rides. Then use the tighter fitting seal.
Speedie sleeving the axle is also an option if the axle is pitted and or grooved
Did you put put a little oil on the seal before you slid the axles in? If not dry rubber on dry axle can cause damage to the seal.
Is the axle housing (where the bearing slides in) damaged? Mine was damages from an old bearing failure and was SO bad, the bearing over time "oblonged" the cup thus allowing the axle bearing and axle to move up and deform the seal. I replaced my housing cups and that fixed the issue.
Tim
Crawdad
Bronco Guru
- Joined
- Feb 16, 2011
- Messages
- 3,635
Tim,
I've been trying to overt myself from having the issue you are having. My axle shaft have new bearings as well, but I've been informed that they crap due to the groove you can see above the bearing. There are repair sleeves out there but none out there fit a shaft that is roughly 1.535" dia. The closest repair sleeve I've seen is 1.520" dia. With that I'm hoping a lil 200 degree heat and a hydraulic press will slide on with some RTV. I have not done this yet as I need to buy the bigger repair sleeves, I originally purchased 1.505" dia. Next time I will measure.
Matt
I've been trying to overt myself from having the issue you are having. My axle shaft have new bearings as well, but I've been informed that they crap due to the groove you can see above the bearing. There are repair sleeves out there but none out there fit a shaft that is roughly 1.535" dia. The closest repair sleeve I've seen is 1.520" dia. With that I'm hoping a lil 200 degree heat and a hydraulic press will slide on with some RTV. I have not done this yet as I need to buy the bigger repair sleeves, I originally purchased 1.505" dia. Next time I will measure.
Matt
Attachments
I have not sleeved an axle myself but I'm 100% positive others have but not sure what size they used. I recall seeing it posted a few times.....
I did sleeve a pinion yoke many years back. I went to NAPA and they measured, pulled out a book and gave me a sleeve. Worked great.
I've since moved to 31 spline axles and SET20 bearings/seals
Tim
I did sleeve a pinion yoke many years back. I went to NAPA and they measured, pulled out a book and gave me a sleeve. Worked great.
I've since moved to 31 spline axles and SET20 bearings/seals
Tim
Brent13
Sr. Member
I have the same shim under my springs. I still filled my 9" until it started to flow out the fill port. I replaced my axles seal when I did the ring and pinion. Mine is not leaking, so not sure what to think, still feel you should fill until at the bottom of the fill port.
I had a ford truck years ago that kept leaking through the seals and after changing them 2 times finally found out it was the vent was plugged. Unplugged it and didn't leak since. Ken
vintage bronco
Sr. Member
- Joined
- Feb 8, 2010
- Messages
- 850
Bingo ! check the breather and hose.
blubuckaroo
Grease Monkey
This^
Overfilling the diff can make it leak.
Sure, we all want to think those seals should hold oil in, but they're really only designed to hold dirt out and oil splash in.
If you cold fill the diff to the drool point, you've overfilled it. The oil expands when heated. It should be pinky deep when cold, and drool out when hot.
- Joined
- Nov 3, 2003
- Messages
- 51,619
I see something that looks off, but I can't say that from any engineering standpoint. Just that it looks wrong.
Your axle shaft is definitely worn Tim. That part is pretty obvious. But it looks like the real wear is where the seal used to ride, and now you can see the black mark just outboard of the wear spot that looks like the seal was riding there.
So far so good. But why in just 100 miles is there any black being left on the shaft in the first place?
I can't say it's wrong, but I can say I've never seen that before.
And looking at the seal itself, why in the heck has it got a hex-shaped inner lip with those hard corner transitions inside the main lip? Never seen that before either.
Looks to me like the seal was either:
1. Too small
2. Softer material that's breaking down already
3. Or has somehow become burned and is loosing it's life right in front of our eyes.
That last likely related to the seal being too tight anyway, so that's really only two things.
But an important aspect of 9" outer seal leaks is to determine whether the leak is at the business end of the seal, on the shaft. Or if it's leaking around the perimeter where many new seals leak from small scratches and gouges in the housing.
If it's leaking from around the outer edge, all you have to do is clean it, dry it, and goop it up with silicone sealer.
If it's the axle shaft edge that's leaking, I would personally change it out for a new one since you have it apart and the current seal looks compromised.
But no matter what, I would certainly smooth down the shaft surface the best you can. Some 400 grit or finer sandpaper is your friend here.
Get the shaft smooth, and trial fit the seal over the surface to see how it feels.
Good luck.
Paul
Your axle shaft is definitely worn Tim. That part is pretty obvious. But it looks like the real wear is where the seal used to ride, and now you can see the black mark just outboard of the wear spot that looks like the seal was riding there.
So far so good. But why in just 100 miles is there any black being left on the shaft in the first place?
I can't say it's wrong, but I can say I've never seen that before.
And looking at the seal itself, why in the heck has it got a hex-shaped inner lip with those hard corner transitions inside the main lip? Never seen that before either.
Looks to me like the seal was either:
1. Too small
2. Softer material that's breaking down already
3. Or has somehow become burned and is loosing it's life right in front of our eyes.
That last likely related to the seal being too tight anyway, so that's really only two things.
But an important aspect of 9" outer seal leaks is to determine whether the leak is at the business end of the seal, on the shaft. Or if it's leaking around the perimeter where many new seals leak from small scratches and gouges in the housing.
If it's leaking from around the outer edge, all you have to do is clean it, dry it, and goop it up with silicone sealer.
If it's the axle shaft edge that's leaking, I would personally change it out for a new one since you have it apart and the current seal looks compromised.
But no matter what, I would certainly smooth down the shaft surface the best you can. Some 400 grit or finer sandpaper is your friend here.
Get the shaft smooth, and trial fit the seal over the surface to see how it feels.
Good luck.
Paul
Yes
fluid needs to be 1/2 below the fill hole .
fluid needs to be 1/2 below the fill hole .
Crawdad
Bronco Guru
- Joined
- Feb 16, 2011
- Messages
- 3,635
Tiko,
Is there a specific amount of fluid that goes in the rear axle housing? 2qts? 5 qts? 7.5qt?
From what I remember it's around 2 I not sure exactly
