8 3/4 Axel external seal leak repair

HS 69 Charger

Member
Local time
9:52 AM
Joined
Apr 5, 2022
Messages
19
Reaction score
6
Location
Overland Park, KS
In the process of upgrading my differential back to sure-grip, I pulled the axels to have the seals and bearings replaced (they were original AND there was a Axel Bearing noise). Now that everything is out and cleaned it was apparent the outer axel seal at the "adjuster" (passenger side) was leaking. Additionally, previously, my Brake Wheel Cylinder was leaking which of course drips right onto the external axel seal. I am sure one compounded the other. On inspection of the bearing it has a slight visible rust in the bearing and is not as smooth and easy to spin as the Drivers side axel. But no real apparent damage to the Axel.
Much more apparent is the muck and residue in the Axel Housing after removing the axel. I popped out the seal. Good news is on the inside of the seal the Gear Oil appears clean and undisturbed. But on the external side of the seal it is covered with muck (gritty and rust colored). I did also remove the backing plate so then cleaned the Axel Housing Face and internal back to the seal. The pictures below are the result. They cleaned up reasonable well but there is evidence of pitting on the surface.
So here is the question. The Seal area appears to be fine and should slide in ok (of course the seal is really on the Axel. So since the rest of the tube is neither a seal or a bearing surface is the pitting a problem?
After cleaning I have coated with wheel bearing grease just to keep any residual surface rust/deteriation from continuing. Is there a problem with going forward with the seal replacement and then axel re-Assembly?
Is there any surface prep I should additionally do before sealing it all up?

Both Axel Faces cleaned up enough to leave a complete smooth surface ring for sealing.
A picture is worth a thousand words so here are the pics.
Passenger Side
upload_2022-5-3_19-39-56.jpeg

upload_2022-5-3_19-40-10.jpeg


As a comparison here is the Drivers Side
upload_2022-5-3_19-41-58.jpeg

upload_2022-5-3_19-42-15.jpeg
 

pnora

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Apr 21, 2020
Messages
3,068
Reaction score
3,327
Location
Ishpeming, Mi.
1-Remove and clean the vent.
2-Replace both axle bearings. I pack them with grease.
3-Replace both inner and outer axle seals.
4-Replace both seals backing plate to tube and bearing flange to backing plate.
5-Set the axle end play.
6-I also would change the gear oil.
 

493 Mike

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Dec 25, 2011
Messages
4,458
Reaction score
4,981
Location
White Cloud, MI
The inner seal usually comes with a type of sealant on the OD. That should be enough for the drivers side but, I would put a layer of silicone sealant in the pitted seal area to retain the gear lube. The outer seal is merely a dust seal and should be dry.
Mike
 

Demonic

Well-Known Member
Local time
10:52 AM
Joined
Jun 5, 2017
Messages
1,761
Reaction score
1,585
Location
Maryland
Everyone forgets about the outer seal. If you have access to a press, doing bearings and outer seals yourself isn't hard.
 

dvw

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Feb 16, 2010
Messages
6,846
Reaction score
10,782
Location
waterford mi
No real reason to do outer seals or bearings if they're not noisy. The inner seal is what keeps the gear oil out of the brakes. If there's a gear oil lek they need to be replaced. They are good iinsurance. The bearing should be packed with grease. The outer seal under the retainer is a grease seal. They seldom leak. The fiber seal between the backing plate and housing is a dust seal. I don't even use them as the drum isn't sealed anyway.
Doug
 

pnora

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Apr 21, 2020
Messages
3,068
Reaction score
3,327
Location
Ishpeming, Mi.
No real reason to do outer seals or bearings if they're not noisy. The inner seal is what keeps the gear oil out of the brakes. If there's a gear oil lek they need to be replaced. They are good iinsurance. The bearing should be packed with grease. The outer seal under the retainer is a grease seal. They seldom leak. The fiber seal between the backing plate and housing is a dust seal. I don't even use them as the drum isn't sealed anyway.
Doug
He claims they are noisy, original, and has a leak of some sort.
 

HS 69 Charger

Member
Local time
9:52 AM
Joined
Apr 5, 2022
Messages
19
Reaction score
6
Location
Overland Park, KS
Thanks to all the great replies. I don't have a press so am using a shop to do the upgrade on my Diff (resurrecting my original SureGrip as in replacement), I am having them do the complete rebuild on the Axels. Everything listed on "pnora's" response is what I am having them do.
On the axel housing itself, I already have new gaskets for Backing Plate to Housing (coated metal) and then from Axel plate to Backing plate (foam).
I will add the Two additions noted in your posts:
@pnora: step 1. Remove and Clean the Vent. I don't know what this is so could use some guidance.
@493 Mike: Add a bead of sealant on the passenger side due to the pitting. Perfect I will do this. I expect I should add a bead right up next to that second shoulder inside the housing so when I press in the seal it butts right up to it??? or press in the seal and then add to the face/housing joint on external side or just a thin layer on the housing surface where the seal will press in.
One extra question on the gasket between Backing plate and axel housing. There is a ring ridge on the gasket. Should it be facing in or out.

The rest of the suggestions are in line with my current plans. BTW, it really appears to me that external moisture got into this area vs gear oil leaking out. I had checked my gear oil level and it was at the right level.
I really appreciate all the replies and advice.
 

pnora

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Apr 21, 2020
Messages
3,068
Reaction score
3,327
Location
Ishpeming, Mi.
Thanks to all the great replies. I don't have a press so am using a shop to do the upgrade on my Diff (resurrecting my original SureGrip as in replacement), I am having them do the complete rebuild on the Axels. Everything listed on "pnora's" response is what I am having them do.
On the axel housing itself, I already have new gaskets for Backing Plate to Housing (coated metal) and then from Axel plate to Backing plate (foam).
I will add the Two additions noted in your posts:
@pnora: step 1. Remove and Clean the Vent. I don't know what this is so could use some guidance.
@493 Mike: Add a bead of sealant on the passenger side due to the pitting. Perfect I will do this. I expect I should add a bead right up next to that second shoulder inside the housing so when I press in the seal it butts right up to it??? or press in the seal and then add to the face/housing joint on external side or just a thin layer on the housing surface where the seal will press in.
One extra question on the gasket between Backing plate and axel housing. There is a ring ridge on the gasket. Should it be facing in or out.

The rest of the suggestions are in line with my current plans. BTW, it really appears to me that external moisture got into this area vs gear oil leaking out. I had checked my gear oil level and it was at the right level.
I really appreciate all the replies and advice.

The vent can cause leaks if it is stuck or plugged up. Just un-screw it and wash it out good. Blow it out. The cap should become loose which is normal. As far as the other suggestions I believe he was referring to pits possibly causing seepage where the seal sits. If pitted just apply a light coat of RTV to the outside of the seal and drive it in. Looks like you have the rest on track.
 

dvw

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Feb 16, 2010
Messages
6,846
Reaction score
10,782
Location
waterford mi
I doubt if both bearings are noisy. Not impossible. In my years in this hobby, I've one factory axle bearing fail in an 8 3/4. Started messing with this stuff in 1974.
Doug
 

HS 69 Charger

Member
Local time
9:52 AM
Joined
Apr 5, 2022
Messages
19
Reaction score
6
Location
Overland Park, KS
Thanks @pnora
And @dvw, sorry if i am confusing everyone on the two separate issues (Diff and Axel). The Diff failure occurred in 1982. Yep that's a few years ago. Being in HighSchool and no money I simply swapped it with a standard Diff (741 case) from a local Salvage Yard. That worked fine for a long time but then the Axel started howling.
I just retired and decided that original SureGrip Diff (yes i kept it), needed to be rebuilt to put in place of the "very long term stand-in of the Salvage yard Standard Diff". Since I was going to have to pay a shop, I just decided now was the time for full restoration back to my factory specs (yep 40 years later). So i am getting the work all done at once.
Upon disassembly of the diff my shop guy could tell me the original SureGrip diff failure appeared to be in the Carrier bearings.
And you see from the picks above (which matches what both my shop guy and I saw on the axel bearing) that on the passenger side it had contamination and was the failure point. So this appears to be the "current' howl/growl.
So I am close to fixing the current Axel problem and restoring my original Suregrip Diff (all new parts back in original 489 Case.
And I can't wait to get back on the road. Its been a long time coming for the SureGrip Diff.
thanks again for all the advice as it really helps close the loop.
And thank DVW for caring that I am not "over" fixing or getting taken on what needs to be replaced. Very nice.
Martin
 

HS 69 Charger

Member
Local time
9:52 AM
Joined
Apr 5, 2022
Messages
19
Reaction score
6
Location
Overland Park, KS
Follow up on my Axel and Diff upgrade. All are back from the shop and I have started the reinstall. Axel end play adjustment went great (after the shop corrected the reversed adjustment plate-which seriously erodes my confidence). At least after the correction it all went together smoothly. I am still working on Brake items (wheels done but also swapping Master Cylinder). While I work on that I have a couple questions on the SureGrip.
  • Its been 40plus years since i had the SureGrip on this car so I don't remember what normal is. But now that the SureGrip is in, hand turning the wheels is quite a chore. You can hand turn the drive shaft with muscle. I can only turn the Wheel Hub using a 1ft 2x2 across the studs to get leverage. Turning forward (wheel rotation) is tough and turning backward is very tough but doable. Is this simply the action of the SureGrip? I expect it must have friction to get both wheels locked up for no single wheel spinning so it does make sense. I'm just cautious and want confirmation from someone with experience. I should say since I was just assembling and adjusting the Axel End Play, I did not have the Diff Fluid in yet. Will be adding that tomorrow and letting it sit overnight with a few manual turns.
  • If the SureGrip is normal, then any advice on adjusting the brake shoes given its already hard to turn. Will be a bit easier with Wheel on for leverage but I assume it will still be fairly high friction.
Thanks for any feedback. I am hoping this week the wheels land on the street for a test drive. I do plan to do the Jack Stand breakin as suggested on other posts and with the manuals on the YUKON gears and AUBURN Diff.
 

HS 69 Charger

Member
Local time
9:52 AM
Joined
Apr 5, 2022
Messages
19
Reaction score
6
Location
Overland Park, KS
Still hoping for some feedback on this question: (see full post above).
After changing from a standard Differential to a SureGrip, I noticed Hand turning the wheel is much more difficult. Is this normal and simply by design of the SureGrip. Makes sense but wanted to confirm.
Forward (wheel rotation) is tough and turning backward is very tough but doable.
 

pnora

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Apr 21, 2020
Messages
3,068
Reaction score
3,327
Location
Ishpeming, Mi.
Still hoping for some feedback on this question: (see full post above).
After changing from a standard Differential to a SureGrip, I noticed Hand turning the wheel is much more difficult. Is this normal and simply by design of the SureGrip. Makes sense but wanted to confirm.
Forward (wheel rotation) is tough and turning backward is very tough but doable.
It will take more force to rotate the wheel. I assume drums or rotors are off when you are doing this?
 

HS 69 Charger

Member
Local time
9:52 AM
Joined
Apr 5, 2022
Messages
19
Reaction score
6
Location
Overland Park, KS
Thanks. Yes the Drums and Wheels were off so I was turning at the hub. which is why I was using the leverage of the 2x2.
I have added the drums and wheels and have the rear brakes backed off to minimum. I can hand turn the wheel but definitely takes force. Much more in reverse rotation. Both wheels turn correctly forward when turning one in forward. Had filled gear oil yesterday so everything has been soaking in gear oil overnight. No leaks but no operational heat yet either.
I plan to run on Jack Stands to at least warm it up and make sure forward and reverse work (without strange noises) before hitting the pavement. will watch temp with IR gun at center and hub areas.
I am waiting on a master cylinder and then brake bleed before I can hit the streets but at least I can test on Jack stands. I am actually up on a Quick Jack car lift now but plan to lower to axel on jack stands to get the drive shaft alignment more normal.
Any other suggestions let me know. Getting close to moment of truth.
Thanks,
Martin
 

pnora

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Apr 21, 2020
Messages
3,068
Reaction score
3,327
Location
Ishpeming, Mi.
The one thing to consider is the increased force is also increased when the driveshaft is installed. You are now turning the transmission. Most likely with the driveshaft off it would turn equal both ways.
 

HS 69 Charger

Member
Local time
9:52 AM
Joined
Apr 5, 2022
Messages
19
Reaction score
6
Location
Overland Park, KS
That makes sense on the reverse involved with the transmission gearing.
So I went for it and did the jack stand bench test. NO NOISES!!! Was very happy with that.
Both forward and Reverse worked fine and I monitored the temp and it seemed to be a reasonable climb over the full 30 min.
Engine was running about 1000RPM as I did not kick down to idle after warm up.
With everything warm it was "easier" to turn in both directions. Not easy but easier.

Here are the temp readings. I'm not really sure what temp and the Diff area would constitute a problem but would like advice on what to watch for as a limit.

Driver Passenger
Time Mileage Drum Hub Diff Hub Drum
0 75 75 75 75 75
5min 51 80 80 90 80 93
10min 54.5 86 85 106 87 105
15min 57 87 86 120 93 110
20min 60.5 90 90 125 98 113
25min 64 94 93 133 99 110
Stopped and then put in reverse
5min 94 95 134 105 120

The screenshot is easier to read
Differential Jack Stand Bench Test Temps.jpg
 

pnora

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Apr 21, 2020
Messages
3,068
Reaction score
3,327
Location
Ishpeming, Mi.
To be honest you are way over thinking this. I never paid any attention to heat unless I suspected a problem.
 

493 Mike

FBBO Gold Member
FBBO Gold Member
Local time
10:52 AM
Joined
Dec 25, 2011
Messages
4,458
Reaction score
4,981
Location
White Cloud, MI
I have been reading this entire thread as it unfolds and, not to nit-pick but, axle is not spelled axel. FYI.
Mike
 

HS 69 Charger

Member
Local time
9:52 AM
Joined
Apr 5, 2022
Messages
19
Reaction score
6
Location
Overland Park, KS
@pnora I'm sure your right. When its the first attempt at this project I am a bit cautious. Plus the YUKON pamphlet with the Ring/Pinon had big bold all caps double sized type "DO NOT OVERHEAT THE OIL" That had my attention...smile.
Thanks for your help and keeping me grounded.
Martin
 
Top