Bop 8.2 axle repair question

Discussion in 'Got gears?' started by srobinr, May 28, 2022.

  1. srobinr

    srobinr Well-Known Member

    Good day v8buick, I finally got some time to work on an issue I have put off since I got the car. I noticed gear oil leaking out my driver side axle so I figured its the axle shaft oil seal, so I took the drum off went to inspect and noticed that there is some type of dried blue stuff around and inside the back plate flange plate. The other side of the car doesn’t have that blue stuff. Does anyone know what that stuff is?

    (10bolt 8.2 bop 68) It’s a 1382700 2-N axle, so it goes wheel, backing plate flange, bearing, bearing retainer all on the axle then lastly the oil seal inside the actual axle housing. I have it all out and about to put in my new seal but the chassis manual states to “apply sealer to O.D. Of new seal”, what is this sealer they are talking about?
    The next instructions in the book says top then pack the cavity with wheel bearing grease, so is that the same substance as a “sealer”?

    Ok thanks and I hope everyone has a good Memorial Day Weekend, God bless
     
  2. srobinr

    srobinr Well-Known Member

    here’s a couple pics one is looking from the front and the other pic is looking from the black side
     

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  3. TrunkMonkey

    TrunkMonkey Well-Known Member

    That looks like someone went batshit crazy with blue RTV trying to stop a leaking seal.

    I have not done work on an 8.2 BOP since the 70s, so I'll defer to others.

    (What parts are available or not)
     
  4. pbr400

    pbr400 68GS400

    There is a paper gasket that goes between that flat, four hole plate (flange) and the housing. It does look like someone replaced that gasket (and gooped it all around, as stated above) with blue sealer, but wheel bearing grease shouldn’t make it that far.
    The seal should be a regular parts store item unless it’s a ‘68 GS or Sportwagon. (Be careful-a lot of catalogs and parts stores list more than one rear end).
    Patrick
     
    Last edited: May 29, 2022
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

  6. srobinr

    srobinr Well-Known Member

    Thanks for the help and quick reply’s. I got all the correct parts now I’m kinda just wondering if by “sealer” they mean a wheel bearing grease or something else (like blue rtv silicone). Thanks again big time
     

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  7. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I would use something like this,

    https://www.permatex.com/products/g...nts/permatex-form-a-gasket-no-2-sealant-3-oz/

    That's what I used on the outside of the front crank neoprene seal in the timing cover.
     
  8. pbr400

    pbr400 68GS400

    Sealant isn’t grease. Check the factory service manual for GM specs,but it’s probably ‘Room Temperature Vulcanizing (RTV) number xxxxxxx.’
    Patrick
     
    Last edited: May 29, 2022
  9. BrianTrick

    BrianTrick Brian Trick

    Someone gooped that rtv in there for a reason. There must have been a previous leak and they tried to fix it,but that will not work. The proper gasket will do nothing to stop the leak. I would inspect the bearing and shaft for any signs of abnormal wear. Is the inner diameter race of the bearing turning on the shaft? I would also look at the bore at the end of the axle tube,where the bearing sits into. Look along the topside for any damage or signs of bad wear. If the bearing ever failed,it could have possibly chewed up the inside of the axle tube.
    Post more pictures and keep us updated.
     
    TrunkMonkey and Max Damage like this.
  10. srobinr

    srobinr Well-Known Member

    The actual axle and old bearings look fine. The bore/housing does have some nicks and scratches that potentially could be the issue. I will recheck the diameter race again when I tear down. Searched the manual and no luck on identification of sealant, but the permatex formagasket works well(i think). I do think the old blue rtv is from someone trying to repair the scruffed up housing/bore. Is it possible to replace Just the rear a diff axle housing tubes? Or does that warrant a whole new rear diff.

    I Did 2 test drives, after the first (30 mins) I came back and saw ever so slightly saw some of the permatext sealant around and outside the bore where I installed it, but its not a lot, but still doesn’t seem right- so I tore it down and inspected and it “looks fine”. But im still not sure if the residual fluid kinda coming out is from me installing it/the extra being pressed out. Going to test drive it again tonight and keep inspecting.

    Here’s a couple pics you can see a the condition of the housing and also the fluid (permatex and hopefully not gear oil)
     

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  11. monzaz

    monzaz Jim

    Ready... here we go.
    The red color stuff in these newest pics is GREASE...wheel bearing grease. The bearing is a SEALED bearing ....meaning it is packed with wheel bearing grease and sealed. IT never gets any more grease that it has sealed inside the bearing. Period.
    Now, To GM instructions - I get the sealant (RTV) on the OD of the seal before it is installed into the housing tube end... Good stuff there. Sealant takes up the imperfections in the housing if someone used a screw driver or other pry instrument to remove the doughnut type axle seal and scared the inner tube sealing area. (I DO THIS WITH ALL SEALS OD FOR INSTALL, PINION, AXLE, ETC WITH A METAL TO METAL CONTACT SEAL AREA.)
    now ON TO THE WEIRD PART OF THE gm INSTRUCTIONS. Filling housing tube end cavity with front wheel bearing grease ... I can ONLY think this acts as some kind of cooling effect against the sealed bearing or maybe even the seal for lubrication? I put grease or oil on the axle shaft ID of seal to insure it has enough lube on the first few runs. Then the inner oil slosh should cover the rest of the time when you turn corners.
    I have never filled the cavity from the seal to the outside of the tube end with grease?? It would also create a pretty good hydro-lock when trying to slide the axle shaft in the housing tube end too. blowing the seal lip to let air escape.
    Now for the gasket on the housing tube flange end and retaining plate....Another weird area with may questions.
    That gasket is not for sealing the tube ...it really should not be leaking anything from the seal outward if install went correct and housing seal surface is not damaged.
    Pontiac never even used seals (paper material) they used a Stainless / tin type metal shim...
    So as far as the paper gasket my best idea is that GM used it to keep parts from RUSTING together making parts release cleanly from each other for maintenance.
    Also look at your retaining plate on most there is a raised area under the axle shaft stamped into the plate design that does not even touch the gasket and this would let fluid pass right out of the tube into the drum. sooo WHY? I do know.... on the 55-64 Chevy they had a weep hole system that let oil / grease come out of the back side of the drum backing plate just below the axle tube it was to divert the oil from the cupped retaining plate that sealed the bearing to the tube end plate area out the back side of the drum baking plate and out under the car on the back side of the wheel drum area. That was sealed in by the retaining plate to let a customer know the axle bearing and or seal was starting to let go and this would prevent the brake parts from getting loaded with oil so you would not have brake stopping compromised.
    BUT on A body cars of the 64-72 era...THIS is NOT SO... WHY would GM build that so it drips right onto the inner drum stopping machined surface????
    Some one GOOF? Did they design the plate first them find a sealed bearing or change bearing design??? Or what?
    I do rear differentials, BUT logically have not found a reason for this stuff yet.
    retaining plate design and gaskets for the tube end and retaining plate.

    Dig around see what info from GM you can find.

    So in all - you should change your inner tube axle seal and you should RTV / Seal the OD surface of the seal and or ID of the tube where the seal seats. You should at very least grease the axle seal lip (oil it) and finally clean the housing tube surface area where your bearing will slide into the housing tube end and seat...light bit of oil on your finger and apply it to that cleaned surface area so the axle bearing OD will not stick the next time you want to remove it for maintenance. You can use the retaining plate gaskets if you feel it necessary and even one behind the backing plate to the housing tube end. It will not even hurt to use RTV between the flat mounting surfaces.... BUT IS IT NECESSARY to prevent leaks??? NO. It just should not be leaking past the inner axle seal ( thought.... unless you pack the cavity full of grease like gm says) REMEMBER to what I said about the gasket under the retaining plate and how it will not seal under the axle as there is a raised area on the plate... wink wink.) I have not used them for years on rebuilds and have not had any issues.
    We do not build 100 point show car rears here either ...the ones we did do for show customers provided all the crazy parts they wanted installed to do so and we did. :)

    Hope some of this helps.
    Jim
    JD Race
     
  12. srobinr

    srobinr Well-Known Member

    Update: Still leaking axle oil, now I know why there was blue rtv all in there. Keep it from leaking. It’s the damaged axle housing. Going to tear down and apply blue rtv along with a new oil seal again. Have new 18” wheels waiting to install but not going to until i fix the leak since it will continue to stain my old tire/rims. In the meantime does anyone have a new rear end for sale that will pair well with my 455?” Thanks again for all the reply’s has helped tremendously.
     

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  13. monzaz

    monzaz Jim

    tHAT IS JUST AN EASY FIX. i DO NOT SEE HOW IT KEEPS LEAKING. sEALED BEARING AXLE SYSTEMS ARE NICE AS THE DOUGH NUT SEAL TAKES CARE OF THE LEAKING AND IF YOU HAVE TO YOU CAn RTV around the OD of the sealed bearing to make certain it does not leak.
    I really have to believe something is being missed here. ???

    IF it was the Oiled bearing bolt in axles you would likely need to resort to a NEW rear end... BUT this really should be fixable. ??

    When you put the seal on the axle shaft does it slide on kind of tight in front of the bearing? IS there a groove in the axleshaft where the bearing rides.
    DO NOT PUT grease in the tube end between the bearing and the seal. !!!
    Call me if you want.

    Sorry for the caps not yelling in the first paragraph area.
    Jim
    JD
     
  14. monzaz

    monzaz Jim

    I will repeat....DO NOT DO STEP 4.
     
  15. TrunkMonkey

    TrunkMonkey Well-Known Member

    Jim.

    You have seen a crapton more of these than I have, but I am thinking this spun and has created a clearance (and sealing) issue. RTV *should* stop a hemorrhage, but only if it is applied here, and not at the flange (where it is "too late").

    But I am only hazarding a guess.

    upload_2022-6-5_22-22-40.png
     
  16. srobinr

    srobinr Well-Known Member

    Ok I think I understand, this next seal im installing im not going to add any red grease and will use rtv instead, where the bearing sits (red arrow).

    “When you put the seal on the axle shaft does it slide on kind of tight in front of the bearing? IS there a groove in the axleshaft where the bearing rides.” - Yes the red arrow is where the bearing sits and it is scuffed up pretty bad. In addition the seal is installed first into the axle housing, I use a slide hammer to install it, then the axle shaft with bearing and bearing retainer is installed and slides right in. The seal doesnt install on the axle before installing in the housing, unless you mean just dry mocking it up I will have to check.

    Ill give a call, thanks
     
  17. BrianTrick

    BrianTrick Brian Trick

    Can we see a further-away shot of that axle shaft? I would like to see the area in front and behind the bearing. I am curious to see if that axle was replaced with a later shaft that originally had a roller bearing on it. I disassembled a rearend like that a few weeks ago. The whole inside of the drum and brakes were coated with sludge and oil,and you could see where something was trying to stop the same problem,but the shaft was wrong. Just a thought.
     
  18. monzaz

    monzaz Jim

    The bearing has NOTHING to do with sealing.
     
  19. monzaz

    monzaz Jim

    Bearing is a slip fit. The seal is in the tube the axle shaft slides through the seal hole. YOU DO NOT PUT GREASE IN BETWEEN THE BEARING and the seal. This is why you are leaking!
     
  20. monzaz

    monzaz Jim

    here is a picture I modified yours. green arrows are where the seal should be sealing.
     

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