Friday, March 24, 2023

The ONLY WAY to fix a leaking 12-bolt GM rear diff pinion seal | Hagerty DIY

Main The ONLY WAY to fix a leaking 12-bolt GM rear diff pinion seal | Hagerty DIY

Viewing 36 posts - 1 through 36 (of 36 total)
  • Author
  • #39762

    Does your rear diff leak gear oil everywhere? Do you keep installing a new pinion seal and having the same problem? Everyone has or will have this problem …

    Bek Erkebaev

    Please show Subaru motor fixing

    ja smith

    Remove rubber part from old seal. Remove rubber part from new seal. You see where I going?


    Should make those spacers and sell em.

    Racer 67

    I see exactly whats goin on! Thank u very much for this info i needed to know this i have a 69 c-10 and a 67 impala!


    I love Hagerty's videos so much I think I need to buy a classic car just so I can get their insurance

    Jonathan Perley

    I'm confused if the yoke is bottomed out in the seal how is a shim going to help when the sealing surface is not touching the end of the yoke it seems that the sealing surface is too short!


    Good find! Looks like you could turn the flange off of the seal so the outer edge is at the same height as the lip on the dust side. Effectively narrowing the seal the distance needed to get the inner lip on the yoke journal. Then install the seal until it's flush with the housing. The flush outer edge will insure the seal lips are perpendicular to the yoke. No extra metal or fabrication needed.


    What heck man? I find it hard to believe that no one is making car 12 bolt seals considering how popular the axle is within the muscle car community. I have yet to find someone who was enthused about building a truck 12 bolt….

    Izaac Banks

    Sound like deboss garage today

    Abunai One

    I recently had a shop install a Posi unit in my 10 bolt rear end and the shop called me to tell me they weren't happy in the way it was sealing so hopefully they watched your video in case a 10 bolt rear end has the same issue. It hasn't leaked any yet.


    Well that explains everything! I was wondering why the new seal didn’t fit like the original when i rebuilt my 12 bolt last year.. great… now i need to be on the lookout for leaks… thanks for the tip!!!!

    Joe Nelson

    Thank you that explains why no matter what manufacturer seal I use it still leaks I learned something tonight


    Doesn't that push the seal into the pinion yoke and cause the cap on the yoke to ride on the seal seat ring?


    Get a Ford 9 inch.

    Victor Bitter

    I wonder if a Salsbury 10 bolt diff seal would work?

    EA. jam


    EA. jam

    Most will just drive it with a small leaking

    Stephen Bellamy

    Is that a frog eye sprite bonnet in the back ground


    But if the yoke is bottomed out in the seal spacing it from the diff housing wont make a difference no?


    The seal on my 9 inch needs replaced.

    Charlie B

    That’s a great tip

    Brian Grahn

    Correct me if I'm wrong, but the yoke still on goes in so far, on the seal, because of the construction of the of the seal. You will have the correct spacing to the bearing however.

    Martin Morales

    Pongan subtítulos en español a sus vídeos!

    สุทัศน์ พึ่งวิทย์


    John Doe

    The pinion bearing is supposed to move 1/8-1/4 inch?

    Hal 1000

    Na. Too much work. The easiest way it to through that pos in the recycling bin and use a real diff

    Randy Schartiger

    great info thank you for sharing!

    Cat’s Garage

    what exactly did you use for the ring?..was that custom made?

    Danny Wilsher

    I'm very curious…. I watched your last video when you did this modification. What I am wondering is if you push the seal as far as it will go up on the yoke (bottoming it out against the yoke) and it is not going far enough to seal on the sealing surface of the yoke, how is the spacer ring making the seal go past where it bottomed out on the surface of the yoke when it wouldn't go past the bottoming out without the spacer. Looks to me like you are not gaining anything with the spacer. When you tighten the nut on the yoke, it is going to crush the seal and ruin all chances of any kind of sealing. Also the yoke will be rubbing on the seal and cause almost instant failure. Only way this ring spacer will do any good is if when you demonstrated the oil sealing part of the seal not going far enough on the sealing surface of the yoke, there was still some space between the front of the seal and the back of the yoke. The way it appears in the video is you bottomed the front of the seal out against the back of the yoke. If this is the case, then the spacer ring will make more problems than it will fix.

    But all this analyzing I'm doing may be all wrong if there is plenty of room for the seal to go 1/8 inch closer to the back of the yoke without hitting. If that is the case, then I just wasted 10 minutes of time….. But in my defense….. it didn't appear that way.


    I dunno, man. Looks good to me, but I just got told off when I dared ask about if it were possible/a big deal to reduce some costs by doing some of the work myself (simple body work to replace a damaged door and repaint) and bring things in when my car was at the point of needing a professional shop. Evidently, everyone's a "youtube mechanic" these days and his 40 years to my 20 years working on cars meant he was right to get pissy at having to do less work and still get paid for his time, and it'd be like "bringing your own floss to a dentist appointment." Never heard someone talk themselves out of a $1000+ (quoted) job so quick.

    Hakim Idris



    No more barn finds? SAD. I turned my notification button Off.

    yep me

    Great job, on the info


    Any way to cross reference another manufacturer’s part. Ford 9” possibly?


    Good tip

Viewing 36 posts - 1 through 36 (of 36 total)
  • You must be logged in to reply to this topic.