Results 1 to 10 of 10

Thread: CV Meltdown

  1. #1
    Member
    Join Date
    Dec 2019
    Location
    Sisters Oregon
    Posts
    85

    CV Meltdown

    I had a unfortunate event two days ago.
    After a very spirited drive on central Oregon rural roads, after coming to a complete stop, I engaged First aggressively and my 72 T kinda blew up.
    It was the pass side half shaft. It left with a considerable amount of destruction. Brake caliber and brake caliber housing fitting (requiring a new trailing arm. It also punctured the WHEEL !
    thankful I was doing zero mph

  2. #2
    Senior Member
    Join Date
    Oct 2008
    Location
    Burford, ON, Canada
    Posts
    4,237
    Did the bolts back out or fail? I got a 914 from a fellow where his bolts came loose, and when he took off from a stoplight the CVJ took out the gearshift rod and did other damage.
    Porsche Historian, contact for Kardex & CoA-type Reports
    Addicted since 1975, ESR mbr# 2200 to 2024 03
    Researching Paint codes and Engine Build numbers

  3. #3
    Senior Member
    Join Date
    Oct 2010
    Location
    Southern Ca.
    Posts
    1,166
    I wouldn't call the bolts coming loose a CV meltdown , because that certainly seems what happened .

  4. #4
    Member
    Join Date
    Dec 2019
    Location
    Sisters Oregon
    Posts
    85
    they backed out. I went back to the scene of the crime and picked up all the pieces. One bolt was is sheared off, the remaining are all intact. I am surprised that I had no warning, no clunking no vibration, if it was loose I would have thought it would have given me some indication. In the process the half shaft ripped the caliper off breaking the caliper as well as the housing the caliper bolts to. I guess the question is should one use a thread sealant when installing these components?

  5. #5
    Senior Member bob joyce's Avatar
    Join Date
    Aug 2017
    Location
    el sobrante ca.
    Posts
    1,150
    new shore washers?

  6. #6
    Senior Member
    Join Date
    Oct 2008
    Location
    Burford, ON, Canada
    Posts
    4,237
    First, everything must be grease free. New Schnorr washers every time! You do have the hardened half moon plates for the Schnorr washers to seat on? A bit of Loctite blue 242 could be used. Torque them to spec in stages as you do wheel nuts. New bolts drilled for safety wire are a great option. After driving for a few hundred miles, check the torque again. Not a bad idea to do it again in a thousand miles. Really, the only reason they come loose is because they were not correctly installed.
    Porsche Historian, contact for Kardex & CoA-type Reports
    Addicted since 1975, ESR mbr# 2200 to 2024 03
    Researching Paint codes and Engine Build numbers

  7. #7
    Member
    Join Date
    Dec 2019
    Location
    Sisters Oregon
    Posts
    85
    Thanks to all who responded Got the car up in the air and checked the intact side(driver) all good and tight. I am ordering new washers, thanks for the advice.

  8. #8
    Senior Member 911quest's Avatar
    Join Date
    Mar 2006
    Location
    Louisville KY
    Posts
    1,530
    Double check the balls and inner cage. If they have wear they can cause binding which can lead to the axle bolts coming loose.
    Tony Proasi

    52 split window coupe

  9. #9
    Senior Member
    Join Date
    Oct 2008
    Location
    Burford, ON, Canada
    Posts
    4,237
    Thanks Tony, that is an interesting problem. I stand corrected then, it is not always incorrect assembly.
    Porsche Historian, contact for Kardex & CoA-type Reports
    Addicted since 1975, ESR mbr# 2200 to 2024 03
    Researching Paint codes and Engine Build numbers

  10. #10
    Senior Member kentf14's Avatar
    Join Date
    Feb 2010
    Location
    San Francisco, CA
    Posts
    1,914
    +100 to this advice.
    I had a local mobile mechanic torque my CV bolts w an impact wrench. Had the same failure as described above. Fortunately I was about a mile from home and the CV came loose off the output flange so it didn’t beat the underside of the car.
    Ever since this incident I compulsively check the bolts whenever I’m under the car, and keep a supply of fresh schnorr washers on hand. Oh, and I stopped using that mechanic
    Quote Originally Posted by davep View Post
    First, everything must be grease free. New Schnorr washers every time! You do have the hardened half moon plates for the Schnorr washers to seat on? A bit of Loctite blue 242 could be used. Torque them to spec in stages as you do wheel nuts. New bolts drilled for safety wire are a great option. After driving for a few hundred miles, check the torque again. Not a bad idea to do it again in a thousand miles. Really, the only reason they come loose is because they were not correctly installed.
    Last edited by kentf14; 02-01-2021 at 07:31 PM.
    E911SR & RGRUPPE
    '65 911 "The Ol' Gal" (long gone)
    '73 S Coupe #306

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Message Board Disclaimer and Terms of Use
This is a public forum. Messages posted here can be viewed by the public. The Early 911S Registry is not responsible for messages posted in its online forums, and any message will express the views of the author and not the Early 911S Registry. Use of online forums shall constitute the agreement of the user not to post anything of religious or political content, false and defamatory, inaccurate, abusive, vulgar, hateful, harassing, obscene, profane, sexually oriented, threatening, invasive of a person's privacy, or otherwise to violate the law and the further agreement of the user to be solely responsible for and hold the Early 911S Registry harmless in the event of any claim based on their message. Any viewer who finds a message objectionable should contact us immediately by email. The Early 911S Registry has the ability to remove objectionable messages and we will make every effort to do so, within a reasonable time frame, if we determine that removal is necessary.