Midwest Classic Insurance

Visit our community sponsor

Thanks Thanks:  0
Likes Likes:  2
Results 1 to 8 of 8

Thread: How do 818 axles break?

  1. #1
    Senior Member Dave 53's Avatar
    Join Date
    Jun 2020
    Location
    Danville CA
    Posts
    501
    Post Thanks / Like

    How do 818 axles break?

    I guess I know how they break - twisting them too hard. What I really mean is, what is the point of failure? What is the weak link?

    The outer CV shaft that goes into the hub sheared off in my case. Are there other points of failure experienced? Outer CV bearings? FFR provided axle shaft snapping? Inner CV joint failure? Something else?

    I will assume there is a range of parts quality from cheap ebay parts to some source unknown to me that makes super strong 1000hp high end professional race car parts. If you've had an axle failure, please share the perceived quality of your parts. If you have higher end / strengthened axles or CV joints, please share.

    Factory Five currently sells the FFR axle shaft for $95. And they sell a complete axle with both CV joints installed for $159. $64 for two CV joints installed - I'm gonna guess those CV joints are on the extreme low end of the spectrum. The build manual suggests parts from AutoZone.... I believe the original purchaser of my kit bought the complete FFR CV installed axles. $110 for the pair in 2017. I suspect the CV joints are of the lowest AutoZone quality. Is it enough to rebuild with Subaru OEM CV joints?

    I'm trying to figure out my strategy for fixing my broken axle. And give the same treatment to my unbroken axle. And have a spare. Hearing from others about what has failed and what has been working on a track car or maybe even more relevant, an autocross car would be most helpful in coming up with a plan.

    axle broken.jpg

  2. #2
    Senior Member EZ$'s Avatar
    Join Date
    Feb 2014
    Location
    San Ramon, CA
    Posts
    951
    Post Thanks / Like
    Damn Dave! You need to make a list of all the things that could fail and start checking them all out! I was going to see if you were heading over the C&C on Friday, but I think I know the answer. I think all of this falls into the "if it wasn't for bad luck..." category.
    Rick

    Mk4 with Mr. Bruce FIA body, 331 w/ Speedmaster Stack Injection, Full Width Roll Bar with high brake lights by i.e.427, IRS, ABS, PS, PB, FAST FI, First start 3/30/20, First go-kart 7/5/20, paint by Ken Pike

  3. #3
    Senior Member Dave 53's Avatar
    Join Date
    Jun 2020
    Location
    Danville CA
    Posts
    501
    Post Thanks / Like
    Quote Originally Posted by EZ$ View Post
    Damn Dave! You need to make a list of all the things that could fail and start checking them all out! I was going to see if you were heading over the C&C on Friday, but I think I know the answer. I think all of this falls into the "if it wasn't for bad luck..." category.
    I'm analyzing everything between the gear shift knob and the tires and between the gas pedal and the tires. I'm analyzing what parts are still left over from the previous owner that I don't know the history of. There may be others beating their 818 as hard as I do out on a track, but no one harder! Add to the list of what it takes to make an 818 into a proper track car - something better than AutoZone axles! Just trying to figure out what that "something" is.
    Last edited by Dave 53; 08-09-2023 at 06:12 PM.

  4. #4
    Senior Member Hobby Racer's Avatar
    Join Date
    Feb 2011
    Location
    Syracuse, NY
    Posts
    1,308
    Post Thanks / Like
    I've got hundreds if not thousands of track miles on my 818R using the FFR axles and Subaru OEM CV joints with no issues. Any shock loading like dumping the clutch or burnouts combined with sticky tires will put an extreme load on the axle shafts.

    They will brake at the narrowest point or where there is a sharp corner from machining/forming (stress riser).
    MK3.1 Roadster completed 2011
    818R built with EZ36R H6 completed 2018
    818R rebuild with a JDM Honda K24A

  5. Likes Sgt.Gator liked this post
  6. #5
    Senior Member Rob T's Avatar
    Join Date
    Feb 2016
    Location
    Woodruff, SC
    Posts
    519
    Post Thanks / Like
    Original axles on my car failed at the outer CV making crunching sounds. I did not wait for a total failure. I went with DSS axles. Since then I've had 85+ 15-20 minute track sessions. I probably drive at 7/10.

  7. #6
    Senior Member Dave 53's Avatar
    Join Date
    Jun 2020
    Location
    Danville CA
    Posts
    501
    Post Thanks / Like
    Quote Originally Posted by Rob T View Post
    Original axles on my car failed at the outer CV making crunching sounds. I did not wait for a total failure. I went with DSS axles. Since then I've had 85+ 15-20 minute track sessions. I probably drive at 7/10.
    Were your original axles the FFR built complete axle sets?

  8. #7
    Senior Member Rob T's Avatar
    Join Date
    Feb 2016
    Location
    Woodruff, SC
    Posts
    519
    Post Thanks / Like
    The original axles were NAPA rebuilt.

  9. #8
    Senior Member Dave 53's Avatar
    Join Date
    Jun 2020
    Location
    Danville CA
    Posts
    501
    Post Thanks / Like
    The DSS axles are $1,600 a pair. The FFR axles are $320 a pair. Any sayings come to mind?

    There are a couple of options in between, but for peace of mind, I'm getting the DSS axles.

  10. Likes J R Jones liked this post

Posting Permissions

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

Stewart Transport

Visit our community sponsor