355 - Gearbox leak | Page 2 | FerrariChat

355 Gearbox leak

Discussion in '348/355' started by MikeeB355, Jun 8, 2020.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. MikeeB355

    MikeeB355 Karting

    Dec 7, 2019
    82
    S Wales
    Full Name:
    Michel Bee
    Progress, I think...
    Ok I whipped the bumper, exhaust and pumpkin off this evening and think I've found the cause of the leak. It seems to me that the new Hill Engineering bearing assembly that I bought and fitted last week is letting some fluid seep out and it's being flung around the outer casing by centrifugal force,which would explain where the oil is gathering on the pumpkin casing.
    Looks like I'll be back on the phone to HE monday morning.
    I do feel a lot better now though, was really worried it was something more serious.
     
  2. Ferrarium

    Ferrarium F1 Veteran
    Rossa Subscribed

    Jul 28, 2018
    5,624
    Central NJ
    Full Name:
    Eric
    Wow that's interesting. Let us know what happens.
     
    MikeeB355 likes this.
  3. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    12,661
    San Carlos, CA
    Full Name:
    Mitchell Le
    While that is unusual, it is the second time in 6 months I have heard of that.
     
    MikeeB355 likes this.
  4. Ferrarium

    Ferrarium F1 Veteran
    Rossa Subscribed

    Jul 28, 2018
    5,624
    Central NJ
    Full Name:
    Eric
  5. MikeeB355

    MikeeB355 Karting

    Dec 7, 2019
    82
    S Wales
    Full Name:
    Michel Bee
    Ok this is starting to get on my nerves now.. Paul at Hill Engineering has been very helpful and feels the new bearing and seals are fine but suggested changing the O rings behind the flange so I did that last night but one short drive later and it was still leaking. It has to be the triple seals surely? I replaced them as per the YouTube video suggestion by warming them up then stretching them over a plastic sheath then crimping them with a jubilee clip. They have gone back to their original size now but they are still a bit loose and there is always oil at the bottom of the shaft on the spine side of the spindle. I'll try and upload a video to youtube as it's too big to post here..
     
  6. MikeeB355

    MikeeB355 Karting

    Dec 7, 2019
    82
    S Wales
    Full Name:
    Michel Bee
  7. MikeeB355

    MikeeB355 Karting

    Dec 7, 2019
    82
    S Wales
    Full Name:
    Michel Bee
  8. MikeeB355

    MikeeB355 Karting

    Dec 7, 2019
    82
    S Wales
    Full Name:
    Michel Bee
    Sorry for the overload today but this is I teresting and may prove it is actually brake fluid not transmission oil that's leaking?
    I had a small try catching the drips and when I picked it up just now it looked like the fluid had settled and separated when I moved it with clear fluidrunni g away, leaving all the dark crud on the base of the tray. Surely this must mean its clutch fluid leaking otherwise it would t separate in this manner?
    I'm guessing the crud is just clutch dust that was resident in the housing and gas been cleaned off by the fluid?
    Image Unavailable, Please Login
     
  9. Ferrarium

    Ferrarium F1 Veteran
    Rossa Subscribed

    Jul 28, 2018
    5,624
    Central NJ
    Full Name:
    Eric
    If its crude oil like engine or GB oil its not triple seals it. On the 348 the brake and clutch use the same fluid so if its hydraulic fluid then its triple seals. Check your reservoir level in the front bonnet there is an access panel for that right in front of the steering wheel in the front bonnet.

    Clean out the cover thoroughly with brake cleaner for next test btw. Oil and brake fluid have very different smells. If its very liquid, like water and near odorless its brake, if its thick its oil and it usually smells awful. If your sniffer is no good consistency is a good gauge..
     
  10. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    12,661
    San Carlos, CA
    Full Name:
    Mitchell Le
    Clutch fluid, hydraulic fluid, enters the gearbox by the clutch slave cylinder. You can put a dye in your gearbox to distinguish it from the clutch fluid. Or, you can use a gear oil of different color like Sweppco.

    If it is clutch fluid, the leak is your slave cylinder.
     
  11. MikeeB355

    MikeeB355 Karting

    Dec 7, 2019
    82
    S Wales
    Full Name:
    Michel Bee
    Well I've taken the decision to remove the bearing and send it back to Hill's for them to pressure check. I've replaced all the seals, again, despite them all looking like they were fitted in properly with no punches or leaks and it's still leaking. The drips I collected mixed easily with water thereby ruling out it could be gearbox oil.
    The bearing itself has got traces of fluid on the inside of the bearing and all the grease from I side has turned black and is leaking out, on a part that has done 20 to 25 miles, under light use whilst testing it out. If this comes back as fine then I dont think there is any other option than to trailer it to a garage and get them to look at it.
    And there I was thinking it would be straightforward lol
    Thanks again for all the help and advice throughout my trials, it is much appreciated.




     
  12. Ferrarium

    Ferrarium F1 Veteran
    Rossa Subscribed

    Jul 28, 2018
    5,624
    Central NJ
    Full Name:
    Eric
    Keep us posted, that bearing looked like it was slinging fluid alright.
     
    MikeeB355 likes this.
  13. emac

    emac Formula Junior
    Silver Subscribed

    Sep 14, 2014
    851
    upstate SC
    Full Name:
    ernest
    At 8 seconds in the first video it looks like one of the internal seals appears split. The next to farthest from the camera. Is that just the light or fluid?
     
  14. phrogs

    phrogs F1 Veteran
    Silver Subscribed

    Apr 13, 2004
    7,113
    Michigan
    They are split that's normal.
     
    MikeeB355 and emac like this.
  15. Ferrarium

    Ferrarium F1 Veteran
    Rossa Subscribed

    Jul 28, 2018
    5,624
    Central NJ
    Full Name:
    Eric
    btw a shop has no special diagnostic equipment for this. They will just buy new slave and bearings and seals and o-rings and reinstall everything.
     
  16. MikeeB355

    MikeeB355 Karting

    Dec 7, 2019
    82
    S Wales
    Full Name:
    Michel Bee
    Had the CRB back from Hill's yesterday, they were really helpful in checking it for me so it could be ruled out and was found to be working fine.
    Had some advice from a fellow Fchatter and after a bit of headscratching and double checking found the cause to be the large seal on the flange was to blame.
    Managed to fix it this evening and so far it seems to be fine, no leak.
    Pleased but I think I need to leave the spanner work to the professionals as this has been a real pain in the backside.
     
  17. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    12,661
    San Carlos, CA
    Full Name:
    Mitchell Le
    I thought you said you changed that seal at the beginning of all this.
     
  18. emac

    emac Formula Junior
    Silver Subscribed

    Sep 14, 2014
    851
    upstate SC
    Full Name:
    ernest
    Glad you found it and got it fixed. You learned a lot, that is worth something. Everyone on here has missed simple stuff. Dont let it discourage you from working on your car.
     
  19. USAF - 1

    USAF - 1 Rookie
    Silver Subscribed

    Mar 27, 2021
    24
    San Jose CA
    Full Name:
    Todd
    Sorry to resurrect an old thread, but I'm having the same issue here. When you refer to the "large seal" that ultimately solved the issue, which part number are you referring to? Thank you.
     

Share This Page