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Front Wheel Bearings

Discussion in '365 GT4 2+2/400/412' started by SouthJersey400i, Mar 22, 2019.

  1. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,202
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    I am in the process of changing my RF wheel bearing. The rear grease seal had leaked but otherwise bearings seemed okay once removed. After thorough cleaning I reinstalled new bearings, new rear seal, new dust cover and grease (see below). I have two issues:

    1. The dust cover is not real snug on the hub. When mounted the dust cover remains stationary while the hub is being turned by hand. This means there is metal to metal slippage between the hub and the outer ring of the dust cover and the rubber "dust" seal is stationary against the upright. I tried a little light lubricant between the rubber part and the upright but the cover slips so easily on hub it still slips.
    a. Should the dust cover be stationary or rotate with the hub? If dust cover rotates there will be a lot of friction with the upright.
    b. If it should rotate, has anyone this issue?
    c. Solutions? All I can think is to use some red Loctite between hub and cover.

    2. I followed manual to install hub. First torque to 25 Nm to set bearings. Then loosen and retorque to 15 Nm and back off 10 to 30 degrees and measure end float of hub, spec is 0.06 mm or 0.002". I get NO end float unless nut is actually loose and not touching washer. I can get hub to rotate (not spin) with 10 to 30 deg backed off but no end float. Should I leave it like that? I will need to use a shim washer to get cotter lined up in that position but that is acceptable practice. Note: I am using a Moly based "Disc Brake Bearing Grease", manual was not specific. It is quite thick and seems to be restricting hub rotation and end float when newly installed. I think it will loosen up once car is driven. What grease have you used?

    I am hoping to hear some comments in next couple days to finish this job up and move on to some suspension work. Thanks all.
    Ken
     
  2. Part Time

    Part Time Formula Junior
    Silver Subscribed

    Dec 16, 2013
    472
    Port St. Lucie, Fl
    Full Name:
    Gary Shore
    Ken...
    First make sure your inner grease seal is pressed into the hub "flush" with the hub surface, a light wipe of your finger with a touch of grease onto the inside lip will make it easy to slide over the machined surface of the hub.
    Also check the hub "step" for any rust, use fine - very fine emery cloth to polish it away.
    Old school method for installing hubs is assemble, snug castle nut, spin the hub, then back off one hole and insert cotter pin, a little play is OK because the hub and bearings will warm up and get snug.
    You do have the flat washer with a tooth inside it on the spindle under the castle nut, correct ?
    Depending on the thickness of your grease, the assembly should turn by hand and with a good spin should coast a bit, and you should feel "some" vertical-horizontal play.
    As far as the dust cap staying still while the hub spins, make sure the ends of the cotter pin are not so long as to be contacting the cap itself, and, it would be OK to take pliers and "twist" the sharp edge of the cap in a couple of spots to increase the friction between the inside of the hub and the edge of the cap.

    Gary
     
  3. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,202
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Gary
    Thanks for input. Bearings and seal "full home in hub. I was pretty good about cleaning and using Scotch-guard for any dings. Yes, I have the flat washer in place. I think I will have a good compromise setting the castle nut with just a small amount of play. Yeah, I went to that old school too.

    It is the dust seal outboard of the rear bearing and seal that I am struggling with, not the dust cap on top of the castle nut. It is a new piece but is not snug onto the hub. The "back" of the hub has a small step down for this dust seal. Any thoughts on that?
    Ken
     
  4. Part Time

    Part Time Formula Junior
    Silver Subscribed

    Dec 16, 2013
    472
    Port St. Lucie, Fl
    Full Name:
    Gary Shore
    Ken.....oh, ok.....from a good photo on ebay, it appears the secondary seal should force fit over a larger step cut onto the shank of the spindle. The rubber seal would stick out towards the inside of the hub, likely a bit larger than the actual grease seal mounted in the hub itself. OR....does it drive onto the back of the hub and then seal against the spindle, much as the grease seal does ? The shop manual drawing shows everything assembled, I can't see exactly how it installs.

    I will be at a local car show at a museum tomorrow, or else I could pull a wheel off and look at mine.

    I have worked on 100's of cars from recent to the 50's, they have all been just one grease seal in the hub....unless, of course you plan on entering a mud-bog race.
    Gary

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  5. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,202
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Gary
    Picture is the dust cover I am discussing. The lips on the seal actually extend outward away from the inner bearing. The intent is to seal on the large step up on the spindle shaft. The lips extend out a good 1/8" or more. The metal cap bottoms out against the hub which has a small step down in diameter, but it is NOT a snug fit onto the spindle. As it stands at the moment the firction of the lips on the spindle is much more than the friction to rotate the cap on the hub.

    Got cold again today in garage. Tomorrow I plan to pull the assembly off. I'll check the dust cap alone against the spindle to see if I can get it to rotate on its own. If i rotates okay on the spindle, I will find a way to tap down the edge of the dust cap to fix it to the hub, maybe some red Loctite.

    Hope you enjoyed show and museum. If you get a chance have a look at your set up, not sure you will see much without pulling caliper, disc and dust shield which I have off.

    As for why a dust seal? If you leave it off here will be a nice gap of about 1/4" between the greases seal and the spindle which will collect normal road dirt without going to the bog. (It is still an option to not use it??)
    Ken
     
  6. Ak Jim

    Ak Jim F1 Rookie
    Rossa Subscribed Owner

    Dec 23, 2007
    4,738
    North Pole AK
    Good info, thx for posting. This is on my todo list. Been working on garage for almost 3 years. It's about time to start working on the things in the garage!
     
  7. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,202
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    SUCCESS!
    I pulled hub off. Dust cap came right off of hub, hardly held on at all. I test fit dust cap on spindle by itself; inner lips run on spindle and outer lips run on a finished vertical surface on upright. It is pretty tight fit as is. I added a bit of grease to both surfaces and dust cover turns reasonably well but still drags. The old dust cover on the other hand spins easily on shaft (outer lips worn in places) and it is a real snug fit onto the hub. CONCLUSION: dust cover must spin with the hub; I knew it all along but it was not doing it. New dust cover not made to same tolerances as the old one; I will contact my supplier. I pinched in the sides of the dust cover in about 10 places and it required a few light taps to fit onto hub. Upon reassembly all is good.

    As for the adjustment of bearing: I re-torqued per manual and had to back off about 50 deg (vs. 10-30 in manual) to get any play and to line up cotter pin hole. It 'feels good', old school term. I plan to recheck bearing after putting first 500 miles on it in April.

    Through all of this post I have struggled to refrain from any metaphors about the dust seal!
    Ken
     
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