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  • Dip stick Superior gear box

    Posted by Art on June 15, 2021 at 7:56 pm

    I have a vent in top of my superior gear box but my friend has a dip stick in his, Can I add that?? Top pic is mine, bottom is a friend, I don’t think I have that hole his dipstick is in>

    Glenn replied 5 years, 2 months ago 7 Members · 9 Replies
  • 9 Replies
  • Bernard

    Member
    June 16, 2021 at 10:17 am

    Art I’m wondering same thing.

  • Dick

    Member
    June 16, 2021 at 4:54 pm

    I’m pretty sure that mine has 1/4″ DOT brake line coming out of it that vents up near the ceiling of the engine bay. FYI, don’t know if my gear box is Superior… just reacting to vent hole reference.

  • Art

    Member
    June 17, 2021 at 4:04 am

    Vent is needed for the gear box and early ones were vented directly on top of gear box, later the line was added to extend vent preventing it from venting on top of unit.

  • Jon

    Member
    June 17, 2021 at 9:20 am

    Top pic on mine it has a pop-it valve on top for vent, with out a dip stick to check oil I need to remove plug on side and see if oil comes out, when I changed oil in it I filled oil till it came out of side hole. Jeff you say newer boxes have a long tube and a filter for vent??

  • Glenn

    Member
    June 17, 2021 at 11:54 am

    Art, here is a picture of my old box before Jeff replaced it due to a blown seal. The new one has the same vent line with no filter on it…just open at the top if that’s what you’re asking.

  • Jon

    Member
    June 20, 2021 at 10:53 pm

    On a related note, I was doing a little digging as to the recommended change interval for the gearbox oil. On the Superior website, they recommend between 250 and 1000 hours of use depending on the “severity of the environment.” On a Prevost service posting I saw somewhere, it said 50K miles. Given those parameters, is changing it every 12 or 18 months a reasonable approach for someone who might max out at 10-15K miles, per year?

    Per the printing on my (new) gearbox, Mobile Synthetic SHC 630, or equivalent, is the preferred lubricant. The same Prevost posting showed 75w90 synthetic…didn’t think that was quite the same thing as shc 630…

    The fire hose continues to point at my mouth…

  • Jon

    Member
    June 21, 2021 at 8:00 am

    I have heard of gear box replacements, usually due to leaking seals so my guess is they are robust. If Prevost suggests 50,000 miles, they likely are basing that on millions of miles of real world usage so I would say that is reasonable.

    Keep in mind that if we watch the temp gauge on the coach as it cycles we would see that unless a coach had only driver air in use most of the time the fan clutch is disengaged a lot of the time so the gear box is not under load all 50,000 miles.

    I buy the recommended oil on line.

  • John & Billie Jo

    Member
    June 21, 2021 at 9:38 am

    Hey Robert on that 1/4 line what is on top of that? And how is the new one vented? Can you post a pic of the new one? Thanks’

  • Greg

    Member
    June 21, 2021 at 8:02 pm

    Hi, Art…here are two pics. You’ll see the vent line going up in the first pic and the open end at the ceiling in the second. There is nothing inline with the vent hose….just straight 1/4″ DOT line.

    Hope this gives you the info you want…

    p.s. I had a chat with a seated coach operator, today, and they change their gear oil at 50K miles per the Prevost recs.

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