Welcome to the Hatteras Owners Forum & Gallery. Sign Up or Login

Enter partial or full part description to search the Hatteras/Cabo parts catalog (for example: breaker or gauge)
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 15
  1. #1

    Foam O. Trans dip stick

    Allison m20 behind 8v92ti. Stbd oil level low mark when cold. Oil honey color. Idled the engine 1/2 hour periodically running to 1000 rpm. Oil level rose to 1/2 between full and low but foamy oil dip stick. Added 1 qt 40w, oil level at full foamy.I have read that if overfilled will cause foaming, but under filled? Temps: at brass fitting to trans oil filter 125 by infrared. Lower er gauge - 137. Lower helm - 150

  2. #2

    Re: Foam O. Trans dip stick

    Quote Originally Posted by Chasemmc View Post
    Allison m20 behind 8v92ti. Stbd oil level low mark when cold. Oil honey color. Idled the engine 1/2 hour periodically running to 1000 rpm. Oil level rose to 1/2 between full and low but foamy oil dip stick. Added 1 qt 40w, oil level at full foamy.I have read that if overfilled will cause foaming, but under filled? Temps: at brass fitting to trans oil filter 125 by infrared. Lower er gauge - 137. Lower helm - 150
    Could be getting air through the suction side, over filled or the gear is whipping up the oil. There’s a guard above one of the gears in the trans. If that has shifted this will happen but it’s rarely the issue.
    Jack Sardina

  3. #3

    Re: Foam O. Trans dip stick

    Do u think operating the transmission will damage it?

  4. #4

    Re: Foam O. Trans dip stick

    Typically no but can’t say without knowing what’s really going on
    Jack Sardina

  5. #5

    Re: Foam O. Trans dip stick

    The operating temp at the sea trail was 153 degrees. I'll monitor while operating. It shifts fine. Wasn't there a good Allison shop in Alabama mentioned in the forum. Maybe I can call them, anyone remember the name?

  6. #6

    Thumbs up Re: Foam O. Trans dip stick

    Quote Originally Posted by Chasemmc View Post
    The operating temp at the sea trail was 153 degrees. I'll monitor while operating. It shifts fine. Wasn't there a good Allison shop in Alabama mentioned in the forum. Maybe I can call them, anyone remember the name?
    Acadian Marine Transmission ask for Brian. Broussard, Louisiana. His knowledge is amazing.

  7. #7

    Re: Foam O. Trans dip stick

    Thank you, I will give him a call

  8. #8

    Re: Foam O. Trans dip stick

    Brian was very helpful. I will repeat his knowledge for the benefit of the forum.Brian said that foam on the dipstick is due to an air leak on the suction side or low oil level. He said the reason the transmission first presents by not going into forward is that the oil has a more circuitous route than in reverse and pressure is bled off as it travels.He said temperature, while an indicator, is less important than pressure as low pressure allows the clutch plates to slip while underway. He said it should be between 135 - 150 psi. I think the temperature is monitored but not sure about the pressure. He said to add another qt. And see if that stops the foaming. The trans holds 5 qts plus whatever is in the lines and filter.

  9. #9

    Re: Foam O. Trans dip stick

    Has anyone put pressure gauges on their Allison MH-20's and if so where? Where would I find?
    mark

  10. #10

    Re: Foam O. Trans dip stick

    Quote Originally Posted by Chasemmc View Post
    Has anyone put pressure gauges on their Allison MH-20's and if so where? Where would I find?
    mark
    Don’t you have them already?
    Jack Sardina

Posting Permissions

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