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Ultrashift shifting problem?

Discussion in 'Truck Talk' started by jjoerger, May 29, 2011.

  1. jjoerger

    jjoerger Seasoned Expediter

    A few days ago our Ultrashift transmission started acting up. It would not go into gear at times either up shifting or down shifting. We had to pull over on the side of the road and shut our battery switch off for 2 minutes to get the transmission to reset. This went on several times for about 24 hours.
    A driver told us that most of the Ultrashift problems were electrical. He told me to spray WD 40 on the battery terminals. Since there was nothing to lose by trying this I did. And the transmission has been working fine since. 3 days and 1800 miles with lots of shifting in the northeast and the mountains between Connecticut and Florida. (Today I pulled the battery cables off and cleaned all the connections until they were nice and shiny.)
    I plan to take it to the shop Tuesday to have it checked out.
    Is there anything they can do if it is operating properly or am I just wasting my time and money?
  2. matlack

    matlack Rookie Expediter

    We had similar problems and it was corrosion inside the battery cut off switch housing.

    When I took it apart it looked like a molded box of baking soda fell out it.

    We replaced the cutoff switch.

    You can bypass the cut off switch to test and see if that is the problem.

    This also solved the fault code that was showing on the digital readout at engine startup.

    Also check the fuses, relays and circuit breakers; sometimes the can become loose.
  3. cheri1122

    cheri1122 Expert Expediter

    A tech told me the same thing: when the transmission goes into 'defense' mode, [refusing to shift], the problem is electrical. If the battery cables were the whole problem, it's solved. :)
  4. jjoerger

    jjoerger Seasoned Expediter

    I checked my codes and had 3 inactives.
    72-Failure to select a rail.
    73-Failure to engage a gear.
    91-Check of the wiring integrity.

    I am thinking that I will take it in to the shop and have the fluid changed and clutch adjusted and see if having the ECU reprogrammed would benefit me. Hopefully when it is hooked up to the computer they will be able to tell if there are any other problems.
  5. matlack

    matlack Rookie Expediter

    We had ours hooked up at the Freightliner Dealer and it showed like two pages of errors, most of the codes made no sense which lead the tech to suspect the Motherboard, but all was fine after by-passing the cutoff switch.

    The cutoff switch looked fine from the outside of it, but the inside must have sweated as the internal parts of it had badly corroded.
    I estimate over three tablespoons of corrosion fell out it once it was taken apart.

    This switch was mounted through the floor of the cab beside the driver's seat, with the lever part on the inside of the cab but the housing and it's battery cable connections underneath (outside of) the cab.

    Also after by-passing the Cutoff switch it was like having fresh batteries as the starter turned much faster.

    New cutoff switch cost varies around $40 and are available in different Parts Stores.


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