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chuckbear's avatar
chuckbear
Explorer
Jun 02, 2017

Unusual Occurrence

While driving on some local back roads we had a strange thing happen. We had been driving for a few hours that day and are into about a month of our current U.S. tour. Only doing 35 to 40 MPH and on hilly roads we suddenly lost the speedometer. Shortly thereafter while going up a small hill the transmission acted like it shifted itself into neutral. Shifting into drive 2 did nothing but downshifting into low gear, drive 1, downshifted the transmission and it shifted OK in drive for a while. Then suddenly it happened again. I have an SCT device connected to the OBD and the transmission was not showing above average temps and no error codes came up. We found a spot to pull over and check things. Fluid levels were right on and nothing appeared to be loose or disconnected. Just for grins, I reinstalled the 5 Star Tune and the speedometer came back and for the last few days, the transmission has behaved itself. But in the back of my mind every day, I worry about another episode. Has anyone else had something like this happen? 1999 F53 Bounder, V10. Chuck
Class A

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  • Dennis12's avatar
    Dennis12
    Explorer
    Jun 02, 2017
    Take it to a transmission man that you trust, or worry your as off everytime you go out.
  • Tiger02's avatar
    Tiger02
    Explorer
    Jun 02, 2017
    You need to check the wires to the Vehicle Speed Sensor (VSS) and the sensor itself. The VSS sits on top of the rear differential. Sometimes it help to pull it out and clean it up if there is gunk on it interfering with the signal.

    You most likely have a 4R100 transmission and in the F53 chassis for 99 it lacks the Output speed sensor (OSS) and the Input/Turbine speed sensor (TSS). One sits on top of the transmission and at the other at the rear if you have them.
  • chuckbear's avatar
    chuckbear
    Explorer
    Jun 02, 2017
    I would think that loose electrical connection not attached to the transmission would also show up elsewhere. I did check all connections to the transmission. Transmission was serviced and fluids replaced a month ago before we left for this trip. Chuck
  • rgatijnet1's avatar
    rgatijnet1
    Explorer III
    Jun 02, 2017
    It sounds like an electrical gremlin with one of the transmission or engine control modules. I used to have a few similar episodes with my coach until I took the time to disconnect EVERY electrical connection that I could find with the chassis, engine, transmission, and house circuits. I cleaned and coated each connector with dielectric grease as well as coating the spark plug boots. This grease is available at any auto parts stores and I have not had an intermittent electrical problem show up since then.
    As our coaches age, and because of moisture and other environmental factors, our electrical connectors can start to fail. Electrical problems, especially intermittent problems, can be very difficult to find and expensive to have a shop mechanic troubleshoot. I feel the dielectric grease makes sense as a preventative measure.
  • Busskipper's avatar
    Busskipper
    Explorer
    Jun 02, 2017
    chuckbear wrote:
    While driving on some local back roads we had a strange thing happen. We had been driving for a few hours that day and are into about a month of our current U.S. tour. Only doing 35 to 40 MPH and on hilly roads we suddenly lost the speedometer. Shortly thereafter while going up a small hill the transmission acted like it shifted itself into neutral. Shifting into drive 2 did nothing but downshifting into low gear, drive 1, downshifted the transmission and it shifted OK in drive for a while. Then suddenly it happened again. I have an SCT device connected to the OBD and the transmission was not showing above average temps and no error codes came up. We found a spot to pull over and check things. Fluid levels were right on and nothing appeared to be loose or disconnected. Just for grins, I reinstalled the 5 Star Tune and the speedometer came back and for the last few days, the transmission has behaved itself. But in the back of my mind every day, I worry about another episode. Has anyone else had something like this happen? 1999 F53 Bounder, V10. Chuck


    1999 - F53 - when was the last time you flushed the Transmission?

    My old 2000 was fine till about 50K then started to act up Flushed it ran fine till we sold it 3 years later.

    Just a thought,

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