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Front axle identification

Mike L · 2025-02-28 17:45

Working on this crane carrier which is essentially a truck frame that is driven by the crane mounted on top. King pins are shot. The tag is hard to read but it is a rockwell and the only numbers I can read is MAR 73 which I assume is March of 1973 and N932193. Is that helpful to anyone? If that doesn’t work, how else could I get the correct king pin kit? I have doubts that a parts guy can help just by Having the pin in hand or? Could there be a number stamped on the pin?

Replies6
  1. #1Truck Shop2025-02-28 17:56

    One big question--are the eyes in the axle beam good? And axle model number will have a prefix of FF.

  2. #2Mike L2025-02-28 18:13

    I have no idea. There is a chance that it’s fubar. The crane works everyday and it’s going to be tricky to get a time to down the machine.

  3. #3Truck Shop2025-02-28 18:37

    I made a correction FF prefix. Rockwell made several series, the FF931 is a very common 12,000 steer axle back in the 70's, also made FF941 and latter the very common FF961 rated 12.5 to 13K. But something few know--a kingpin set for the FF961 will also work in a FF931 axle with reusing the 931 kingpin covers.. I know because I've done it. * For the fact it has mag wheels and possibly other issues, it might {I say might} be easier to replace with good used axle, price and time wise.

  4. #4crane operator2025-03-02 09:09

    Got any more pictures of underneath, showing springs, steering set up, axle? Maybe a picture of the kingpin area where you could see the steering arm, and what everything looks like, then someone can identify it, by what it originally was. I kind of doubt its only a 12k axle, most any real crane carriers are built with heavy steers. Are they roading this around? I'm having a hard time seeing where shot king pins would be a problem if they are just weeble wobbling around a yard. But my last old 25 grove wasn't really safe for road travel any more either, so safety first! Here's the stemco book, it gives images of the pin styles and dimensions for all of them. Maybe start with the shaft and work backwards? (Old rockwell is now meritor). https://www.stemco.com/wp-content/uploads/2020/07/STEM1290_KaiserCatalogUpdate_v9r0_FNL_LR-spreads.pdf

  5. #5Truck Shop2025-03-02 09:30

    It doesn't have heavy cast dayton wheels, plus that's just a home brew.

  6. #6Mike L2025-03-02 11:07

    I don’t have any other pictures right now. These carriers are just like truck shop said- home brew. Most of them have hendrickson on the rear and a stack of springs on the front. It has a truck transmission that is driven by a hydraulic motor. To change the speed you just move the cut off shifter into another hole and go. Also they have hydraulic brake chambers that release when you move the travel joystick.