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Cat M-Series Cab Doors

Nige · 2013-03-30 10:43

Does anyone have any experience of the M-Series graders cracking cab door windows..? We have had 4 or 5 to date over a 3-year period. Operator jumps down, closes the door, and the window cracks. A right pane in the ass because they are bonded windows and take time to replace and for the bonding to harden before the machine can go back to work again. Obviously with the change from H to M the windows have gone from 2 smaller panes of glass to one large one and the door structure surely must have become weaker as a result. Certainly as far as I can see the door frame on the M series does not appear to be made from heavier material than the H to counter the removal of the bar in the centre of the door. I'd be interested to hear if anyone else has had the same experience.

Replies18
  1. #1smoothoperator2013-03-30 11:43

    We have 140M's and an M2. Mine was the first with unexplained cracks in the door glass. Our salesman talked to their service dept. ,and both doors were updated from glue in to conventional lock in weatherstrip. At that time, it was done as a no cost update/product improvement/warranty item. Other machines have been updated, but it was done because of flying rocks or other objects hitting the glass. Parts departments may not know about the changes, but the service departments should. Good luck. smoothoperator

  2. #2Randy Krieg2013-03-30 13:45

    Nige Same here; our four year old 16M is on its 5th window. The fabricated door is too flexible. The thing that usually breaks ours is the door swinging open and strikes the catch (the latch which holds it open) to hard. I always tell the new operators never open the door facing the wind because that’s what usually gets them. The door is large, flexible and when the wind catches it, it’s a done deal. It will damn near break your wrist if you try to stop it once the wind catches it. I have seen G & H’s break the windows when striking the catch too hard also, but not nearly as bad as the early Ms. The Field Follow machine has a stamped door with zip in weather seal like the H Series holding the glass. The doors seal better and with 1600 hours on the SHM, no broken glass. I have asked if we can get these doors put on our older machine. Regards, Randy

  3. #3Nige2013-03-30 15:17

    Randy/Smooth Op, thanks for your replies. I've done some digging and there is documentation about parts being available to replace the OEM bonded windows with "old-style" zip-in seals. Whether it is a service program or simply an option available for customers to install at their expense I don't know yet, but I'll surely be finding out.

  4. #4smoothoperator2013-03-30 21:52

    The change/update is available as a kit. It includes a painted flat steel frame that is glued into the original window opening, slightly smaller glass with larger radius corners and curves, old style lock in weatherstrip, and a shorter wiper blade. I can post the p/n for the kit, but not for another 12 hours, when I get back to work and check the shipping box. I think the glued in steel stiffens the door frame, and the old style weatherstrip allows just a little "give" when the wind, your knee, or a pack of gum sitting on top of your checkbook in your left rear pocket impacts that big beautiful piece of glass. And never leave anything harder than a beachball on your floor when plowing snow or doing slope work. smoothoperator.....guilty of one of these things

  5. #5hotrod49er2013-03-31 22:46

    Make sure rubber stops are adjusted right. Stick out to much can bind the door when opened and n ot enough will cause door to slam againt the catch. And dont open any grader door in the wind either they break glass or your hand.

  6. #6smoothoperator2013-04-01 08:56

    I found the part number for the window repair kit. I think this was for the right side, so part number would be different for left side. P/N 352 4102 smoothoperator

  7. #7Nige2013-04-01 09:39

    Thanks for that. According to the documentation I've got our 16M's need 2 x 351-4101 kits (the 140M uses the 351-4102 Kit). A kit contains the material for 1 door only and the same Part Number of kit fits both LH & RH doors. The Cat Special Instruction for installing the kit is document reference REHS4389 in case anyone's interested.

  8. #8smoothoperator2013-04-01 16:59

    I'm sure the windows are identical as far as shape, but I wonder if there is actually an inside and outside to the glass? UV reflectivity, or maybe what type of glass is used inside/outside of the laminated glass panel? Just wondering. smoothoperator

  9. #9Nige2013-04-01 17:11

    According to the list of parts that comes in the kit there is just one part number for the glass, so it must be capable of being installed in either side.

  10. #10smoothoperator2013-04-01 17:20

    Good to know, thanks! Another glass related question-Why don't they use a laminated panel on the rear window too? I was plowing a couple of weeks ago, and got one of those wild flying rocks bouncing off of my ripper or wing strut, and it hit the rear window right on the glue seal area at the top edge. Sounded like a gunshot. Window shattered. I was told that laminated glass is cheaper than tempered, but is there a safety issue, or what?

  11. #11oregon96pd2013-04-02 20:04

    Isn't there a window shattering escape tool standard in the M's? (Hint Hint) :tong

  12. #12smoothoperator2013-04-02 21:05

    Yes, combined with a seatbelt cutting tool. I guess I will have to find some other way of keeping the flying rocks from getting me. I have 6 fenders, (plastic, Superior brand), but the rocks seem to find my windows anyway. Our Bobcat brand skid steer has pull tabs on the front and rear glass panels, and no emergency glass breaking tool. But those windows are not glued in. Thanks for reminding me about the reason for the glass and tool. smoothoperator.....in case of emergency, break glass

  13. #13Nige2013-04-03 07:18

    The reason the glass shattering tool was put there in the first place was that when the M Series graders first came on the market they only had one opening door (LH) as standard, the RH door did not have an opening mechanism unless the customer specified it (an extra at additional cost). Therefore to comply with laws requiring a 2nd point of egress from the cab the "Glass smasher" was installed. If the cab is equipped with 2 opening doors as I read it the glass smasher is unecessary. About 2 years after the M series came on the market Cat went back to 2 opening doors as standard, I guess because everyone was ordering them that way.

  14. #14Tinkerer2013-04-03 07:40

    http://www2.dupont.com/SafetyGlass/en_US/sales_support/technical-faqs.html#fourteen I replaced all my backhoe windows with laminated glass. I was worried that I made a mistake for not using laminated glass in regards to the safety issue. I did some reading on the DuPont website and it set my mind at ease. The following is a copy and paste from their web site. ----Can laminated glass be used everywhere that tempered glass can be used for safety and security glass minimum requirements? Yes, both laminated and tempered glasses are suitable for use in safety glazing applications. When glass retention or a persistent weather barrier is desired, such as in burglar- or storm-resistant applications, only laminated glass offers the added security of maintaining protection after glass fracture. -- If anyone would care to read about safety glass in detail here is the DuPont web address. http://www2.dupont.com/SafetyGlass/en_US/sales_support/technical-faqs.html#fourteen

  15. #15smoothoperator2013-04-03 14:07

    I e-mailed the DuPont website last night, asking several questions about laminated vs. tempered, hoping for some info and advice. I'm a small fish in a big pond, so we'll see if I get a response. Lots of good comments and input on this subject. smoothoperator

  16. #16Nige2013-04-03 14:26

    I suspect that if you were to ask them the specific question if tempered glass can be replaced by laminated glass in a vehicle/machine window that also needs to function as an emergency exit for the driver/passengers of said vehicle their reply might be somewhat different because laminated glass can't be broken as easily in the event of an emergency the way you can break tempered glass.

  17. #17buckshot_862013-04-04 00:54

    Nige, our 14 H's also have the glass smasher in them along with the M's. Some 627 G's, a D6 and an 815 also have them. I just assumed it was part of a new safety regulation with newer machines. I also did not realize that some of the early M's only had a single door. A couple of our 14's are 2008's, they must have been optioned with the dual doors.

  18. #18Nige2013-04-04 07:20

    The M series always had 2 cab doors right from the get-go. However if you looked closely at the RH door you would often find a machine where there was no door handle on the outside or inside, and in place of the door lock on the inside of the RH door there was a mechanism that held the door permanently closed on the striker. When I arrived where I am now in 2008 there were already 2 x new 16M's on the way to us, specced up by people who knew nothing about machinery. When they arrived Ops & Maintenance almost had a heart attack when we found that they had only 1 cab door that opened. Changing the RH door to an opening one did not take much either in parts or labour, so that's what we did even before they went to work. Later (about 2010 I think) Cat changed to 2 opening doors as standard.