Front Crossmember

Discussion in 'KK General Discussion' started by David13, Feb 22, 2021 at 1:18 PM.

  1. David13

    David13 Full Access Member

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    My front crossmember, under the transfer case is rusty. I want to replace it.

    It looks like moparwholesaleparts has it. $45. Not a bad price. For a new one.

    I suppose they will also have the bolts. They are rusty also.

    What about the nuts which appear to be welded into the frame? Will those be a problem? I suppose not as they should be sheltered from the wet and the rust.

    Most of the rust appears to be on the surface. It doesn't appear to be thru' like some have shown on some of the forums.

    So I don't think it's dangerous. I think it can wait til the later time of the trail season, which here ends around the end of October, or so.

    Anyone with experience, or ideas about this?

    Any tips on supporting the transfer case?

    Thanks
    dc
     
  2. LibertyTC

    LibertyTC Well-Known Member Staff Member Moderator

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    Photos would help. What was the part number?
    If it is simply surface rust it may just need a quick sand & re-painting?
    Use a ball peen hammer & hit it over the rusted areas. You should be able to tell if it's solid then or not.
     
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  3. David13

    David13 Full Access Member

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    https://www.moparfactoryparts.com/o...zNNsWMz_6NOEpr4pBpIKHCIcLwsws-EBoCG6IQAvD_BwE


    https://www.moparwholesaleparts.com/oem-parts/mopar-transmission-cross-member-52125442ad

    That looks 100% like it.

    I didn't want to bang it with a hammer. If it was too weak, it might fall.

    But I did think I'd poke it with an ice pick and see if it had any holes.

    But.

    Even the ice pick won't tell me what the percentage of metal left is. Has rust claimed 10% or 60%. I'm suspecting that from what I see so far, it's under 20% gone. So I think it's good for a season.

    But I do need to poke it to look for any holes. I can't see any. If I do find any holes then it may be more like 30% or 40% gone.

    I'd rather replace it than paint it. But I might put the POC15 on a new one.
    dc​
     
  4. David13

    David13 Full Access Member

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    There is also some type of bracket or such that sits under the transfer case on the crossmember. It has 3 or 4 bolts coming downward into the crossmember at the center point. That looks to have no rust on it, but the bolts are quite rusty. There I only want to replace the bolts.
    dc
     
  5. LibertyTC

    LibertyTC Well-Known Member Staff Member Moderator

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    Make sense^ It's too bad we don't have access to a KK parts fiche re that bracket. Hopefully a dealer can get you the bracket # & bolts.
    Overall the cross member is relatively inexpensive and necessary if it is rusted badly.
    Por15 sounds like a good plan for the new X-member for sure.

    I hate road SALT !!
    Luckily you are being pro-active, so I won't have to send you this sticker!
    [​IMG]
     
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  6. turblediesel

    turblediesel memberable

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    Use whatever blocks of wood and plywood to hold the transfer case up while you work on it. You can arrange them so they can act as levers to jack the weight up and down. I've pulled and replaced lots of transmissions this way without any jack.
     
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  7. David13

    David13 Full Access Member

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    I have gone thru' the parts catalog and that is the right number for the crossmember. But I don't see the bolts. There is no index on the parts list. Just 520 pages to thumb thru' to try to find anything.
    dc
     
  8. David13

    David13 Full Access Member

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    Well, I poked the crossmember with an ice pick. All very sold metal. Only surface rust.

    However, I have had a problem with what it might take to get it out. The 4 bolts coming down from the transmission mount are quite rusty. No idea if they would come off without breaking or coming loose from the mount. I see a mount listed in parts but some of them say it will fit my Jeep some say it won't.

    Also the bolts on the ends of the crossmember are rusty and if I need to replace those I can't seem to find them.

    I suppose those are rusty only on the head and wouldn't be a problem.

    However, my trans mount has 4 bolts going up, and the diagrams show only 3 on the mount. So maybe it wouldn't fit my Jeep.

    My Jeep originally was in Illinois, but then made it's way to Nevada, and specifically Henderson, Nevada, then Utah.
    dc
     
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  9. LibertyTC

    LibertyTC Well-Known Member Staff Member Moderator

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    The bolts heads do they have a mark on them? Are they grade 8?
    Does not sound like anything needs to be replaced, just sand/ paint or POR 15 involved then.
    Surface rust only is very good news!
     
  10. David13

    David13 Full Access Member

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    I don't know that I have ever seen bolts from a car factory (which I think those are) to have numbers on them. I could be wrong.

    I may be able to find the same bolts in a hardware store. With the number 8.

    I'm going to just let it ride at this time.

    I need to get back to the transfer case, front diff, and trans fluid. Then I'm happier driving it.

    I also got to borrow a tractor and get my neighbor to spread some of the gravel pile in my back yard around for trailer parking, after I go and buy the trailer.

    Anything I do is weather dependent at this time of year. Maybe we will start having some nice weather in a week or two. 59 for a high today, so it's already starting.
    dc

    I do like the idea of getting the crossmember off to wire brush and paint it, and check on the hardware.

    If I do that, for $45 I may as well replace it. But POR15 paint it first.
     
    Last edited: Feb 23, 2021 at 3:04 PM
  11. LibertyTC

    LibertyTC Well-Known Member Staff Member Moderator

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    Here is the way you can identity markings= bolt strength.
    [​IMG]
     
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  12. tommudd

    tommudd Moderator Staff Member Moderator

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    I've read through this 4 times, so its not the front cross member its the transmission cross member , correct ?
    If you want to replace it, easy enough to cut the bolts off if rusty, replace the cross member, use Grade 8 from hardware store to replace and be done
    Thinking too hard on a simple replacement
    Doesn't matter what Mopar used , if replacing with Grade 8 more than strong enough to hold it
    and you can not always go with what some diagrams show, they can be way off
     
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  13. David13

    David13 Full Access Member

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    I've never seen that before. I have seen the number 8 on some at the hardware store, in the number 8 bolts section.

    I'll check what's under there.

    Thanks
    dc
     
  14. David13

    David13 Full Access Member

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    Yes, my mistake in not correcting that. I actually thought it was the transfer case mount, but after looking I realize it was under the trans, not the trans case.

    It's actually mid ship. It's under the doors.

    I have since found that they call a part under the front bumper (or so) a crossmember also, or front crossmember.

    I know I could cut, etc., but, actually the bolts on the ends pass into the franme (?) or something and are probably not rusty inside there. And so should come out easy, and probably go back with no problem.

    The problem is the trans mount that sits on top of this crossmember and has 4 studs that point down and thru' the crossmember and have nuts on them. Those studs are somehow mounted in the trans mount above. If those break off, I have to get a new mount. And from what I'm seeing the mount they offer for sale has 3 bolts that pass upward and into the transmission csse. Mine has 4 going up.

    I'm looking in the stores for Liquid Wrench. I intent to soak those nuts and studs and see if I can take the crossmember off. And wire wheel it and paint it with POR15. Or just get a new one.

    I need to paint most of the underside of the entire Jeep.

    I know I'm over doing it. I always do it that way. That's why it's always a pleasure and a joy for me to do auto work. I know I could never make a living at it, and I have never had to. I have made money at it, tho. But I like to get it completely right, and understand it 100%. I got time. I can't get onto any trails in this weather. Most of the trails to the tops of the mountains here won't be open til at least April, or later. The snow machines are still out there roaming around. There is some serious snow out/up there. My house is at 5300 feet elevation, and the trails go up from here to 11,000 or more feet.

    I may well leave this crossmember and all the underside painting (POR15) til next winter.

    Thanks for your comments. I always appreciate them.
    dc