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D8K or D9N need advice!

Discussion in 'Dozers' started by bcole4, Dec 1, 2021.

  1. chidog

    chidog Well-Known Member

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    I just can not understand the crazy prices on all the old dozers. They have already paid many times for themselves, over the original cost from when brand new. They all have high time and likely fatigued parts, I have seen them with cracked out main frames. Then there are the jippo fixes on engine blocks, and things like welded transmission planetary carriers and the list goes on. Leaking at the rear plate caused by all the inner bevel gear case to rear plate welds cracked, I've seen it all. Its all just a lot of money for a pile of potential scrap IMO. The only old D8K's that maybe worth it are some of the ex military ones that show up on occasion.
     
    balls2go and bccat like this.
  2. bcole4

    bcole4 Well-Known Member

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    Hilo, HI
    had the same thought this morning minus the vacuum part. I put some jb weld on there so I could get through the day without dripping money on the ground as I go. Held up for the day at least.

    and yes it is a pinhole not a crack
     
  3. John C.

    John C. Senior Member

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    Likely a case of pushing lots of extremely hard and abrasive material. Lava does things like that.

    Make a steel patch, clean the area around the leak with ether and weld the patch over the top. Oil color I would guess is someone changed oil in the side that is clear. Left the old in the dirty looking side.

    She is tired is all. You probably paid close to what it is worth so you can expect those kinds of problems. If that is the worst so far, you are doing fine.
     
    oarwhat, nicky 68a and bcole4 like this.
  4. Check Break

    Check Break Senior Member

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    What color is your transmission fluid. Dark brown/black or yellow. Which final is which color. Black transmission fluid might indicate engine oil contamination. If it's getting into the final with the dark oil, that's the source of your color, otherwise, as said, the final with the dark oil is running oil with hours on it. If you transmission fluid is yellow, the final with the yellow fluid might have transmission oil in it that's leaking out at a fairly rapid rate, or it could just have clean 50wt in it.
     
  5. bcole4

    bcole4 Well-Known Member

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    thanks for the words of encouragement. I appreciate it
     
  6. bcole4

    bcole4 Well-Known Member

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    trans oil is yellow. Left side final is yellow out of the pin hole, wasn’t able to crack it open yet. Right side is overfull and dark brown/black
     
  7. nicky 68a

    nicky 68a Senior Member

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    Be careful not to overthink it and loose sleep.As John C says,it’s an old lady with various leaks and drips,stutters and stammers.Abit like an old Aunt.She’ll still be well capable of baking you a good batch of cookies though.
    Yes,your pin hole could be your pinion moving about abit over the last 50 years and that dowel acting up,but it’s most likely corrosion and old age.I’ve seen coal tractors rot around that area.
    Treat it like a scab on your elbow,keep it clean,patch it up,and change oil and filters in the finals.
    Keep a very close eye on the trans dipstick for a few months,especially if it’s parked up, and keep refilling the tranny until the finals have found their level.
    Try and enjoy playing with the old D8 as it will soon let you know if it’s sick,and in many cases,catching it early will only cause wallet stress sooner.I’ve had many old D8’s work with faults for years and years.
    Doing things by the book,will most likely bankrupt you on an old tractor,and it brings us right back to the start of the original post.
    We are all on a wing and a prayer with old kit and,quite frankly,new kit.
     
    oarwhat, JPV, 59 North and 7 others like this.
  8. bcole4

    bcole4 Well-Known Member

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    Thanks I appreciate it, since it’s new to me and the dozers are new to me in general I’m just having a harder time figuring out what is necessary to fix now, what can wait a while, and what is normal for this old girl.

    I appreciate you guys all taking the time to give your input
     
    nicky 68a likes this.
  9. bcole4

    bcole4 Well-Known Member

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    I think I found something that is very concerning now…

    checked the magnet for the trans and along with regular metal dust there is large pieces of what appear to be a bearing… I will post pictures in a bit when I get home.

    not sure how long it’s been in there, trans runs normal, nothing has changed from when I bought it at least.

    Is this a cease work order until I can pull trans and get a better look or if it’s been running ok so far can I continue on for now?
     
  10. nicky 68a

    nicky 68a Senior Member

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    Certainly pull the filters out and cut them open.
     
    John C. likes this.
  11. bcole4

    bcole4 Well-Known Member

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    A7EB1437-6545-4550-A7B5-143CFC22E66C.jpeg 1010F543-3015-4C06-BEDF-3B00C1EC277F.jpeg Here are some pictures of the bearing parts in the magnet. 3106D658-78A9-4613-BD4E-7352C9076945.jpeg
     
  12. Bluox

    Bluox Senior Member

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    As old Nicky says don't worry the old small stuff there are 29 more of those bearings in there.
    Bob
     
  13. bcole4

    bcole4 Well-Known Member

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    im not super concerned with the shavings and such but the large parts from the bearings I am.

    a friend told me that it could keep running like that for a long time or the next time you drive it it something major could explode inside the trans because the bearing is gone, so basically I have to do the labor of removing the trans and fixing it either way but if I do it now, it will be less money in parts.

    Thoughts?

    I have the machine at my ranch right now and I can pull and rebuild before continuing, I just don’t want to blow up the trans and have to completely rebuild if I don’t have to
     
  14. nicky 68a

    nicky 68a Senior Member

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    It’s not pretty.
    You’d like to think that the last time it failed,the screens were cleaned up.
    You have to look at the filters and cut them open.
     
    John C. and John Shipp like this.
  15. nicky 68a

    nicky 68a Senior Member

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    That’s the same filter out of one of my tractors that I’ve serviced last week.It’s suspiciously clean,but it does get tranny filters every 250 hours.
    I’m thinking you have abit of pain coming your way unfortunately.
    Allthough it’s little consolation,it hasn’t failed yet and could easily have happened to the D9N you were looking at.
    Allthough unlikely,it’s possible that the previous owner,or past owners haven’t bothered cleaning things out properly over the years after past failures.It does happen.
    I wish you luck,but cut your tranny filters open anyway.
     

    Attached Files:

  16. Nige

    Nige Senior Member

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    G..G..G..Granville.........!! Fetch your cloth.
    There's the issue. It would be a lot different if you knew that screen had been pulled and cleaned say 3 months before you bought the machine.
    Clean the magnets & screen, put the machine back to work, and see what accumulates on the magnet after 50 hours or so..?

    I do see a transmission overhaul at some point though, maybe sooner rather than later.

    The "half moon" and the other smaller similar piece are parts of a thrust washer (#27) from a planetary set inside the transmission.
    The needle rollers (#30) are probably from the same planetary gear that lost the thrust washer, likely the bearing failure took out the thrust washer. As mentioned above there are plenty of those bearings and washers in that transmission. The parts list says 42 of each but the illustration I found may not be exactly the same as your transmission.

    upload_2022-1-18_9-35-55.png
     
    JPV and ugis like this.
  17. bcole4

    bcole4 Well-Known Member

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    i called the seller he said that the last time he checked the magnet was about a year ago. He said he changed the trans filter about 3 or 4 months ago though so if I cut that open maybe I will get a little bit more info out of it.

    I did find a lead on a potential reman trans that someone has for sale. They told me it’s a new reman trans that they bought at a auction on Maui and it’s been sitting in one of there containers never installed. He said when he bought it, it had a tag that had the caterpillar logo and said D8k reman trans and had a little bag of gaskets for reinstalling it. He thinks that because it had cat logo it was a reman done by cat but someone else told me they never heard of a trade in program with cat for that sort of thing. Either way they want 8k for the trans, are willing to let me open it up to take a look inside, and give me a 1 week warranty.

    so my options right now are to rebuild my trans, run my trans until something else happens, or buy this trans and run mine until it totally breaks down and then swap this reman one in
     
  18. nicky 68a

    nicky 68a Senior Member

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    Can’t beat having a spare tranny about the place.
    You need to open the filters.
    8k is a good price for a tranny if it’s as described.
    It’s far better repairing a tranny that’s not failed with a bang.
     
    hseII, ugis, John C. and 3 others like this.
  19. Jonas302

    Jonas302 Senior Member

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    8 thousand would be a damn good price for a spare trans seems to me cat reman tags have some information serial # that might be traceable

    Yes Cat certainly handles exchange units so the story is plausible
     
    hseII likes this.
  20. tctractors

    tctractors Senior Member

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    First thing the air boost line from the inlet manifold to the Air Fuel Ratio Control means the engine has not been running correctly due to the rack travel of the injector pump being restricted, repair the line and run a stall speed test, the F/Drive with the sweat marks is most probably from damage caused by a rock or stone punching into the case as the frame moves about, this is not uncommon, the screen scrap iron thing is telling you of a fast coming rebuild job, don't think you can just stuff another transmission in the case and drive off as the lash on the Bevel Gear will need checking, if it's tight or to loose on the lash you will soon be into a nightmare, if you do pull the transmission out you might as well pull the torque out and check the bearings and the 2 shaft bushings for correct fitting, these bushings are often fitted back to front and effect the oil feed, the D8K transmission is not the same as the earlier D8H unit as it has an extra plate in the Forward pack (4 instead of 3), looks like 2 or 3 weeks of work ahead by yourself. tctractors
     
    JPV, 59 North, ugis and 7 others like this.