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D8K or D9N need advice!

firedozer

Active Member
Joined
Mar 27, 2008
Messages
34
Location
california
This is the problem in a nut shell, where do you stop? Transmission rebuilt check. Torq convertor rebuild ? Coolers cleaned? Bevel gear checked, adjusted, maybe repaired. And while we are there steering clutches and brakes.
This is the problem with old equipment. It becomes a money pit to get it right. And worst of all the value of the machine does not increase much.
I realize renting seems expensive, but it does have some advantages. You get the right machine for every job. My first machine was a D8K, I made that machine do work that would have been more cost effective with a different machine.
Even if you do all the labor and you have the tooling, parts are expensive for CAT parts. You can go non oem, but I for one have never had good luck going down that road.
 

Check Break

Senior Member
Joined
Jan 21, 2012
Messages
469
Location
USA
I would worry about damaging or causing further damage to the carrier within which the bearing failed. Those things aren't cheap. I kind of remember the Italians made one aftermarket. Otherwise, it's figuring out how to repair yours or buying a good used one. There's something to be said for digging in now before catastrophic failure. You'll spend a day or two cleaning the bevel gear compartment after a catastrophic failure, far less if you catch it early.
 

tctractors

Senior Member
Joined
Oct 9, 2007
Messages
2,412
Location
Worc U.K.
The thing that has possibly saved the day is the damaged air boost line, if the engine was getting full rack lift it would be sending big chunks of shrapnel into that magnet screen, on those screens you always get an amount of fine silt like wipe stains on a paper towel, but that screen in the picture looks like its fallen in a skip of engineers waste, a few more of those small rollers are just waiting to jamb between the the teeth in the back carrier (Most Probably), when you see that amount of junk hanging off the magnets it's a mighty good clue it's not break in fluff, the Transmission is 1 Job with checking the torque is more possibly a time thing with a gasket and a few O rings if your luck holds, the bevel gear lash needs to be checked more to establish it has some than anything, the pinion on the power shift is floating, the drain plugs under the steering clutch case are often blocked up with bits of band and junk and well worth cleaning out, it's a wet weather job and not really a bad job, steam cleaning things make the task a lot easier, best of luck that Man as he has 10 to 15 days of entertainment ahead, I would not buy anything until the bits are stripped right down and component checked. tctractors No second hand D8 or 9 ever comes in mint condition, they always want something off the new Master.
 

bcole4

Well-Known Member
Joined
May 6, 2020
Messages
122
Location
Hilo, HI
The thing that has possibly saved the day is the damaged air boost line, if the engine was getting full rack lift it would be sending big chunks of shrapnel into that magnet screen, on those screens you always get an amount of fine silt like wipe stains on a paper towel, but that screen in the picture looks like its fallen in a skip of engineers waste, a few more of those small rollers are just waiting to jamb between the the teeth in the back carrier (Most Probably), when you see that amount of junk hanging off the magnets it's a mighty good clue it's not break in fluff, the Transmission is 1 Job with checking the torque is more possibly a time thing with a gasket and a few O rings if your luck holds, the bevel gear lash needs to be checked more to establish it has some than anything, the pinion on the power shift is floating, the drain plugs under the steering clutch case are often blocked up with bits of band and junk and well worth cleaning out, it's a wet weather job and not really a bad job, steam cleaning things make the task a lot easier, best of luck that Man as he has 10 to 15 days of entertainment ahead, I would not buy anything until the bits are stripped right down and component checked. tctractors No second hand D8 or 9 ever comes in mint condition, they always want something off the new Master.

thank you for taking the time and giving me your input.

this forum really is an incredible place

right now my plan is to pull all the floor out, clean everything up real good, drop the trans pan, move the dozer 20’ to where I’m gonna drop the trans, take trans out and break it down to see what the damage is inside, then decide whether I’m gonna replace what I need to or look into the other reman trans

while it’s down I have some other TLC and paint I need to take care of on the old girl.

I appreciate everyone’s input and will keep you updated as things progress
 

bcole4

Well-Known Member
Joined
May 6, 2020
Messages
122
Location
Hilo, HI
One more question, for now….

any preferences on rolling the top back and pulling trans up vs driving up on blocks and dropping trans down then pulling out the back?
 

John C.

Senior Member
Joined
Jun 11, 2007
Messages
12,870
Location
Northwest
Occupation
Machinery & Equipment Appraiser
I usually took them out the top as I seem to recall they wouldn't clear the swing frames without pulling the torque converter. I also had a tire truck knuckle boom with a line that allowed that without having to pull the ROPS. Our friends with the different accents will probably let you know the best way.

Also with that kind of possible damage, I would recommend pulling the converter and having a look see.
 

nicky 68a

Senior Member
Joined
Apr 14, 2013
Messages
1,164
Location
england
As said above sir.
Top exit,and torque out same time.
Take a look at the engine mounts once you’re stood in the void.The right hand rear engine mount likes to migrate into the chassis abit.Not a big expensive issue to fix,yet it can cause your torque and tranny to run out of line if left unattended.
Please keep us updated.
Thanks for posting,and good luck
 

tctractors

Senior Member
Joined
Oct 9, 2007
Messages
2,412
Location
Worc U.K.
The Transmission needs to exit upwards, its a tight little job to tackle with the Cab off, I would never bother to even try with the Cab on, it would be the best idea if you stripped all the tread plates and any covers below the fuel tank off, then remove the seat with base plate and both belly pans to steam clean as much as possible, all the valves , pipe work and drive shaft have to be removed including the scavenge pump if you pull out the torque, allow a day in cleaning as the effort is well worth it, I always start the engine up and pump the trans' oil out with a hose hooked into the filter top, there is still lots left in but it's a lot easier to handle.
tctractors.
 

Check Break

Senior Member
Joined
Jan 21, 2012
Messages
469
Location
USA
Do you have a cab stop bracket like the one in this picture (below the left rear ROPS post) on your machine. You can tilt the ROPS or EROPS back and it will bottom out on this stop. Enables you to access the transmission and the brake covers. I don't remember doing a transmission without opening up the entire bevel gear compartment. Pull the fuel tank (clean it out while it's on the ground) and steering clutch covers. It's time to check the cross shaft, replace the brakes and probably pull the pinions and replace the duocone seals. A whole lot easier now when she's opened up. This also allows you to clean out the bevel gear compartment if there's more scrap iron (I like Tony's definition) in there.
 

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Shimmy1

Senior Member
Joined
Aug 14, 2014
Messages
4,350
Location
North Dakota
Is nobody going to tell this man he needs to stop right where he's at, snap a few pics, and hope nobody else on the island reads HEF? This IS going to escalate from a bad dream to a nightmare, and onward to a downright tragedy. Cut your losses, man. You finished your paying gig, quit while you are ahead. Just my $.02.
 

Delmer

Senior Member
Joined
Jan 3, 2013
Messages
8,889
Location
WI
Post #105 he says he's going to pull it forward 20' and take it apart, sounds reasonable to me.

NOW I get it, you're telling him to sell it as is. Depends on if he wants to be an operator, or if he want to learn how to work on an old Cat...
 

Shimmy1

Senior Member
Joined
Aug 14, 2014
Messages
4,350
Location
North Dakota
NOW I get it, you're telling him to sell it as is. Depends on if he wants to be an operator, or if he want to learn how to work on an old Cat...

I'm just trying to be a voice of reason, lol. Nothing wrong with learning how to work on old Cats.....this is going to be a VERY expensive and painful schooling, for everyone.
 

Check Break

Senior Member
Joined
Jan 21, 2012
Messages
469
Location
USA
Any way about it he's going to be working on a machine. The next one will do the same thing. There's something to be said for 7500 hour components you can rely on than those you know nothing about. Don't forget he's in Hawaii, there's a limited number of machines available, and the cost/logistics of shipping a machine to Hawaii these days is not what it used to be.
 

tctractors

Senior Member
Joined
Oct 9, 2007
Messages
2,412
Location
Worc U.K.
becole4, I could suggest that you look at an old line of mine in Shop Talk headed Caterpillar Sprocket Removal it's worth hunting through as it has lots of snaps of D8's Calved Down, tilting the Cab if it's a modular (EROPS) type is handy but it's only 2 more bolts to undo to lift it clear off, I never bothered to tilt them just lift away off the Tractor was my choice but we all do things different. tctractors
 

John C.

Senior Member
Joined
Jun 11, 2007
Messages
12,870
Location
Northwest
Occupation
Machinery & Equipment Appraiser
Beauty is in the eye of the beholder. Good business is in the pencil of the guy doing the figures and writing the checks. There was another guy on the island I think south of Kona that went through a D9 awhile back. The conversation went somewhere along the lines of it was cost effective to repair what he had against buying a different machine, maybe newer, but with the same risk of expensive repairs.
 

Bluox

Senior Member
Joined
Jun 19, 2010
Messages
1,960
Location
WA state
Is nobody going to tell this man he needs to stop right where he's at, snap a few pics, and hope nobody else on the island reads HEF? This IS going to escalate from a bad dream to a nightmare, and onward to a downright tragedy. Cut your losses, man. You finished your paying gig, quit while you are ahead. Just my $.02.
Shimmy,
you just can't resist can you .
Bob
 

Shimmy1

Senior Member
Joined
Aug 14, 2014
Messages
4,350
Location
North Dakota
Shimmy,
you just can't resist can you .
Bob
I know where you are going with this, but I'm not taking this position based on an assumption of capability. A recoil replacement is quite a bit different than what this 8 is going to require, both financially and complexity.
 

bcole4

Well-Known Member
Joined
May 6, 2020
Messages
122
Location
Hilo, HI
Do you have a cab stop bracket like the one in this picture (below the left rear ROPS post) on your machine. You can tilt the ROPS or EROPS back and it will bottom out on this stop. Enables you to access the transmission and the brake covers. I don't remember doing a transmission without opening up the entire bevel gear compartment. Pull the fuel tank (clean it out while it's on the ground) and steering clutch covers. It's time to check the cross shaft, replace the brakes and probably pull the pinions and replace the duocone seals. A whole lot easier now when she's opened up. This also allows you to clean out the bevel gear compartment if there's more scrap iron (I like Tony's definition) in there.

i don’t believe I do. Was told to roll it back and place a block between the canopy and ripper cylinder to rest it on.

I was planning on leaving brakes, and duocone seals for another time. Financially I can do transmission but don’t have a lot of wiggle room to do everything at the moment. In the future I know it will be work to open everything back up but it is a bad idea to not do everything now? It seems there is an endless amount of work that “can” be done, but as said before that will bankrupt before can get any work done
 
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