I'm looking at a D6C 10K. Can anyone tell me what year's they made the 6c model?

[DReiff62]

I'm going to look at a D6C 10K this week and wanted to ask about things to look for regarding this particular model. Were there any major issues with the C models that I should be aware of? I've heard a lot of good things about the 6c 10K but am trying to avoid buying a dozer that experienced operators would know to stay away from. Any info/advice regarding this dozer will be appreciated.
Thanks in advance for taking the time to share your knowledge.
Dan

 

[OzDozer]

An excellent little tractor, one of Caterpillars finest products. There are no major issues with this model tractor, unless it's been abused.
Fitted with the N/A, 4.75" bore 3306 engine, rated at 140 FHP, built from 1968 to 1977, available in Direct Drive or Powershift transmission.
Can be fitted with single, double or triple valve hydraulic system (#161, #162 or #163). Can be fitted with either straight bull blade (#6S) or angle blade (#6A). Can be fitted with rear mount #6 ripper.

Look for damage to track frame area, broken bolts, leaks and cracks. Check for track toe-out, to find out if outer sprocket bearing is severely worn. The track frames splay out when wear in the outer hub bearing is severe.
Check the cooling system for good condition coolant, no corrosion, and no core blockages in the tubes. Recent head replacement with unpainted head shows head damage, either from overheating or a dropped valve.
Listen to the turbo on shutdown to see if you can hear the turbine or compressor wheels scraping on the housings. Check the turbo inlet & outlet to see if there's any sign of oil leakage from either side.

Get the engine properly warm (20 minutes work) and see if there's any unusual noises. Let it idle for a few minutes then open the throttle to see if there's any sign of blue smoke.
Make sure all the controls work properly and effectively. Make sure the powershift transmission goes in and out of gear cleanly, with no incorrect positioning of the gear lever. Check for wear in all operating linkages.
The gear lever linkage bushings wear and sometimes prevent proper gear selection. The brake pedal shaft needle bearings get dust in them and seize up, resulting in brake pedals that don't return properly and dragging brakes.

Check the transmission magnetic screen for metal and brake lining chunks. Drain a couple of cupfuls of oil from each final drive to check for metal particles.
Take a crowbar with you, and bar the top front of the sprocket back and forth, looking for looseness in the sprocket shaft bearings. Check for broken track recoil spring, these are expensive to replace.

 

[DReiff62]

Thanks OzDozer for taking the time to share your knowledge; I greatly appreciate it. One follow up question to your advice; is the transmission magnetic screen accessible from above or do you have to drop the pan's?
Dan

 

[OzDozer]

Dan - No, no need to drop any belly pans. The magnetic screen is readily accessible by removing the floorplate. If my memory hasn't failed me totally, it's on the LHS between the transmission and the chassis.
It's located in the suction line that runs between the transmission pump and the front lower part of the bevel gear housing (under the rear of the transmission).

Regards - Ron.

 

[tj_farmer]

you could also take a few samples of oil and send if off to a lab, alot of companies have same day service.

 

[D6c10K]

All good advice above....
Be sure to check the condition of tracks closely because to do complete track, roller, idler, & sprocket replacement could cost 1/2 what the machine cost.

 

[DReiff62]

Thanks to everyone for sharing your thoughts/knowledge. I'm on my way to check it out today.

 

[DReiff62]

One ? leads to another; how much oil should I be prepared to catch when I check the magnetic screen? As I mentioned before, I'm new to the dozer world so being able to ask someone who knows about them is priceless.
Thanks again!
Dan

 

[OzDozer]

You don't need to catch any oil. The magnetic screen is a cylinder with a square plate on top retained by 4 studs & nuts. Unscrew the 4 nuts, remove the plate and pull out the mesh screen and the magnets.
The magnets are circular and attached to a cylindrical metal frame that sits inside a cylindrical mesh screen. Remove the whole lot as one, then remove the magnet-containing metal frame from the mesh screen.
The magnets retain any metal particles and the mesh screen catches the big chunks of foreign material. You'll find small particles of brake lining, and other small debris in the screen, this is normal.
If there are largish chunks of anything, that's a cause for alarm. If the brake linings are worn right down and starting to break up, you'll find a lot of brake lining material in the screen.
The magnets are usually coated with a fine metal fur that is just metal particles from normal wear. If there are needle roller bearings breaking up in the transmission, you'll find larger chunks of bearing metal attached to the magnets.

 

[oldirt]

the oil in the mag screen body will drain back into the case. You will find some stuff, if it is plugged it could just be the trans pump. Was for me anyhow. Look into the top of the radiator to try to see how bad it is limed up. I have a 6D which is very similar to the 6C 10K, and that radiator was plugged severely and wasn't fixable. This is a must. Look at the motor with the RH side screen open and listen to see if there are any broken exhaust manifold bolts which blows the gasket. If it does, you will in all probability want to reman the whole head, along with a new manifold and new injectors unless these have been re'd recently. This is pretty common. Now that you are in there, shut off the motor and check the fan bearing to see how shot it is. Mine was completely gone along with the housing. Easy fix though. Talking to the owner extensively is a very good idea to get an idea what has been serviced when.

C's are a great tractor but they have dry steering clutches and the brakes do not have hydraulic boosters on them like the D series, and the pedal will push rather hard after a long day. The D's had the brake combined on the steering clutch lever so you hardly ever need to touch a brake at all. If I were looking again, I would bypass the C for D again. Direct injection motor on the later one is pretty nice too. good luck..

 

[Bob/Ont]

I get the drift you are also looking at a D7 too. Buy the D6, easier to move and still very productive. Undercarrage and final drives are your biggest cost after fuel. Make sure the idlers are not falling off the ends of the track frames, the sprocket tips are not sharp, the final drives hold clean oil not white oil full of water and the sprocket's can't be pryed sideways too much, more than an eight/sprocket spring at teeth. Check the mag screen in the trans pump suction line, make sure it will steer easy at low idle with trans oil up to temp.
Later Bob

 

[OzDozer]

C's are a great tractor but they have dry steering clutches

This is totally incorrect information. All D6C's, from the very first one produced in 1963, have oil steering clutches. Yes, the brakes are not power boosted - but I never found that a problem.

 

[lowbed driver]

How many different types of D6C's where there. I ran a 67-68 10K and a few 6c's made in the mid 70's but thought that they had a different serial #.They sure looked different that is for sure. The later ones looked bigger/heavier to me any ways. They were great dozers for sure. My first 6 that I ran was a D modle and that was after spending 2 weeks running a TD20 which was the first dozer I ran. Needless to say the 6D was a tad less productive then the 20 and my first impressions were "these suck". I mentioned this to the instructor and he said " you would be surprised at what a good cat skinner can do with a D6". Man was he right,those words have never left me. Great old machines.

 

[OzDozer]

There were 23 different S/No's of D6C. The first D6C was produced in 1963 and the last one came off the production line in 1977. They were available in direct drive and powershift, in ag models and with cable control and hydraulics.
They were extensively modified and upgraded over that period of production. The early models ('63 to '68) were fitted with the 120HP, 4.5" bore D330 engine - then in 1968, the naturally aspirated 4.75" bore D330C was fitted, still at 120HP.
This engine was turbocharged in 1970 to 140HP, and renamed the 3306 in 1972. The D6C gained weight with a substantial number of engineering upgrades and improvements that included improved final drive gears and improvements to the track frame area and other areas. A/C enclosed cabs became available in the mid-1970's. In 1977, the D6D replaced the D6C.

 

[lowbed driver]

I never did spend any amount of time on the D6D's so my choice may be biased but if given the choice I would take a late model C over a D. Just me. LD.

 

[oldirt]

well, sorry. I was wrong on the clutch issue. I think I told more than I knew.. Maybe your legs are stronger than mine if the non boosted brakes are not an issue there. I will defer!

 

[oldirt]

I wish I could delete some of what I write..!

 

[shopguy]

Hey oldirt will your 6D stay full of water ?,got one that never gets hot but pushes out a bit every day.

 

[DReiff62]

Bob/Ont, I'm stumped on the phrase "more than an eight/sprocket spring at teeth". Please explain this "dozer man" term to an ole KS dirt farmer!
Thanks,
Dan

 

[OzDozer]

Oldirt - I don't have any problem with people posting up erroneous information - we've all done that. However, like most people, I prefer to see errors corrected, particularly where the info is proveable.
I've found a double check, to make sure the factual info proffered is reasonably correct, is one good way of preventing "foot-in-mouth" disease! However "opinion" is always readily available, and is always free!

Maybe I was a whole lot younger, and whole lot stronger, when I owned D6C's? - it was between 40 and 46 yrs ago! However, I don't ever recall the brakes on the D6C's being hard on the leg muscles.
One thing I did find, was that the standard fit, nylon brake linings on the D6C weren't as effective (braking wise) - nor as long-lasting - as the optional metallic woven linings.
So - every time the original linings wore out, I replaced them with the metallic woven linings. These linings gave improved braking performance and lasted longer, at the expense of some clutch drum wear.