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
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.
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
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.
you could also take a few samples of oil and send if off to a lab, alot of companies have same day service.
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.
Thanks to everyone for sharing your thoughts/knowledge. I'm on my way to check it out today.
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
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.
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..
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
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.
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.
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.
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.
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!
I wish I could delete some of what I write..!
Hey oldirt will your 6D stay full of water ?,got one that never gets hot but pushes out a bit every day.
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
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.
Dan, I think you'll find that Bob/Ont meant to type - "more than an eighth (1/8") sprocket spring at teeth". In other words, if you pry the sprocket teeth and see more than 1/8" free movement at the teeth (generally accompanied by a "clunk-clunk" sound), then the sprocket bearings are loose and need tightening - or worse, they are failing. The sprocket shaft is a hollow tube that rotates around the fixed "dead axle". On each end of the sprocket shaft is a large taper roller bearing. These bearings need to have substantial preload on them at all times, applied by tightening the sprocket bearing adjusting nut. Failure to tighten the adjusting nut every 1000hrs, as recommended by Cat, results in loose bearings. Loose bearings can hammer under working conditions and will then fail within a shorter period of time than normal. Thus, keeping the preload on those bearings is a critical item of maintenance on the old Cats.
Okay DReiff, took me a bit to figure out what I was writing about. 1/8" sprocket movement at teeth is not bad but check down near the hub to see that it is most sprocket deflection, not hub movement. Hub movement should be very little. Hope this helps. Later Bob
Im not sure i understand how to do this check. Do you put a pry bar at the top of the sprocket and try and pry is away from the machine, like checking wheel bearings on a truck?
Yes, just pry against the solid cast section of the final drive housing, and see if you can get any sideways movement in the sprocket. It helps if you take any weight off the sprocket by parking on solid level ground, so the machines weight isn't sitting on the sprocket, as it can do if the ground is uneven. On a hard level surface, the sprocket has little to no tractor weight on it, as it is raised slightly above the level of the bottom track rollers.
A follow up on the D6C that I took a long road trip to inspect. The first thing was a skim of oil on top of the antifreeze in the radiator. The owner seemed as surprised as myself when we discovered it. Is the most likely cause a leaking oil cooler? The second thing was way more than 1/8 movement in the sprocket teeth when pryed out with a bar. Did not hear any clunking sound but must have been able to see at least 1/2 to 3/4 movement and it was not spring, you could clearly see the hub moving. One roller was off with bolts broke off up inside the frame, a second worn so bad that it was into the bearing hub, and both rear idler rollers (upper) were egg shaped; down to the bearing hub on one side and 1/2 inch on the other. The rail measured 4 and 1/4" tall at the back end; wondering what they measure when new? The bushing the rail pins go through where worn pretty badly but had not been turned; does anyone turn these anymore or just replace the rails? The idler's themselves seemed to have some life left in them, but the mounting assembly had a lot of play. They wobbled as the dozer moved, and when pry'd on you could raise them up and tilt them sideways more than an inch; it seemed excessive to me as a novice anyway. The serial number was 10k 2578; he said this is a 69 model and I'm wondering if anyone can verify this? It did not have a turbo. Thanks to all for your inputs; it was an interesting experience inspecting the machine with all your advice. The man said, "for your first dozer you sure seem to know what to look for"! Thanks for sharing your knowledge. Dan
well, thanks for pointing it out! I am all for correct info too. I wonder if the one I drove had the nylon brake linings, it took a good shove to lock up a side and I am 6'9" tall. What is the climate like in Perth? I always wished I could have visited Australia. Shopguy.. Mine loses zero coolant. Where do you see yours "pushing out"? This is something that shouldn't get away. If you see no wetness then it must be going out the exhaust stack. Or somebody is stealing it a little bit every day!
dreiff62..oil in the radiator probably came from a cracked head. cooler is a maybe, but probably not. The sprocket on a final should have zero movement. If it does the bearings are already loose and it all needs to come apart. If one is like that the other side is probably no different. It sounds to me like the complete undercarriage is shot, looking at about 10G for that. I wonder how wore out the dead shafts are where the c frame bolts up under the back of the tractor? Probably gone too, this is an old tractor, be glad you didn't get hooked into it. look for one that the owner has a repair history on all the components, so you will know what you can expect in your near future. This is worth more than any oil test to me, especially if they just changed all the fluids.
DReiff62 - Yes, the seller is correct on the year of build. That tractor would have the naturally aspirated, 4.75" bore, D330C engine. Oil on top of the antifreeze is almost certainly a leaking oil cooler. I have to disagree with oldirt - a cracked head will rarely put oil in the coolant, but it will put combustion bubbles in the coolant though. Heads crack in the combustion chamber area, not around oil galleries. A loose head would possibly leak oil into the coolant, but it would also be showing leaks on the outside of the head/block join line. The loose sprocket is a bad sign, although no clunking is a good sign. Extreme looseness is an indication that the sprocket shaft taper roller bearings are probably on their way out. A final drive overhaul is the likely scenario. However, to check for sure, draining some final drive oil and looking for taper roller bearing chunks is necessary. If there's identifiable roller chunks, the bearings are toast. If the final drive oil is pretty clean and the sprocket seals aren't leaking, you may be able to just tighten the adjusting nut, and save the sprocket shaft bearings. The undercarriage sounds pretty sad, and you'll be looking at a lot of $$'s to bring it up to good condition. Broken roller bolts are common, and a PIA to get out - but rollers worn down as badly as you describe is just poor maintenance. The top rollers (carrier rollers) get flats worn in them because lazy operators don't shovel out dirt buildup under them. The dirt buildup stops the rollers from turning, so the track chain just wears a flat on them. There were two sizes of track link available for this tractor, each with different rail heights. You should have gotten the link P/N. Links with P/No's of 7S9109 & 7S9110 have a new rail height of 4.65", and 100% worn (rebuild limit) is 4.27". Links with P/No's of 9M5627 & 9M5628 have a new rail height of 4.50" and 100% worn measurement is 4.12". On that basis, those rails are either totally shot or nearly totally shot. Very few owners turn pins and bushings any more because of the cost and the difficulty of finding track shops. In addition, bushings that are severely worn on the initial side cannot be turned. If you turn them, there is inadequate metal thickness left in the bushing because of the extreme wear on that first side - thus the turned bushings will shortly start to crack, break up, and fall to pieces. Idlers commonly get sloppy and wobble around because the manganese guide strips in the track frame and idler collars get severely worn, or they break off and fall out (they are tack-welded to the track frame and idler collars). Glad to hear you went in hard on the tractor inspection and made it look like you knew what you were about. That would make the owner realise he couldn't put one over you - and it also gives you a good idea what you're looking at. The tractor sounds very tired, and in need of a lot of money spent on it and suffering from poor maintenance. Unless you get it exceptionally cheap, and don't mind pouring the money into it to fix all the problems, you're better off to keep looking. Oldirt - Perth has a climate very similar to coastal Southern California, without the fogs! Cool, rainy Winters, with a warm drier Spring, and a hot dry Summer. The temperatures run between about 40°F to 60°F in Winter and 60°F to 100°F in Summer. Hilary Clinton rolled up for a talkfest last week and it was her first visit here, ever. She was very impressed with the beauty of Perth, the clean white sandy beaches, blue skies, and the fabulous bluey/green Indian ocean. She was so impressed with Perth and the surrounding areas attractive appearance, she wants to come back to visit on a vacation. Not a lot of Americans come to visit or live here, because we are just so far away. The diametrically opposite point on the globe to Perth, is a point a few hundred miles off the coast of SC! - just SE of Bermuda! http://www.antipodemap.com/
Sounds like a great place to live. One of my girls lives in San Diego, and it seems like everyone and their brother wants to live there. Crowded so bad it is not enjoyable. I defer again to your assessment of the oil in coolant, what I have seen must have been unusual. as to tightening the bearing preload on an already really old tractor with unknown hours on the final I would say this would probably get you out of the job you are in but that final needs to come apart.
Oil in the coolant is 99% from oil coolers. Clearer oil is transmission cooler [most likely cause anyway] darker engine oil cooler. Although from memory there is no engine oil cooler on this model, is a housing but is only a kennel, nothing inside it. Later turbocharged 140hp one have engine oil cooler. That much flop in sprocket hub, id say final drive bearings have been that hammered they are very close to failure anyway. And as Oz says about the carrrier rollers; man in the seat was pretty lazy, and alergic to grease guns too id say. This one sounds like it was much better left behind. Was alot of these early 125 hp ones around in the early days here; although japanese 69J versions. and were not particuarly liked, where prone to 'chuffing' getting carbon under valve seats. Opinion was the earlier 76A series went better than them. Of course the later 140hp 10K and 69j models were obviuosly the best. Keep looking mate !
Oil in the coolant is 99% from oil coolers. Clearer oil is transmission cooler [most likely cause anyway] darker engine oil cooler. Although from memory there is no engine oil cooler on this model, is a housing but is only a kennel, nothing inside it. Later turbocharged 140hp one have engine oil cooler. Cracked heads will blow bubbles and push coolant out of the radiator like farting in the bath. That much flop in sprocket hub, id say final drive bearings have been that hammered they are very close to failure anyway. And as Oz says about the carrrier rollers; man in the seat was pretty lazy, and alergic to grease guns too id say. This one sounds like it was much better left behind. Was alot of these early 125 hp ones around in the early days here; although japanese 69J versions. and were not particuarly liked, where prone to 'chuffing' getting carbon under valve seats. Opinion was the earlier 76A series went better than them. Of course the later 140hp 10K and 69j models were obviuosly the best. Keep looking mate !
Dreiff I think you might have hit a real fixerupper here. However if you take on this project and see it through you will have a great tractor with very few supprises. It needs final drives and a complete UC job. If you have the final drives apart, check the gears out good. If you are luckey you might fine that they have not been apart and if so the teeth will have heavy wear on one side only. Wash up and inspect the gears and reinstall them in the opposite side, if the gears have one good side they migt give you 80% life after swaping. Might be good to take the bevelgear shaft and clutches out to, at those hours the bearing behind the bevelgear is likely chipping up. Keep shims in place and if you rebearing they will likely be wthin one shim of spec. Once that is done a UC job done correctly needs the frame ends built up and ground and the wearstrips replaced. The collar strips aswell and the endplates built up and ground. The rubber covered springs and wearstrips alco need replacing. Then you can setup the frame and idler allignmment like new. The oil in rad should also put some water in a trans or engine. If not much do a head gasket, lube oil furrels and seals might be leaking oil into coolant. Later Bob
What does the 10k have that a regular D6C doesn't? What is a good price for one of these with a power angle and in good working order. There is one for sale up here with a direct drive transmission and is advertised as working good. Not sure on the U/C but by the pictures I'd guess >50%. I am not going to buy it, I am just curious about pricing. Its advertised at $6000 and owner says late 60's model.
Don't know that a D6c ever came with a PAT blade....straight or manual angle is all I've ever seen unless someone built an aftermarket one.
Sorry. That was meant to be power tilt. Looks like the blade is approx 12' wide and maybe 3 high. Has a canopy but no cab.
The 10K series D6C is a "regular D6C". There were 23 different S/No's in the D6C, starting from the 73A (powershift) and 74A (direct drive) series in 1963. Each S/N prefix denotes either the transmission type, the country of manufacture or the development in the model line. The 10K series replaced the 73A series, when the 73A was upgraded and improved. The tractor value is represented largely by the following items, in order of importance; 1. Condition of undercarriage. Excellent undercarriage = top $$'s; Worn out undercarriage = near scrap value. 2. Attachments. A bare tractor is worth the least, a tractor with a blade is worth more, a tractor with a blade and ripper is more more again. A tractor with hyd tilt blade, ripper and enclosed cab is worth the most. 3. Transmission type. A direct drive tractor is worth less than a powershift one, in most situations.