Hello folks. This Sunday I'm hoping to look at a Caterpillar D 7C that is for sale. It has an electric start and the Serial No. is 17A5871 which supposedly is a 1956 machine made in Peoria. The transmission identification number I have been told is 4H8440. I have noticed there are a lot of low cost deals to be had on these two models - older D6's and D7's. Which of the two is the heaviest? It's not apparent to me when I search the internet. Which is more powerful? What little I know about this particular 7C is that it runs fine except one of the tracks won't engage when trying to make a turn (not sure what side doesn't turn). The owner says he thinks it's a linkage problem. If it turns out that it needs a new steering clutch, is that a repair that can be done by someone with little knowledge and experience in the maintenance and repair of bulldozers? The assumption is that I would seek out help when doing the repairs. Is this a difficult job? The other know fact is that this particular dozer comes with a straight blade without tilting capabilities. One of the things I am hoping to do with whatever dozer I end up buying, is to be able to push small to medium sized softwood stumps out of the ground. Will I be able to do that to some degree with a non-tilting blade on a D7C? Should I consider D6's as well? Any response would be appreciated!
The D7C that you are referring to or commonly called a D7 17a referring to the serial number prefix, should be about 128 horsepower. This machine if in working condition would be definitely capable of pushing stumps out. May have to dig around them some depending on size, but we have had a 17a for years and always served us well. They are a very well built machine. Steering clutches are pretty easy to rebuild. Slide the fuel tank off and take the covers off on top and a chain hoist will pull them up out of there after you unbolt them. A D6 with serial number 9u prefix of the same era is incomparably smaller. A D6C which is newer should be a powershift with around the same horsepower, but more dollars too.
Thanks for the response. The information you've given me is very helpful. I'm expecting to hear back from CAT Technical Support on the availability of parts and pricing. (I wonder how much the parts cost? ) I'm not sure I'll be able to line someone up to look at the D7 with me on Sunday. However before Sunday I hope to familiarize myself with what to look for with respect to inspecting the undercarriage. There must be references to that on the web? This could possibly be a good machine for me.
The rails should measure 4 5/8" tall when new. The sprockets on these machines aren't as beefy as a high track machine, and are more pointed when new than one would think. You will probably have to cut the sprockets off and weld the new style segmented sprocket ring on when you go to replace them if it hasn't already been done. http://www.tpaktopc.net/d7strcltch.htm try this site for steering clutch parts. I've bought brake liners from them before and like them better than the ones from cat. Most all of the normal parts are still available from cat. Also the 17a only turns at around 1200rpm wide open so expect it to sound slow. The lugging capability of this unit is unbelievable though. It will lug down to where you are counting hits and keep on going.
Alfred, the D7, came out with the 7S Straight Blade that tilts many years ago. If the blade on this 17A doesn't tilt, it must have been changed out to a much older blade. Check and see if it has turnbuckles attached near the top of the blade. If it does, then it will tilt. D6 Bo
Here is a photo and text from the ad of the D7 I will be looking at tomorrow. I plan on taking a number of photos tomorrow and posting them. I've seen a lot of photos of sagging tracks in my search for a dozer. That's not a good sign, right? The track in the photo appears straight. Is it reasonable to say that that is a good sign? The photos I'll take tomorrow should be revealing.
Great. Thanks for the tip. I'll keep you posted.
Yair . . . Alfred . If you are going to be doing dirt work or digging out stumps then trust me, a straight blade without hydraulic tilt is going to be a liability. Although a very simple concept it is difficult to explain just what a step forward this was in the productive capability and driveability of bulldozers. I am old enough to remember when they weren't around and I would rather run a stick shift with tilt than a power shift without, they really do make that much difference. They are easier on the tractor too as, when pushing dirt, (to some extent) you tend to steer with the tilt rather than the clutches. I might add that the most enjoyable tractor I ever ran was an early Sixties D7 with a cable blade, hydraulic rippers and tilt . . . one sweet machine. Cheers.
That's what I feared. I may have to leave this one alone. Thanks for the advice.
You can bet on needing all new plates, separators and frictions, for that steering clutch. When they freeze up like that they usually have several plates stuck together with rust, if they don't come loose they strip out at the splines, then there aren't enough plates working to hold the torque so they slip. Just a guess. Sometimes you can make a mechanical tilt into a hydraulic tilt, just takes a cylinder, a valve, some hoses and a bit of skill and head scratching. YMMV
I just got off the phone with the guy who is selling the D7. What an interesting guy. He's a merchant marine and his hobby is collecting bull dozers. He owns about 30 of them, and sold a D8 last week. He's got a root rake too, that supposedly fits the D7. I want the root rake. (I didn't ask him about a ripper - if he has one of those for the D7 I would love to have it.) And he's got another D7 with a tilt blade but I doubt I could afford it. I don't think I want to wait for the "right" dozer to come along. And I don't think I could afford the shipping if I were to buy out of state after finding a better bulldozer. At this moment my gut is telling me that I could do everything I need to do with D7 with the straight blade, but it may take longer and I will have to work harder at it. In about a months time the logging of my property will be finished. I really want to start working the ground as soon as I can. If I buy the D7 and fix the steering problem, then I'm ready to start working my land. If I don't buy it and don't find an alternative machine, then I'll have to wait and that's something I don't think I want to do. If the undercarriage looks good, if the motor sounds good, if there are no leaks, etc., etc., then I think I might go for it. On the other hand as I'm driving tomorrow morning down the coast of Maine sipping a Tim Horten's coffee, I may decide that everything I have just stated is bogus, and that I need to rethink everything. I'll keep you posted.
Tracks should sag a bit. Guesssing between .75- 1.5" sag If there overtightened, they can be hard on the idler bearings. Too much sag is a good way to spin out of a track
Yeah Alfred , The D7 with manual tilt blade would have no problem dealing with trees & stumps . I started out with a manual tilt cable blade HD 16 Allis . Crank the blade Over all the way & dig roots with the low corner of the cutting edge then shove over with the high corner . Later I converted the machine to electric over hydraulic tilt , made it allot handier for all around work . Deal with the Allis HD 16 fall through ?
Unfortunately yes. I was a little too late. That would have been such an awesome machine to have gotten. I've got my sites now on the D7. If for some reason the D7 I look at tomorrow doesn't work out, I think I'll stick to that particular brand (CAT) and model from the 1950's and possibly in to the 1960's vintages. The CAT has such a great reputation and parts are available, and the D7's of that era are affordable. I think it's a good fit considering everything.
I just wanted to mention that up where I live a John Deere 450 rents out at $2,200 per week or $4,780 for a month. And get this - they do not allow you to remove stumps with the dozer. Imagine that.
Keep looking at the D7 Cat's Alfred as they still have good parts support . Late 1960's D7E is my favorite Cat dozer , Aint nothin that dozer cant do . Pass on renting the 450 Deere dozer ........... Not enough tractor for what you need to do . The 180 / High horse Cat D7E would be a nice dozer for the job . They came in around 1969 & 70 . May have to open up the checkbook abit to buy a well maintained tractor as they hold value pretty good . My guess would be between 20 to 30 thousand for a nice High horse D7E .
Yair . . . Alfred . I have been showing my bias and leading you astray. td25c is right of course you can tilt the blade manually to get a corner under stumps . . . my problem is that our tractors were always getting trees and branches dropped across the tilt arms and they never really worked. Usually you could struggle enough turns to level the blade from angle left or right but seldom possible to get enough to make a difference. If for instance you had to get the corner in to dig a little ditch to push a broken down HD21 onto a float like this . . . (a common occurrence) we resorted to the old tactic of scraping up a mound of dirt or positioning a log to get the whole tractor tilted at an angle. Cheers.
Yeah Scrub , Good point . I remember having to keep the turnbuckles well lubed with grease and it would crank over pretty easy . Later I cut down a 4 " hydraulic cylinder & welded it in to the turnbuckle . Ran it off a self contained 12 volt pump unit . Mounted the toggle switch on the cable blade handle . It worked pretty good . Is that one of your old photos recovered after the flood ?
I think you should price out the possible cost of repair before you go too far.
Yair . . . Yes td25c . I have found a bloke who does some restoration at an affordable price and was curious how they would look on line. I have a few like that, just general "happy snaps" of nothing in particular but now, after a life time they evoke a certain nostalgia for an era and a way of life and a way of doing things we will never see again. That would have been a typical job in the red South-western border country. It was probably three or four thousand acres that had been ring-barked maybe just before WW1. The suckers were never bashed and many of the trees sprouted multiple stems and recovered. . . the only solution was to pull them. Nice piece of lateral thinking for the power-pack on your tilt system . . . I can imagine it was quite a revelation the first time you worked it and flipped that switch! (big grin) Cheers.
Yair . . . With apologies to Alfred for going O/T on his thread . . . this picture gives a good idea of why out tilt arms never turned. Cheers.
Could you elaborate.
I looked at the D7 today and went home feeling really good about this. However there were issues with the D7 that I'll explain in a little bit. First off let me say that the undercarriage looked pretty darn good. I knew nothing about undercarriage until the seller gave me a tutorial. The teeth on the sprockets were not rounded over. The thickness of the tracks were reasonably thick, the bushings or was it rollers (?) are still reasonably round in shape. The tops of the track segments were all raised with welded on extensions - see photo. The motor sounded great and didn't smoke. There was a small exhaust leak near the manifold that caused a little black soot to form. The hydraulics appeared to be in good condition. The blade hydraulics easily lifted the nose of the dozer on multiple attempts. There was a slight weeping of hydraulic fluid from one of the rams. The seller moved the dozer frontwards and backwards for many feet in distance and spun the dozer around in both directions. Apparently the track that had not been working was partially working. The seller seems to think that it's not an issue with the steering clutch but with the hydraulic assist part of the steering mechanism. The seller bulldozed a little of the ground in the immediate area and then used the blade to back spread the dirt. There was never really any attempt to lug the machine down with heavy dozing. We were in a large equipment yard that was literally filled with equipment and there was not much room for moving very far. One area of concern that I picked up on that the seller was not aware of until I pointed it out, was that there was transmission fluid or hydraulic fluid frothing out from a leak. The area of frothing appeared to come from underneath the floor where the floor meets the engine - very close to the starter. I wonder if the leak was connected to the hydraulic assisted steering mechanism? I have agreed to purchase the D7 for $4200. In addition I am getting a root rake that fits the D7 for $500. I would have taken a photo of the root rake but there was too much brush that had grown around it. We measured it and determined that it fits the D7 exactly. The root rake looks professionally made and extremely rugged.
Sprocket looks decent to me, the shoes have been "regrousered" as you say. The track links themselves appear fairly worn but not stretched out much, the bushings may have been turned. Probably work just fine for what you're doing. It does look like the idler is about to the end of the frame, so you may have to remove a link in the near future. My opinion, even if it needs some repairs, picking up a running D7 for less than five grand is a good buy on any day. YMMV
Thanks for the feedback, and educating me. I can't wait to start using it!
Thanks Scrub Puller. I'll probably try employing similar tactics moving stumps. Thanks for educating me, and the photo is pretty darn cool.
I really enjoyed this photo. What kind of dozer(s?) is that? What year?
Glad he was able to restore them , those are cool photo's Scrub . Second photo taken from airplane ? Seems like I remember you mentioning having parts & gear flown in at times .
Best of luck with the D7 Alfred . Sounds like you got a good deal on the dozer and rake .
Thanks td. I couldn't believe my luck when the guy told me he had a rake for the D7. And luckily the scrap price is high enough so that if all hell breaks loose, I won't loose my shirt.
Next thing to purchase is service & parts manuals for the D7 if they did not come with the tractor .
And I suppose after that filter(s) and fluids. There must be a ton of fluids in that rig.
Yair . . . Alfred . They are Allis Chalmers HD21's. the photo was probably taken in about 1963. Notice how there are logs and crap laying across the blades of both the inside and outside tractor. Some of that stuff comes down hard when those torque converter machines were cruising in light going like that . . . that's why we always had bent side arms. td25c . Yes mate taken from a 206 Cessna the only thing that allowed the company to stay solvent and eventually move on to Cats. Picture of her showing the decent cargo doors (you could get ten hundred twenty tyres in there) and a much younger yours truly here . . . . Cheers.
Cool stuff Scrub ! Love the picture of yourself loading the Cessna :thumbsup Did they let you fly it any ?
Yair . . . td25c . Plenty of "keep it straight and level" and basic turns and stuff. I would have liked to have learnt to fly but had little schooling and it was only in later life I acquired the math skills to handle navigation. I will not impose on Alfred's thread and start a new one with a couple of old photos . . . they are BandW snaps and not so good but may be of interest to some. Cheers.
These are new rails and new segmented sprockets for reference. Notice the distance between the front idler block and the end of the track frame. Your rails are about to the end of adjustment, but the sprockets look like new. The rails still can be used for quite a while, but when the pins and bushings start to wear the pitch gets longer and the sprocket has to pull the slack out when it goes around the sprocket which makes the sprockets wear faster. The pitch should measure 8" from center to center on the pins.
Thanks 7060 for the education. What did that cost you? Did you do the work yourself? If so was it difficult?
I just got 3 manuals online from John at tractorparts. There was a service manual ( over 300 pages), the operations manual, and the parts manual. I can't believe the amount of fluids this thing takes - a small fortune in fluids!
To be honest I can't remember exactly what it cost. It's been 3 years ago and this machine does a lot of setting since the d6r came along. I do all the service on them, and it's not too bad if you cut the old rails off. Those master pins are a pain. When you get new rails get them with a alligator master link. If you buy rails without pads, get yourself a 1" impact to take your pads off.
The machine that sets a lot, is that a D7? How old is it? Have you service the steering clutches before? Do you use the machines for work?
Yes this machine is a 17a just like the one you looked at, but mine is a d7d. Only main difference is that the D came with a factory turbo and lube for life rollers and the C didn't. 99% of the parts interchange. I believe mine is a 1959 model. Yes the steering clutches and brakes have been replaced too. The hydraulic assist unit sets under the fuel tank and fills at the back of the machine with 30wt oil. The only thing it does is makes the levers pull easier. The steering clutches adjust by turning the nut on the release fork inside the clutch housing, which can be done by removing the access cover. Mine still gets used occasionally, but I plan on repainting it and upgrading the hydraulics with a d7e pump and valve to give it tilt.
"The steering clutches adjust by turning the nut on the release fork inside the clutch housing, which can be done by removing the access cover." Can you explain this in a little more detail. When do you know to stop turning the nut?
The adjustment nut on the right side of the picture is the clutch adjustment nut. Your supposed to adjust them to where you have 3" of travel on the clutch levers when setting in the seat, but that's if the linkage isn't worn. As long as the clutch fork is somewhat loose with the levers forward you should be okay. You just don't want the nut too tight which will take pressure off the discs as if your pulling the lever and they will slip. If they are too loose the levers won't disengage the clutches. Notice the hairpin clip in the brake band adjuster to keep it from turning. The metal retainers wear which cause the brakes to vibrate and turn out of adjustment.
"The adjustment nut on the right side of the picture is the clutch adjustment nut. Your supposed to adjust them to where you have 3" of travel on the clutch levers when setting in the seat, but that's if the linkage isn't worn. As long as the clutch fork is somewhat loose with the levers forward you should be okay. You just don't want the nut too tight which will take pressure off the discs as if your pulling the lever and they will slip. If they are too loose the levers won't disengage the clutches. Notice the hairpin clip in the brake band adjuster to keep it from turning. The metal retainers wear which cause the brakes to vibrate and turn out of adjustment. " You should be a CAT maintenance and repair instructor! Thank you so much for the info. I think I'm getting ahead of myself though since I haven't actually got the dozer yet. It'll be a few weeks before it's delivered. Once the loggers are out I'll take delivery. And then I think the first order of business will be changing the fluids, filters and looking for that leak I noticed. Then possibly an attempt at adjusting the steering clutches if needed.
It finally happened! I took delivery of the D7 17A today, and the root rake. It took a while before we could actually move it off the low boy. But after a couple of phone calls to the seller we were able to start it up. Eventually we even put it to the test and stumped a few large stumps that were around 16" in diameter. When I say "we" I'm speaking of a friend of mine who has run dozers in the past. He was incredibly helpful and I'll be counting on him to teach me how to use this machine. If you remember I mentioned a potential steering clutch or linkage problem with the dozer. The right side track would engage partially and then eventually not at all. The seller mentioned that he believed it was a linkage issue and not a steering clutch problem. Just before the D7 was shipped to me the seller removed the fuel tank and seat to inspect the linkage and steering clutch. As he suspected the linkage was froze up - rusted. He mentioned that "pins" in the linkage needed to be removed and cleaned. At this point I have no visual as to what he was talking about but my intention is to remove the fuel tank and seat so that I can gain access to the linkage and make the necessary repairs. He went on to completely disconnect the linkage and fully engage the right side steering clutch so that the right track had power. However there was no longer a way to disengage it for steering purposes. But for the purposes of getting the D7 off the low boy, and for making the D7 usable, albeit in a sort of hamstrung way, we were able to actually put the D7 to the test by using it to remove stumps. I had been searching for a good video of a bulldozer removing stumps but haven't been able to find one. I hadn't formed a visual of a bulldozer removing stumps until today. For the past month or so I have been reading about those who swear by using an excavator to remove stumps, and those who swear by using a dozer to remove them. And after talking with the local heavy equipment folks, it was apparent there was a bias towards using an excavator. I remember reading though in a forum that the soil and ground conditions could play a role (as does the tree species) in the ease or lack of ease when removing stumps. That seemed to make sense to me at the time. Well I have to tell you I was so delighted today to see the D7 making short work of popping stumps out of the ground. The technique involved biting into the stump with the blade of the dozer, then gradually raising the blade coupled with forward motion of the dozer. It was truly amazing to see the stumps popping out of the ground in minutes so it seemed. My friend who was running the dozer today is of the opinion that I should stump with the root rake instead of the straight blade. I was wondering what you folks think about that. Al
I would think anything over 4" diam may be safer with the blade as it would be more bullet proof than the rake. I see the blade does not have tilt which is very beneficial when stumping. Where in Maine are you located, as I plan to be going through the state in the next day or so & may be close by.