Bulldozer D7 resurrection


More biners!!!
Jul 31, 2005
near Atlanta
I have access to a CAT D7 bulldozer at our farm. It belongs to my (deceased) uncle...actually now belongs to my aunt...he retrieved it from the deep woods about 30 years ago and used it around his farm (across the road from our farm). Uncle Kenneth got too ill to mess with it and parked it. Fast forward to 10 years ago. Uncle Kenneth's family was glad to know that Alex and I were interested to see if we could get it running. Alex studied up on pony motors and how to start it, we greased it, drained the fuel tank, replaced hoses, got a new battery ($130 as I remember it!!) and he got it started. Worked great at first. Then we realized it would only basically turn right. He got a little left from it but it took all his strength to get that to work. It took a 20-acre field to get it turned around enough to return it to home.

We did more checking after that on steering, brakes, tracks, etc. but didn't come up with a good plan. So...it still sits where we left it 10 years ago. Now that I have an excavator that I'll be using to work on our 20-acre pond, I could find the D7 useful. But I'll need to find someone to take the lead...someone with big eqpt. experience. It sounds great to hear it run...wondering if it's worth it to try to resurrect it for real.

I have considered seeing if our Al @Al Smith here at the House wants to take a South GA vacation and be my mechanic to get this thing usable...or decide it is not worth it...paying proposition. I have a 180-year-old log cabin that is vacant and liveable right now...my most recent tenant (an anthropology professor!!! how crazy is that) just moved to Utah for his first job as a Professor of Anthropology. The cabin is in good shape, right next to a big fish pond...which has not been open to the public for over 30 years...only fished occasionally.

These are pictures of the log cabin over the years...the inside does not have all the items in the pictures right now...we had renters for about a year. This first girl liked some of the "stuff" but we took a lot out for her. She left, we had a nightmare renter, got shut of him after about 6 months, had one girl renter that in 3 months probably only stayed in the cabin 5 times (??) and then our professor. He is in his mid twenties, smart, handy, would have loved to have him stay there...but Utah called. So, the cabin is empty right now. I plan to fix it up again like WE like it and have it available for family and friends to use when they visit the farm. In the meantime, it might be whispering, "Al, are you there???"

Here is a video of what Alex and I were able to do....Al, this is a big, baited hook for you... :D

  • Thread Starter Thread Starter
  • #6
Probably...we had it started in a few hours back then, much quicker than I thought we would. It might be salvageable...I need someone like Al or an eqpt specialist down there to give it the once over.
Run it Gary. Reads like the left clutch/clutches aren’t releasing, maybe the disks are rusted to the shaft, I’m no equipment tech so take it with a grain of salt. Maybe trace the linkage from the lever down to an adjustment point, the clutches should release before the brake fully takes up. I’ve never seen the clutches and brakes on a old Cat, it might roach the brake if the clutches won’t release. Free information is worth what ya paid for it, sometimes. Don’t be real quick to give up on it. If nothing else you’ll get an education... heh

If you want to turn left pull the right lever and backup. :|:
That would be my advise, start tearing into it and see what is what. Get it turning and running, then start working the different systems fixing as needed as you go, or just redneck it enough to run at first so you don't drop a bunch right away. Maybe try to hunt down some literature on it, not sure what is out there but i imagine you can find something. Parts schematics, repair manuals, etc. If you need hydraulic stuff or similar i would try to source generic parts first, i know parts with cat stamped on them get expensive fast. If it comes to that hit me up, i might know a guy... won't be free of course but i might be able to help get stuff that you might have problems finding, since they still have parts for those sitting on a shelf here.
I have witnessed numerous resurrections of Caterpillar tractors, 4s through 8s, 30s to the 60s. Like the second coming of Christ. My gawd it's alive!

In practically every one if you can get the engine going then fill the finals with diesel fuel, start banging with sledge hammers and everything breaks loose.

Just a little solvent and brute force. Cat engineering is like the pyramids.
  • Thread Starter Thread Starter
  • #12
I do like the sound of that. Looking back at that video the more we drove it the better it seems to get. I think it needs a lot of Pblaster and solvents and lubrication and Hammer it a lot like you said and just shake stuff loose. I talked to Alex again about it today and I think we're going to give it another shot next time we're down there. There is an old timer down there that worked on my granddaddy's 1953 Case tractor recently and got some good work done with it. I'm going to ring him up and see if I can interest him in scoping it out for me too.
Don’t be surprised if the hydraulic cylinders start to weep. Sitting is the worst thing that can happen to equipment. Maybe Kyle can find some ol fart up his way that he can pick his brain. I wouldn’t drag my feet, them guys are disappearing.
  • Thread Starter Thread Starter
  • #14
Yep, there's some oldsters out there that I need to find. I found some good threads on our D7..it is a 17A model...at Yesterdays Tractors. Some knowledgeable folks pitching in on topics, it will be a good source of info.
I know several, including engineers now retired that likely worked on those, and worked with several that built them as well. Hundreds of the 2005 model year? (i would actually have to sit down and do math) d9 tru d11 carry radiator guards built by me lol. So get to digging, this will make some of their day if i call em up for this lol.
That one looks like it has hydraulic assist clutches .It should have dry clutches and if so there should be plugs to prevent water etc. from entering the clutch compartments .A classic old cure was filing the clutch chambers full of kerosene ,run back and forth then tie the clutch levers back and drain the kerosene and let it dry out .BTW I am far from an expert of on old iron I've just worked on a lot of it ..
What you have is a multiple friction disc type clutch much like a motorcycle clutch between the discs are drive plates that can rust to the friction discs .I've never worked on a D7 but I have operated a few decades ago but those had the old "arm strong " clutch levers .3T models ,65 horse power ,1940's vintage .I'm not certain if it does have hydraulic assist where the linkage adjustment might be but on the early D4's it was under the seat .Those could be out of adjustment .You Tube might have have something on those .Saying all that you cannot kill an old Caterpillar they were built like battle ships .You can buy replacement parts for any machine ever made from Caterpillar but you might not like the prices .There are bone yards all over the United States though if you can find them .
  • Thread Starter Thread Starter
  • #20
Good detail, Al...thanks. I have started scouring youtube again for D7 info/vids. I can use your lingo as part of a search string to get leads to specific videos. Thanks for weighing in. I'll keep y'all posted on how my search for a S. Georgia old iron guru works out.
More comments .While watching the vid clip I saw attacking the the idle wheel, front with a sledge hammer trying to get the track adjuster to move .Some times it takes a rose bud torch to heat it to get it to move .You be surprised how strong rust is .With even hydraulic adjusters you use a grease gun on the seals can blow out .Then you have two choices ,Either detrack it or come up with sleeves and use a big hydraulic jack to move the track .I had to do the later on a small Oliver OC-6 I resurrected a few years ago after it sat for 14 years and never moved .It's fine now .
  • Thread Starter Thread Starter
  • #22
We don't have a torch down there now...as we spend more time at the farm, I think we will be getting one. I just watched a rose bud heating a bar to straighten it out...I am sure my grandfather used to do stuff like that. His old shop has lots of evidence of fabricating, fixing and tearing stuff up. There is one chunk of chain stout enough to move a tank...or a dozer, I guess. :)
I would also recommend that if you are getting a torch, to just break down and get the good t rated hose, 100 foot, and then some quick connects. Rip the band aid off once, and then enjoy using a quality set that will last damn near forever. I like the koike style quick connects, made by generac i think. That way you can quickly detach the torch, change to a different torch if needed, but mainly it's so much easier to wind up without the torch on there. The t rated hose is good for propane, so that can save you money on acetylene, and is handy for burning weeds and lighting fires 100 feet away from the bottles. 16313850329466250769111371408382.jpg
Last edited: