| Author |
 Topic Search  Topic Options
|
Chitwoodshan 
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
 Post Options
 Thanks(0)
 Quote  Reply
 Topic: HD7G (B) engine rebuild D3500
Posted: 09 Feb 2012 at 1:12pm |
|
Hey Guys, I'm getting ready to pull the engine out of my 7g. Can anyone tell me should I break it apart behind torque converter, or does engine come out seperately or is it a pump on back of engine? I've worked on trucks but never heavy equipment. I'm going to rebuild the engine. I haven't pulled the oil pan yet but intend to do so before I pull the engine. I think I have a spun main. If the crank is in good shape I could do an inframe. I plan on taking pics an posting/asking questions as I go. Any help from yall will be greatly appreciated.
|
 |
|
Sponsored Links
|
|
|
gemdozer
Orange Level
Joined: 17 Sep 2009
Points: 942
|
Post Options
Thanks(0)
Quote Reply
Posted: 09 Feb 2012 at 3:21pm |
|
You pull motor with torque
|
|
Dozer
Orange Level
Joined: 16 Aug 2011
Location: SW New York
Points: 689
|
Post Options
Thanks(0)
Quote Reply
Posted: 09 Feb 2012 at 4:44pm |
|
I have all of the manuals if you need any pages copied. If you have the 4 cylinder engine. I have an extra crankshaft all standard except #4 rod journal that will require welding. If you would like to purchase my extra crank make an offer. Remember they are heavy so they cost a lot to ship. If you decide to get yours rebuilt tell me who can do it and how much they charge. I suggest you drop the pan to check out the crankshaft before pulling the engine. Find out which of the 2 types of thrust bearing you have. Standard bearing shells should be 0.12475 - 0.12525 if they are 0.010, 0.020, 0.030, or 0.040 thicker the crankshaft has been cut. I have seen cranks where all of the journals have been welded so don't get discouraged. Locate your bearings before having your crankshaft serviced. The 6 cylinder bearings fit on the 4 cylinder. There have been some government surplus AC 7000 motors on eBay that would be less expensive if yours is too far gone.
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 09 Feb 2012 at 7:20pm |
|
Thanks Dozer, Mine is a 6 cylinder turbo, I have an operators manual and parts manual, but no service manual. I'm pretty sure I have a 3500 engine. I know you have a lot of experince with the 6g and I don't think there is a lot of difference other than size. I'm going to try and rebuild it myself. I've rebuilt 7 or 8 gas burners and 1 diesel a (standard 23c) 4 cylinder on a Fergason to35 tractor. I'll keep you posted I hope to get oil pan of Fri, or Sat.
|
|
D-17_Dave
Orange Level
Joined: 11 Sep 2009
Location: Mocksville NC
Points: 990
|
Post Options
Thanks(0)
Quote Reply
Posted: 09 Feb 2012 at 7:40pm |
|
If the rod bearing is spun you'll need to pull the crank out to repair. Anything less will be a waste and you'll be back into it.
|
|
Yea, I can fix that.....
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 09 Feb 2012 at 8:01pm |
|
Hey Dave, I understand that any damage to the crank requires it to be reground. I guess I'm just hoping it will be ok
|
|
gemdozer
Orange Level
Joined: 17 Sep 2009
Points: 942
|
Post Options
Thanks(0)
Quote Reply
Posted: 10 Feb 2012 at 5:57am |
The ALLIS CHALMERS 7GB has a 6 cylinder motor 3500
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 10 Feb 2012 at 8:26am |
|
Thanks Gemdozer, I thought it was a 3500. Does anyone know where I can get a shop manual or something for the 3500 motor?
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 10 Feb 2012 at 8:51am |
|
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 10 Feb 2012 at 8:53am |
Here are some pics of my motor. Does it look like a 3500? 
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 10 Feb 2012 at 8:59am |
I had a heck of a time lifting the boom. I took the caps off of the cross over lines under the seat to releave the pressure. Then put a telephone pole on top of ROPS chained to rear and used the chain fall in picture along with my 753 bobcat to pick it up. It was slow going and heavy! Ater I got it up I put caps back on an decided to put trees under it for safety
|
|
Rawleigh
Orange Level
Joined: 14 Sep 2009
Location: White Stone, VA
Points: 421
|
Post Options
Thanks(0)
Quote Reply
Posted: 10 Feb 2012 at 11:46am |
|
The trees may slip. The proper way is to cut two pieces of heavy angle iron to lay on top off the cylinder rods and then lower the bucket down until they are captured. Just be safe! That thing can kill you in a second if it comes down.
|
|
gemdozer
Orange Level
Joined: 17 Sep 2009
Points: 942
|
Post Options
Thanks(0)
Quote Reply
Posted: 10 Feb 2012 at 12:48pm |
|
Maybe you can have manual in this site or binderbook.com or jensales .com
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 10 Feb 2012 at 4:58pm |
Thanks Rawleigh, I'll put some angle iron on those cylinder arms. I think we have some heavy stuff with 3" leg. The chain fall was holding it and I shoved the trees under it with the bobcat. I appreciate all the advise I can get. I'm going to try and pull the oil pan tomorrow around noon.
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 11 Feb 2012 at 12:51pm |
|
Update: I drained the crankcase today and got 8 gallons of diesel and fuel! Has anyone ever run into this before? I was talking to my father-inlaw and about the only way for fuel to get into the crankcase is by the rings. I didn't get to pull the oil pan the wife called with a higher priorty project. Any suggestions or info helpful. Thanks Guys.
|
|
Dozer
Orange Level
Joined: 16 Aug 2011
Location: SW New York
Points: 689
|
Post Options
Thanks(0)
Quote Reply
Posted: 11 Feb 2012 at 6:07pm |
|
I wonder if the motor is hydraulicly locked with fuel. Maybe you have a broken injector rather than a bad crankshaft.
|
|
scott
Orange Level Access
Joined: 12 Sep 2009
Location: michigan
Points: 2434
|
Post Options
Thanks(0)
Quote Reply
Posted: 11 Feb 2012 at 6:22pm |
ought to be clean inside...
|
|
DrAllis
Orange Level Access
Joined: 12 Sep 2009
Points: 19508
|
Post Options
Thanks(0)
Quote Reply
Posted: 11 Feb 2012 at 8:46pm |
|
Shaft seals on the injection pump can allow fuel into the crankcase. If the crankshaft has spun a main or rod bearing and the crankshaft journal is discolored, the crank is probably junk.
|
|
SteveM C/IL
Orange Level Access
Joined: 12 Sep 2009
Location: Shelbyville IL
Points: 7981
|
Post Options
Thanks(0)
Quote Reply
Posted: 12 Feb 2012 at 10:11pm |
|
3500 for sure.DR is right. Inj pump likely culprit
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 13 Feb 2012 at 10:45am |
|
How do I check the inj. seals? Pull the front cover off and see if fuel is leaking there?
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 14 Feb 2012 at 11:17am |
Pulled center main cap off and bearing was spun. This is picture of crank. When I run my finger nail across it its not as bad as it looks in the photo.
Now I have to pull the motor. Can I put fuel in the fuel tank and watch the front of the fuel pump to see if its just leaking out or does the pump only leak out when its running? Thanks for all your help
|
|
DrAllis
Orange Level Access
Joined: 12 Sep 2009
Points: 19508
|
Post Options
Thanks(1)
Quote Reply
Posted: 14 Feb 2012 at 5:41pm |
|
At a MINIMUM replace the seals on the driveshaft to the injection pump AND go thru the injectors as well to make sure there aren't any bad ones. You might want to consider having the inj pump overhauled while it's off the engine to be able to replace the driveshaft bushing which the seals run against.
|
|
AC 3500
Bronze Level
Joined: 24 Feb 2012
Points: 10
|
Post Options
Thanks(0)
Quote Reply
Posted: 24 Feb 2012 at 5:06pm |
Hi all,
New member, first post. Thanks for having me at your group.
Thats a tough looking dozer! Like the other posters said, be careful with that bucket, that looks like one of the worlds' larger and toughest mouse trap / man traps in that position! Looks like it would kill a person instantly, or worse. 
Good luck with your repairs, I'll be following along with interest. I have a project going involving an AC 3500, too. I may end up with an extra AC3500 engine that I could sell, its from gov't storage, and it looks like it was overhauled by a gov't facility in Oregon in 2006, and stored since then, not been run. If it doesn't work out to be economical to repair your engine, get in touch.
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 24 Feb 2012 at 8:19pm |
|
Thanks, What kind of money would you be thinking on that motor if it doesn't work for you?
|
|
AC 3500
Bronze Level
Joined: 24 Feb 2012
Points: 10
|
Post Options
Thanks(0)
Quote Reply
Posted: 25 Feb 2012 at 10:57am |
Seeing as how those trees are making me nervous, I'd look favorably on an offer of $2500. for it.
I'm in Texas, but think I may have a trip to make in that direction (sort of), might be able to bring it as far as Asheville, NC for $250. or so, expense money, don't know if thats a good deal, you may be able to get it shipped all the way to your place cheaper, what with all those shipping wars and everything going on. I think it weighs 1800 lbs., or so I've read.
It's on a wooden pallet / stand / skid. I believe it was intended for a military generator (maybe 60 or 80 kva unit), and I don't know about the applicability, except that its a 3500, made in the early 80s'. Some of the paperwork with it indicates it makes 167 horsepower, how does that match up with the specs for your dozer?
Might need some adaptation to your intended use, maybe bellhousing / flywheel etc., might need to be swapped out, etc? Not turn key, but might provide a leg up for your project dozer.
No guarantees, but I think they go all the way through them at those facilities, so should be new bearings fitted on polished journals, etc., and / or overhauled accessories like the turbo, starter, alternator, water and fuel pumps, injectors and so on. Probably should have some cleaning and confidence checking to correct or rule out any potential problems from storage, that task would be your responsibility, if you decide to buy it, as I would be selling it 'as-is'.
Might be worth considering this engine if your present engine is going to be too costly to feasibly repair.
Let me know if you're interested, if so, I can provide more info., if you're not interested, I don't want to clutter up your thread any more than I have.
Thanks.
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 25 Feb 2012 at 12:43pm |
|
No Problem AC, I really want know what I'm going to do until I get the motor pulled and torn apart. How long till your trip to Ashville?
|
|
AC 3500
Bronze Level
Joined: 24 Feb 2012
Points: 10
|
Post Options
Thanks(0)
Quote Reply
Posted: 26 Feb 2012 at 4:38pm |
Hey Chit,
Not sure when I'm gong to NC, but probably a couple of weeks out, at the soonest, and don't know for sure that I'll get to go, just yet.
Let us know what you find when you get her out and apart.
Meantime, here's a couple pics, see how similar (or not) they look.
|
|
Chitwoodshan
Bronze Level
Joined: 25 Aug 2011
Location: Hartwell GA.
Points: 23
|
Post Options
Thanks(0)
Quote Reply
Posted: 04 Mar 2012 at 9:09pm |
|
Hey AC. Sorry for the delay I've got my engine almost ready to pull my engine. But I'm considering your engine also. Do you have any more pics and info like how long it's been sitting /stored. What part of Texas?
|
|
Steve allis dozer
Silver Level Access
Joined: 10 Apr 2011
Location: Australia
Points: 232
|
Post Options
Thanks(0)
Quote Reply
Posted: 04 Mar 2012 at 10:02pm |
That engine on the pallet sounds like a good deal to me , considering prices snowball once you start tearing an engine down , I just spent over ten grand on a hd11 engine rebuild and a lot of running around looking for hard to get parts and I still have to do somthing with the turbo!! Just my two cents regards steve
|
|
AC 3500
Bronze Level
Joined: 24 Feb 2012
Points: 10
|
Post Options
Thanks(0)
Quote Reply
Posted: 04 Mar 2012 at 11:11pm |
Hi Guys,
I'm in North Central Texas, 50 miles or so North of Dallas / Fort Worth area along I35.
I believe it was overhauled in 2006, stored since then, the fellow at the yard where I got it said he had removed it from the crate just before I picked it up.
There is a card with it , I believe, signed by the fellow responsible for the work, and a little other info., I'll try to add some more pics tomorrow. The tag on the side says the crank is std on mains and rods, IIRC.
I may be going to Asheville, NC in the next week to 10 days.
Chit, if you don't want it, and anyone else here has interest, especially if they're along that TX to NC route, get in touch. The shipping can be a real deal breaker on something heavy and large like this, and its rare I'm on a long trip with trailer and space on same.
Thanks.
|
|
