ctsnowfighter wrote:

Scott,
There a a myrid of problems with freeze damage, many totally unseen until they manifest themselves.
Does this 3T have Starting Engine or has it been converted to Direct Electric?
Starting engines depend upon the main engines water pump to cool them, and as such use the same complete system. We had a 9G that had frozen, no question of the damages as the bottom tank of the radiator was gone. Nothing of note in the block but Starting Engine always made water in the oil. Internally, water jacket broke into the valve train area, crack leaked so as long as the engine was running - water was forced into the starting engine, filling the crankcase.

RE: Parting out, do some research!! NOTHING on these is light in weight and a lot of the final drive assembly, dead shaft, etc require specialized tooling.
Caterpillar dealers had 100 ton specialized porta-powers with specialized tooling for pulling and repressing sprockets for example.
If memory serves me correctly, pulling the steering clutches and bevel gear requires access through a small hole on outside of case to reach the bolts, this requires the machine to be moved forward or backward as necessary to reach all the bolts.
Re working track chains is a specialized job too, takes specialized tooling and press to remove pins and bushing, then replacing same.
Unlike Military Track - Caterpillar comes apart at one location, either the Master Link/Pin or in later years, an alligator section of rail.

In short, there is nothing easy or light about tackling major repairs or parting out a D7!

If you do not have one - I would suggest an A frame with track and chain hoist on transverse top bar, rollers, at minimum, wide enough to span the tractor easily and on solid wheels.

Good luck - be safe.
CTS

Well, I do have the heavy duty 2 ton Harbor Freight engine hoist, so I should be fine!  

The 3T has been converted to electric start.

Thanks for the info!

Scott

the 3T looks like the crack is below the water jacket, if it is I would run it that way

caterpillar13 wrote:

the 3T looks like the crack is below the water jacket, if it is I would run it that way

Thanks for the input.

Scott

yes cast can be welded but it has to be heated to the proper temp first. and peened to stress relive it and so on.

another method is lock stitching where a series of holes are drilled for pins or locks and they are inserted and then they drill in between those put more inserts in. the company is in California called lock n stitch and they will do it for you either you send it to them or for big jobs they come to you or you can buy kits to do it your self
they only way to know is to pull it down clean it crack test it and go from there.

are you sure thats cracked and its not just the paint.

trainzkid88 wrote:

yes cast can be welded but it has to be heated to the proper temp first. and peened to stress relive it and so on.

another method is lock stitching where a series of holes are drilled for pins or locks and they are inserted and then they drill in between those put more inserts in. the company is in California called lock n stitch and they will do it for you either you send it to them or for big jobs they come to you or you can buy kits to do it your self
they only way to know is to pull it down clean it crack test it and go from there.

are you sure thats cracked and its not just the paint.

Yes, I'm fairly familiar with the methods of repairing cast iron.  What I'm more interested in is whether this area on the block is one that can be welded or repaired.

It's a crack; you can clearly see the crack in the pictures where there's no paint.

Thanks 

yes it can be repaired. the real test is when you try and repair it. what can change that is has it cracked other stuff on the inside or not and the only way to know is dismantle the engine.

Hi, bulletpruf.
Pretty much any of the types of cracks can be welded - if you know what you are doing. How-wevver, it does raise a couple of 'kwestyuns':

1. What caused the crack in the first place? Which brings its own follow-up 'kwestyun': Has what caused it been fixed?

2. Can it be welded satisfactorily without dis-assembling the engine and cleaning ALL the accumulated oil and 'gunk' (Don'tchya LURRRVE that technical term?) off the inside of the block?

Neither oil nor carbon deposits contribute anything good to a welding job.

Just my 0.02.

That crack is below coolant level. It has been hit from the inside, HARD. If it runs well that means what hit it has been fixed. Now it will just leak oil. I would clean it to bare metal, rough it up and then apply a coat of Devcon.

Deas wrote:

Hi, bulletpruf.
Pretty much any of the types of cracks can be welded - if you know what you are doing. How-wevver, it does raise a couple of 'kwestyuns':

1. What caused the crack in the first place? Which brings its own follow-up 'kwestyun': Has what caused it been fixed?

2. Can it be welded satisfactorily without dis-assembling the engine and cleaning ALL the accumulated oil and 'gunk' (Don'tchya LURRRVE that technical term?) off the inside of the block?

Neither oil nor carbon deposits contribute anything good to a welding job.

Just my 0.02.

All good questions.  I was operating under the assumption that this was freeze damage, but it's certainly possible that there was internal damage and it got fixed.  I asked the seller.

Thanks

 

kracked1 wrote:

That crack is below coolant level. It has been hit from the inside, HARD. If it runs well that means what hit it has been fixed. Now it will just leak oil. I would clean it to bare metal, rough it up and then apply a coat of Devcon.

Yeah, that's interesting.  As mentioned above, I just assumed freeze damage, but something is not adding up here.  We'll see what the seller says.

Thanks