Pointers on buying a 720/730

[unimog_jason]

I've always had a bit of a thing for the old 2 cylinder diesels and one has come up for sale not far from me that has most of the stuff I'm interested in for what appears to be a decent price.

I've been hunting around for information on what to look for on these machines but haven't been able to find any sort of definitive buyers guide.

Based on what I've found so far the following seems to be true:

- Avoid the R and 70 as they don't have the centre crank bearing.
- The flywheel can become loose on the crank if the engine isn't shutdown correctly.
- If the electrical system has been messed with your batteries might be dead all the time.

Overall they seem to be a well built and respected tractor, but every machine has it's weakness. Anyone have anything to add to the list that would be specific to this model?

Jason

 

[sancwally]

Hi:
I'm currently rebuilding a 730 John Deere, and I can add a couple of things that I had to deal with:

-The electrical system was really messed up, generator was shot, the voltage regulator was gone, so I decided to install a brand new 24 volt alternator and rewire the entiry electrical system to a full 24 volt sytem.
-The gas lever had it's brake pads completely worn out, I used a clutch pad to replace those.
- The steering' bushing were also worn out, I had to remove them and take them to a milling machine shop, and had them remachined, and threw a couple of new bushings in the process..
- The generator base was broken, and it looks it was welded some time in the past also.
-All four tie rods ends where worn out, had to replace them.
- I'm pretty sure that the gearbox has an issue, the gears jumped back, it started with the 3rd gear, which my old man always used in the farm, he didn't fix that, he just started using the 4th gear .. I can't remember if that one died too.. also the reverse had the same problem.. so when testing one tractor you should go though the gears and see how it runs..

I think that's about it, the engine is solid as a rock, and cheap too... never had an issue with the cooling system..

oh, and check the hidraulic and diesel lines, they sometimes rub against the chasis and start leaking..

happy hunting!!

 

[unimog_jason]

Thanks for you input Walter.

Hope to go see the machine in couple weeks and see what it's all about. It will be subjected to a full battery of tests, I don't want to inherit another persons nightmare!!

Jason

 

[buickanddeere]

I've always had a bit of a thing for the old 2 cylinder diesels and one has come up for sale not far from me that has most of the stuff I'm interested in for what appears to be a decent price.

I've been hunting around for information on what to look for on these machines but haven't been able to find any sort of definitive buyers guide.

Based on what I've found so far the following seems to be true:

- Avoid the R and 70 as they don't have the centre crank bearing.
- The flywheel can become loose on the crank if the engine isn't shutdown correctly.
- If the electrical system has been messed with your batteries might be dead all the time.

Overall they seem to be a well built and respected tractor, but every machine has it's weakness. Anyone have anything to add to the list that would be specific to this model?

Jason

The 70 diesel certainly does have a three crank. An old two cylinder diesel can take $10,000plus in parts and labour. Loose flywheels and ruined crank splines are common if the previous mechanic didn't use a torque wrench. Lots didn't.