2640 rebuild

[Albert F]

I have a 2640 that has a lot of blow by so I assumed the rings are shot. I am trying to decide if I should do a complete rebuild or just the cylinder sleeves, pistons and rings. The tractor has about 3000 hours on a previous rebuild about 15 years ago. Also would you recommend using John Deere parts or is there an aftermarket that is just as good? I appreciate all your input. Thanks
 

[FrankinFla]

The 2640 uses a 4 cylinder engine with 2 balance shafts. The bearings the shafts run in should be replaced. Replacement requires removing the balance shafts. Not replacing the balance shaft bearings can be the reason for low oil pressure after a rebuid and can lead to major block damage when worn bearings spin in the block.
 

[Robert Major]

Hi
3000 hrs on a rebuild doesn't sound like a lot for a Deere motor to me everybody says they can be high hour tractors and not touched.

How hard does this tractor work and how regulars the servicing?, Im kinda wondering if the bores are glazed up and it needs a good hard days work to break the glaze. I have seen this with a few tractors before that don't run hot or just run round the yard/field and do light work.
I guess it also depends how good the rebuild was too. These are just my thoughts on it but you know whats in your yard.
Regards Robert
 

[Albert F]

Can the bearings for the balance shafts be done in frame or does it require a complete removal?
 

[Albert F]

The 3000 hrs was a guess. I received this tractor from my dad who had the motor rebuilt about 15 years ago, but since the rebuild the tach and hour meter have not worked so I was just guessing on the hrs. I know the tractor hasn't done hardly any hard work for a majority of those hours as my dad quit farming about 12 years ago. So you have my interest. Can you tell me anymore about getting it cleaned out, maybe like a special oil or anything to run through it to?
I also should mention the blow by is the worst at an idle as the oil seems to flow out the breather tube, but as the rpm's are increased it seems to disappear for the most part, but if you put your hand underneath the tube you still get a little oil on your hand, but nothing like when it was idling.
 

[buickanddeere]

If the oil pressure is decent. Just keep running her.
 

[Tx Jim]

[Tx Jim]

[tim s]

You "Can't" get the rear bearing out while it's in the tractor...also check your clean air connections ,if it is drawing dirty air in on the clean side it will break all the top rings,,quickly,,I use ether and spray around the pipes to check them, if you have a leak the rpm's will pick up.
 

[Jethro Lilley]

If Tim S is right and the engine is dusted then a rebuild is called for. If not, then it sounds like oil is coming by the rings for some reason. Either the oil ring is not working or the cylinder is glazed. You state that your guess is 3000 hours since a rebuild 15 yrs ago, and your dad ran it 3 yrs and reired. Then the tractor sat with minimal use for 12 yrs. One has to work a tractor for 15 years at 200 hrs per year to accumulate 3000 hrs. 200 hrs is a lot of work for a tractor that is probably not the primary tractor. Probably has a lot fewer hours on that rebuild. It took me 20 yrs to get 5500 hrs on my 2510 before I rebuilt it. Let's assume the cylinders have glazed for a minute... If the rebuild did not include proper scoring of the cylinder walls prior to installing pistons, head etc. and/or unburnt fuel/oil has glazed the cylinder walls to where the rings will not seat, then there is an easy trick to try that was done on my dad's D6 Caterpillar when it was new and suffering excessive oil consumption. A factory man came to the field dressed in a business suit and told dad to take the air filter off and start the engine. He then sprinkled some Bon-Ami (Ajax, Comet) into the air intake side of the engine, like one would salt a hamburger using his thumb and forefinger. He did this about three times over the span of a few seconds. He then allowed the engine to run a minute or so and told us to "Shut'er down and change the oil." The Cat immediately stopped losing oil. The Bon Ami broke the glaze on the cylinder walls allowing the rings to seat and the oil change removed all traces of the abrasive before harm came to the bearings. If Tim's test proves no RPM loss then the engine hasn't been "dusted" so try this... it's cheaper than rings and sleeves and if a rebuild was needed after all, what have you lost? 7 qts and a filter? Cheaper than a couple of grand for a rebuild.
 

[tim s]

This is all good advice,, I have forgotten about using Bon Ami, I heard about it from a friend of mine that had construction equipment,I have never used it yet..
 

[Tx Jim]

Yep JD's branch area service manager did the Bon-Ami thing back in the day.
 

[Albert F]

So this Bon-Ami stuff, is it available today or is comet and ajax the same stuff? I am anxious to give her a try as a tried the ether trick and saw no change in the rpm's. Thanks
 

[Jethro Lilley]

Google it. Use the original formula if you can.
 

[Jethro Lilley]

I believe I've seen it at True Value Hardware.