JD engine

[mikep]

Might be an idea to check the main drive pulley hub bolts are tight on the engine output shaft hub. As I remember there are two pulleys, the outer one is bolted into the main pulley, hiding the hub bolts. My pulley fell off once at speed after running rough.

Bearing behind the pully on the main drive number 9, remove the belts and check for any end float or up/down movement.
They use to ware the splines on the drive shaft also.
View attachment 693872

That is probably more likely then engine as the 'beat' is not really one I associate with them. Will give that a go.

 

[mikep]

Thanks for all the replies. Will know this week so will keep you posted.
Mikep

 

[Exfarmer]

Bearing behind the pully on the main drive number 9, remove the belts and check for any end float or up/down movement.
They use to ware the splines on the drive shaft also.
View attachment 693872

And knock the rivets out on plate 2

 

[mikep]

And knock the rivets out on plate 2

I had thsyt happen in my old 970 years ago really strange engine running but nowt else.

 

[TripleSix]

@mikep
It's not "thumping";out of the air intake is it?

If it is it's probably a valve not opening, broken or loose rocker, dislodged pushrod etc.

 

[mikep]

@mikep
It's not "thumping";out of the air intake is it?

If it is it's probably a valve not opening, broken or loose rocker, dislodged pushrod etc.

Hi no it's not that kind of beat it is much heavier whereas those valve symptoms are often more of a pop.

 

[Cowabunga]

Surely they wouldn't bother with a special block for the combine? That would be crazy I think. Low volume things usually get shelf parts.

I think the main difference in the combine and tractor engine of that model would have been a steel sump on the combine and a stressed load-bearing cast sump on the tractor. The combine might rev higher but internals would probably be the same. Exhaust manifold will possibly be different but that is not normally an issue.

Fairly sure a farmer not far from here sourced a combine engine to replace his knackered tractor engine. I do not recall that he had any issue changing the sump or any matching parts across from one block to the other. Both Saran engines. Turbo sixes. Not sure what tractor it was. Probably a 3650. It was a long time ago and it was only mentioned in passing when I saw the tractor when walking across his yard

Edit
On reflection, it is so long ago and the discussion so fleeting that I cannot vouch for the reliability of the above. I’m beginning to think it was a non turbo engine.

 

[mikep]

I think the main difference in the combine and tractor engine of that model would have been a steel sump on the combine and a stressed load-bearing cast sump on the tractor. The combine might rev higher but internals would probably be the same. Exhaust manifold will possibly be different but that is not normally an issue.

Fairly sure a farmer not far from here sourced a combine engine to replace his knackered tractor engine. I do not recall that he had any issue changing the sump or any matching parts across from one block to the other. Both Saran engines. Turbo sixes. Not sure what tractor it was. Probably a 3650. It was a long time ago and it was only mentioned in passing when I saw the tractor when walking across his yard

Edit
On reflection, it is so long ago and the discussion so fleeting that I cannot vouch for the reliability of the above. I’m beginning to think it was a non turbo engine.

Many years ago when the 40 series Deeres were current the farm I worked on had a cylinder head go not long out of warranty. The dealers fitted an ex combine head foc and it never had any problems.

 

[mikep]

Thanks for all the replies. Got it sorted now. It was a combination of belt/bearing slap from the traction belts and number 3 injector faulty. Together you couldn't identify the single problems. Took the belts off and half the noise went but still not right but with the belt noise silenced you could tell there was a missfire!! Just slacked off the injectors till no change and bingo. Must say is a bitch getting those little injectors or without the slide hammer adaptor. Anyway we had the siezed 975 engine so got one out of there and it's now as smooth as silk despite a slight overfuel on that cylinder
Now got another problem in another thread but may have cracked that as well.
Fingers crossed.