John Deere 2650 Gearbox noise

[britcivic]

So, been using the 2650 with the clunky gearbox, until the rrr rrr rrr noise that I was hoping was just normal for reverse, got louder and started showing itself under load in low box and reverse, but not high box.

So, as clutch was suspect anyway I took the plunge and took the cab off (after taking roof off the shed to get enough height!), split at the clutch, then at the transmission, and tracked the grumble down to the lower hollow driveshaft, so (this has taken a while) all to bits now,

found some very flat needle rollers on the engine end of the shaft!

Have found the parts on the john deere epc, and the needle rollers aren't too pricey.

But the shaft surface and the inner surface of the hollow shaft are marked/pitted a bit - will a new bearing be ok - or do I need to do something more drastic?

 

[Dog&stick]

If its going to be in your possession for a time, I'd say ul have spend few more pennys, common fault on earlier 50 series.
I'd fit new PTO & fwd seals now you gone that far aswell.

 

[thesilentone]

More drastic I'm afraid, however I think you know that.

Is there an engineer in your area that metal sprays ?

If so, they will machine a small ammount off both surfaces, build it up, then machine it back to the right size.

Fitting a new bearing onto those surfaces is not an option.

 

[britcivic]

Having studied it a bit more, I can replace the race on the inner shaft, I presume it's a heat it off and on job.
The pitting on the inside of the hollow shaft doesn't feel too bad to my fingernail.... I'm wondering if another second hand shaft would be any better, or is this marking/pitting the usual?

 

[thesilentone]

As everything appears to be in one piece despite the pitting, are you sure this was the cause of the rattle and rrrrr ?

Was/is there much play when they are assembled ?

 

[britcivic]

Yes, I would have thought, there was a hell of a rumble when you span it by hand even. Definitely movement in it too.
trying to decide if this was also the cause of the clunky gearshifts..... clutch paddles are like new, about 0.25mm wear in the flywheel and pressure plate, but flywheel measuring undersize - think it was machined before last clutch fitted...

 

[britcivic]

Well, found a second hand back end, and swapped all the gearset and bearings over, set preload and backlash as per the manual. Couldn't measure 1/2Nm rolling drag on the countershaft, but set the preload as per the manual for a 2140, which doesn't mention measuring rolling drag anyway..

Only things I forgot to order were the orings for the transmission cup (plastic one), but the pipes slipped in nicely - is it critical to replace these before the rockshaft cover goes back on?

Have been through the EPC and put all the seals I can see into my basket for the HiLo, PTO clutch and transmission pump - are there any critical ones or other wearing parts I might have missed? Can't bring myself to put it back together without checking the trans pump first although it looks like a bit of hassle to get to....

 

[britcivic]

The 'Tractor shed' !

 

[davidroberts30]

50 series back ends NEED to be right, as your this far in change everything you can

 

[britcivic]

So taking the above advice I've pulled and stripped the HiLo, PTO clutch and brake and the transmission pump.

There's a fair bit of wear in there, good steps worn in the pair of hook rings in the HiLo, and the ring gaps look pretty big on the piston rings in the pto clutch and brake. Can't seem to find a spec for the ring gap - any ideas?
Mine are measuring between 0.5 and 0.25mm....

 

[Tractortech]

Now Then..
I've just looked through the TM and there's no spec relating to the rings you mention. If you think they're worn, fit new ones. The rings with hooks will wear a step on the outside edges as the pressure forces them sideways, I'd deffos fit new ones there. The piston seals of the Hi-Lo clutch and brake are a plastic (neoprene) material, change those too, early ones were a steel ring

 

[Tomr10]

Snap

 

[britcivic]

Thanks Tractortech - new rings it is then, should I file this wear away in the clutch pack basket?, or is it best left alone..?

 

[Tractortech]

Hmmmmm, it looks a little rough inside the drum there, most are but maybe not quite so rough. I wouldn't spend a lot of time. Maybe a quick rub with a file or emery tape. So long as it's smooth ish..

 

[NZ Tech]

Make sure the top shaft isn't moving front to rear. That makes the range levers kick back and forth off and on throttle quite badly and can give the synchronizers a hard time.

The 'Tractor shed' !

View attachment 989259

View attachment 989260

 

[britcivic]

Thanks TractorTech, good to know that a bit of wear is normal, I'll just take the burrs off and make sure the plates don't foul on the ridges i think.

NZ - top shaft shouldn't be moving as I have set 0.1mm preload on it, didn't measure the rolling drag though as don't have a torque wrench that goes down to 2Nm!

 

[britcivic]

Well, I tidied up the best of the two drums I had and reassembled with new piston ring and hook rings.
One thing is bothering me- I measured the two drums just to check they were the same.... and they're not quite.

My original drum has 'S' stamped on the face - is this related to the 'S' on the chassis plate (it's 40k), and did the 40k's have a different clutch drum?

 

[Tractortech]

You'd better read the parts catalogue for information. There are variations, depending upon the rear PTO output..

https://partscatalog.deere.com/jdrc/sidebyside/equipment/69588/referrer/navigation/pgId/186592173

By the way, you should have actual end float on the top shaft of 0.03 mm to 0.13 mm

 

[britcivic]

The EPC shows one drum for the independent PTO (AL39262) and another for handshift PTO (AL39263), depending on serial number, after S/N 652587 it's back to the same drum as the independent PTO (AL39262).

The problem I have is that the two drums I have have totally different part numbers to the above! (I was thinking they are related to casting patterns rather than drum part numbers?)

So, not being able to make any sense of that, I measured the two drums up. Outwardly they are identical, the only difference I could find is in how deeply the back of the drum has been machined, and therefore the volume of oil behind the piston - one is about 2mm deeper than the other.

I can't see how this would affect operation at all? -any thoughts on this - could it just be that the machining tolerance for this dimension is not critical?

 

[britcivic]

Well, spoke to Lee the oracle at Nick Young, and there are only 2 types of PTO clutch for the 50 series, -the one for 540rpm only is different - it has less clutch plates in it, so the big circlip fits lower down in the housing.
So I reckon the difference in mine is just in the machining, and so shouldn't affect how it works.

I'll let you know if I ever get it back together......!