Third time hauling this one in:

[1693TA]

I pulled the back half outside so it could be pressure washed well to get rid of accumulated mud, dirt, and accumulated grease:



it was then pushed back into the work stall and will be torn down tomorrow. The mechanic actually doing the work has done them in the past and doesn't think this will be a problem as long as the case is good.

I'll post more on it later.

 

[56wrench]

I wonder in that tractor if they still used that torque limiter on the flywheel like the older 7060's etc with the power director?

 

[1693TA]

I wonder in that tractor if they still used that torque limiter on the flywheel like the older 7060's etc with the power director?

I do not believe so.

 

[ChuckRock]

Oh Trivoli, blink and you'll miss it! This brings me back, I spent 12 years working for the big yellow tractor factory.

 

[1693TA]

Oh Trivoli, blink and you'll miss it! This brings me back, I spent 12 years working for the big yellow tractor factory.

Yup, small town and small ways.

The area has several families with the surname "Rock". Are you one?

 

[ChuckRock]

Yup, small town and small ways.

The area has several families with the surname "Rock". Are you one?

No sir, it is what I keep between the ears!

 

[1693TA]

No sir, it is what I keep between the ears!

Oh, at least you have something there.
In fact my wife says the two names that fit me best are: "Null & Void".....

 

[1693TA]

Powershift transmission is broken apart and as suspected, the case is bad. A bearing preload locking nut backed off allowing mainshaft support bearings to lose preload and allow the mainshaft to move fore and aft in the case. This choked off oil flow starving the rotating shaft areas of flow till steel sealing and rotating rings welded themselves to their respective grooves. Ultimately, the case is worn badly. A request for a dimensioned drawing of the main case has been requested through Agco and if this can be obtained, the hole center can be located by triangulation and the part bored, then bushed back down to correct size. A replacement case, or remanufactured unit are also option(s), but none in the stocking warehouse. A used transmission is also an option but the owner doesn't want to exercise that option until other options have exhausted.

The input or main shaft will need replaced as will several rather consumable parts from wear. All the friction clutch discs appear to be good with exception of some have a steep ramp worn into their driven teeth. I've taken several photos but need place them in category to not confuse.

More later.

 

[1693TA]

Here are some photo and commentary:

These are the main innards to the transmission:



All looks pretty good at this point.

This is the reverse section which was presenting no problems. The clutch plates have been replaced at some point in this section as they differ in appearance from the others. Parts manager thinks he remembers replacing these many years ago:



This is the center section of the main case and nothing really found wrong here:



This is the rear of the transmission case and input to the rear drive axle. Nothing wrong found here either:

 

[1693TA]

Even the oil in the rear section was found to be clean and devoid of any metal chunks:



This is one of the clutch baskets which are really in pretty sound shape:



Another clutch basket and no real damage here:



Sun gears and output shaft without damage:

 

[1693TA]

Damage to case from input shaft bearings losing preload allowing the shaft to "walk" in the bore. You can see the three pressure ports for the clutch packs on the left side. These were "choked off" disallowing oil flow causing the damage seen to the bore:



These are the sealing rings and welded themselves to the grooves on the input shaft:



In this photo you can see the bearing retainer, the bearing, and the nut which backed off and was digging into the bearing retainer:



Looking close one can see the deformation of the threads which probably started this failure:

 

[1693TA]

There is a gauge measuring where the driven, or driving teeth of the clutches are "go, no go" and these do not pass due to daylight showing through:



Another view of the input shaft and assembly. Shown is the rear bearing which is one of the two supporting the input shaft:



Local machine shop says they can do the restoration of the case but will require a dimensioned drawing to properly locate the bore centerline. A replacement case is also being sought from a "core buyer" but no reply on this yet.

The gent and family that own this tractor are very "in tune" with their equipment. At the first discovery of something going amiss, we were called to get it looked at.

 

[terex herder]

If I understand the pics correctly there is no print necessary, the bad bore is in line with the tapered bearing bore. Hopefully the lube holes are sealed with pipe plugs on the outside rather than those d*mn seal plugs with the ball bearing.

 

[1693TA]

If I understand the pics correctly there is no print necessary, the bad bore is in line with the tapered bearing bore. Hopefully the lube holes are sealed with pipe plugs on the outside rather than those d*mn seal plugs with the ball bearing.

No doubt you could install the bearing plates supporting the shaft, indicate off the same to find your centerline, and go from there. However telling practicality to a production machinist whom seemingly only understands drawings is difficult. If I knew the dimensions I could jot them down on a table napkin and that would suffice but to tell him to indicate off of an existing part is very difficult. He does very tight tolerance work but is not a repair shop much at all. His shop is usually taking raw castings or forgings and making new parts from them. Will not work for Caterpillar, but does for Komatsu which are both in Peoria.

I hate those damned driven ball bearing seals too. I don't know what this one has as really didn't look.

 

[1693TA]

A replacement case has been located and the jury is still out on the input shaft being available. It is not from Agco but two dealers in North America show it to be on their shelves so attempting to acquire the same. $7700.00 and some change for a reman unit.

The original case is not repairable I'm told. There is an oil gallery which floods the thrust bearings and their core borings are less than .100" from the original bore. I measured with a set of precision dividers and the bore is grooved just over .072" with Agco tech support advising against repair. Personally I believe it could be sleeved easy enough but what do I know.

For the cost of a replacement used case, I'd damned sure give it a whirl myself.

Here is a photo of the pressed in orifice or restrictor, (circled in yellow) for the thrust bearing lubricant:

 

[1693TA]

Machinist looked at the case and doesn't see a problem making a repair.

Like me he's not "too good" to do the job, but he has the machines and I don't.