I had the driveshaft completely off before when I replaced the motor - never had the pin out though at the pump. I replaced the flexible disc coupling too. Didn't take the pin(s) out of any brake linkages either - rather I found a place to disconnect them somewhere else (would have to refer back to my pictures) so as to avoid hammering out a pin. In other words....I cheat...... Nice to know separation would not be necessary. I don't know...have to think about all this. I'd be more than content to let someone else tackle it this time since I so swamped with other things. Problem is..I need that 129 to run NOW....getting tired of trying to keep a few areas mowed (not even on my property...another long and sort of bizarre story) with just a weedwacker. So I was so pleased to finally be ready to go.

I like the idea of a video first before proceeding further unless it can be confirmed by my descriptions so far that indeed the hydro needs to be replaced and/or repaired. Well...repaired is likely a bit beyond my current experience level...crap...it'd probably be on my work bench for another 3 months.

Frank...I should have added that the noise occurs with the wheels on or off the floor - tried it both ways. One time almost started without any noise. I really question what's going on right inside the hydro where the trunnion is. Can something have disconnected in there? I moved it manually and can see that the shaft is turning on the opposite side, for whatever that's worth.

Thomas...been turning it by hand several times already - both at the front pulley and also right at the disc coupling...can hear these clicking noises as it rotates slowly and can see the trunnion (shaft tron?) sort of jerking with the shaft rotation.

I noticed also that I can pull on that trunnion shaft - where it goes into the hydro - and it really seems to pull in and out freely. Were it not for the rest of the linkages holding it all together I actually wonder if it'd pull right out of the housing? Probably not I suppose.

Sounds like the hydro might be toast !:bigthink:

Maybe dumb thought. If it were me. I would disconnect the shaft and try to start the engine. The last thing worked on was the engine. A bearing noise or other engine noise could easily sound like its coming from somewhere else. If nothing you could rule out any kind of engine issue by doing this.

Not sure who rebuilt your engine but it would not be the first time someone reassembled an engine out of spec.

Just a thought. I hope its something more simple than your thinking.

Coop....you must have been reading my mind also. This occurred to me as well. Is there enough room without actually moving the engine front to disconnect and get the shaft out of the way? When I took it off before I had already loosened the 4 oil pan bolts and shifted the engine slightly forward. Makes sense to use process of elimination, i.e. making sure the engine is ok. If it's not, that's on (or should be anyway), the builder...not me. The rebuilder is a lawn tractor dealer near me - guy has been working on these his whole life and so should know what he's doing. Certainly seems highly knowledgeable anyway.

I should also have added that the first time I started the engine, I was able to go forward and back with the tractor - no problem from the trans at all short of creeping forward when in N.

Thanks for the advice...I really can use as much help as possible on this one :) Thing is, though, if it is indeed an engine issue, why do I hear clicking noises that definitely seem to be coming from the trans when manually rotating the engine at the disc coupling?

I didn't need to hear that....but......unfortunately you might be right.

ok my turn.:biggrin2:
Did your hydro shift/control linkage somehow fall off the hydro and you are trying to start it in gear so to speak?
Those hydros will moan and get jerky if they are not in neutral position when starting.

They will also sound grindy.( is that a word?)
Move your hand control linkage and see if it is working the linkage on the hydro.
Don't get all discouraged,it ain't the end of the world and you are learning more than you ever believed you would!:beerchug:
Those hydros are dam near bullet proof.

LOL...was expecting you'd show up.

Wait...if the linkage "fell off the hydro"...where would it be? I mean, everything is in place..or are you referring to a disconnection internally somewhere? The shift lever (on the dash) is working the rest of the mechanism as it should. That being said, however, could it be that inside the hydro something changed so that indeed it's always 'in gear' at this point? There was less of the grinding (or whatever) noise if I didn't depress the brake pedal
quite as much, and then more of it when pressing all the way.

Just now I turned the motor by hand again and don't hear anything unusual on either end. Weird. Guess I'll try it again tomorrow morning and see what happens. I don't want to keep doing this though for fear of somehow damaging the engine. Got that right about learning more than I ever would have expected. I think I learned more in the past 2 years than in the entire 40+ years I've had the tractor.

Assuming this unusual amount of turning the motor manually doesn't do any harm? I always turn in the correct direction of rotation.

That's almost a direct quote that J-mech said to me awhile back when he was still around here, after I mentioned being cautious about putting in a new engine only to then have possible issues with the transmission. He said it was unlikely to happen, so I was encouraged by that and pursued getting another engine.

FWIW, As far as rotation, they are built for many applications and some are reverse rotation,
so no harm turning the other way.
The trunion linkage inside the hydro, is retained by a coiled pin in the swash plate.
I've seen them worn a tiny bit in the swash plate hole but never heard of one coming totally out of the hydro because of a broken coiled pin.
Those hydro's are avail used and usually about $100 if you actually have a bad one.:bigthink:

Sorry if this is obvious, but you did put oil in the engine, right? After the rebuild?

Coop is right, the hydro is pretty much bullet proof. You only pushed it a short distance, so not likely there is anything wrong with the hydro.

It sounds to me like your hydro is not in neutral while trying to start. It makes an awful squeal when you do this. Move the speed lever back and forth slowly while cranking the engine. At some point in the lever travel, you'll lose the squeal and the hydro will be in neutral. You may need to bypass the brake pedal safety switch. When the brake pedal is down, and the neutral is not properly adjusted, the tractor will try to move forward or backward while cranking, and will make a lot of noise.

I'm betting once you get it started, find neutral with the speed lever, the noise will go away.