Trunnion questions into the hydro?
 

I have gotten mixed responses on this. I have the typical problem of the two lower corners being worn. Not having welding capability, I was wondering if there are other options. I see a retaining snap at the opposite end of the shaft, but also see several seals as well as a bearing needle. I'd gladly replace part #SU3103181P (tron shaft) if it doesn't involve additional transmission disassembly, since that would likely also entail seal replacement. I ordered new compression springs and end caps, thinking it'd probably be a good idea to replace them. Thanks...

You have to remove the pump and take it apart to remove the trunnion.
Search trunnion here and see the results.

OK Thanks. That's what I assumed, so the mechanic who is putting together an engine for me must be referring to a different part or else misunderstood what I was talking about. Having never done much work on the trunnion myself, however, I wasn't certain. Out of curiosity, though, I checked on prices for that shaft...around $200. Pretty crazy.

Your lucky today,
My crystal ball that tells me what you are working on,
is slightly clearer than mud.:biggrin2:
So I am assuming you might be working on
a Sunstrand 15 series hydro, if so,
you can replace
3 out of the 4 seals.
Input charge pump,
output shaft,
and the trunion shaft opposite the actuation lever/springs, without taking the hydro apart. :beerchug:

If you have no welding provisions I'd try some good epoxy repair to the worn areas and take a file/die grinder and shape back to fit the spring and guide pins if I'm on the right track with what you are describing , a pic of the area in question may be of some help in trying to give some ideas !:beerchug:

Find yourself a little "Mom and Pop" body shop, take the trans (out of the tractor) to the shop a little before closing time... One of the younger fellows there would be more than happy to weld the corners for you, probably for a six pack of their favorite beverage.

Less than 15 seconds of actual weld time is about all it will take. Take it back home and file the corners square again and you should be good to go.

Yes, as long as you are already there, replace the springs and ends. Keep in mind that the outer spring will not make contact with the ends unless you're actually moving the F/R lever.

Follow instructions in the manual to make your adjustments.

If this is your first one, take your time and adjust it right, it can be a little time consuming but the results will be well worth your efforts.

athomas....I already bought some JB Weld, having gotten advice from others that it might work (although probably a temporary fix from what I hear as well).

Sam...right now the transaxle is separated from the tractor. This was done primarily to replace the cork gasket. Then, of course, I noticed that the trunnion really needs some work as well. So, when you refer to transporting the trans, I assume you mean the entire rear? Or to disassemble further and just take the part of the trans that would be needed to access the shaft? Another issue is that I don't have any sort of trailer or pick-up. Never had any of this stuff apart before either and so somewhat 'flying by the seat of my pants', so-to-speak. Will check the manual for more detail.

Thanks for the helpful suggestions...much appreciated :)

Are you anywhere near Syracuse NY. :bigthink:

If your replacing the cork gasket then the hydro would be seperated from the transaxle and you could take the hydro unit to be welded ! I just clamp a copper bar on the underside ( weld doesn't stick to copper) weld in the corners as needed and grind it back to shape as mentioned before takes a few minutes to make the actual repair ! :beerchug:

Yeah but to do the gasket all I basically did was pull the pump which did not include the tron shaft. Obviously I had to take the cam plate off but the rest of the trans remained attached to the rear axle.

When you "pulled the pump" you removed the hydrostat. Internally, it contains both a motor and a pump, which translates constant speed input shaft rotation to continuously variable output shaft (through the cork gasket) to the rear end.

The trunnion arm is attached to the hydrostat, so it could be carried that way to the welder.

Maybe I'm confused we are talking about this type of unit ? and the cork gasket between the hydro and rear axle ( the one that usually leaks ) ? sorry if I've gone down a wrong path !:bigthink:

Here's what you are dealing with. This is the inside of the hydro with the cylinder block removed. (some other pics show the cylinder blocks and damage from towing this tractor).

The trunnion arm goes out of the picture at bottom left, but you can see how it is attached inside the hydro to the swash plate.

In one of the later pics you can clearly see the trunnion arm and control plate on the hydrostat.

Yeah...now that I look back at pics I took of the cork gasket job, I see that the trunnion arm/shaft was part of what I took off. My bad.

How unreliable my memory is becoming is even scarier than tackling some of these mechanical jobs.
:bash2:

So, now, it's a matter of simply taking the pump back off. No big deal since I still have the cam plate off so we're only talking about 3 bolts. There is a welding shop right down the road. I've had Cub work done there before.

BUT....what about the cork gasket? I already had all 4 of these bolts tight, then loosened 2 of them again when I decided to do some work on the trunnion and hopefully shim up the one plate a bit. Bad for the gasket to loosen / retighten the pump bolts? Guess as long as I wouldn't move the pump horizontally at all and run the risk of the new gasket being somehow damaged - should be ok. I have the JB Weld and was going to try that but...undoubtedly getting it welded is the far better way.

Cub Cadet Hydro Anatomy 101....that helps alot! Thanks for taking the time to post all those pictures.

Cork gasket likely would be ok ,but I wouldn't chance it for a 5 dollar gasket ! don't want to do all the work and have a leak when done !:beerchug:

Anatomy 102..

Not sure what you are implying...so you would...what...get another gasket and take off the one I just put on?

Yea that's what I would do ! like I said if your going to pull the hydro to get the weld repair then I would also put another new gasket in ! Not worth the risk of having it leak if you reuse it !

what is damaged in that pic from towing? just the bullets laying on their sides? time for Sunstrand Hydro 103....
It appears they are spring loaded, looks like they just popped out of place.
I have a hydro from a 129 that would only go forward, did not even have a neutral, let alone reverse. Could this be from moving around without releasing plungers? I have another hydro that I am installing on that tractor so I can get it back operational sooner, I want to dig into it and see what might be wrong within, largely for the experience of it. I have another nice 129 frame without an engine or transmission, if I can fix this hydro I may look for an engine and try to put this other 129 together..... never have had one of these hydro units apart. I have located a couple of seal/ gasket kits via Ebay that don't seem terribly expensive.
(NO, I am NOT gonna send it in for the $1500 "rebuild service" that is advertised there, for one of these units)

there is a guy about 20 miles from me that has all of the innards of a hydro from a 149 listed on Ebay right now. I'm thinking of biting on it for spare parts.

That pin in the swash plate remains inside the shaft, do not try to drive it through, it has to end up centered in the trunnion shaft, take your time or you will be unhappy...

A couple of questions
 

I don't mean to hijack this thread, but I just got done pulling the seat/fender pan of my 149 to get a good look at the condition of the trunion. Like alot of old machines the trunion shows the expected wear in the corners. I have concerns about the trunion shaft and its connection to the pump, my question is how much "play" should there be? Basically left to right the trunion has maybe 1/16" play, is that OK?

I did this over six years ago. It's still working well.


https://www.onlycubcadets.net/forum/...ad.php?t=26356

The slipper feet are crushed/galled and the retainer ring is broken. The feet (the brass things) piled up and cracked the casing. These pistons are not spring loaded, they are hydraulically driven. There is a good article in the tech section on how hydros work. The service manual explains it pretty well, too.

If you are very methodical, and follow the service manual instructions exactly (especially removing the swash plate) and you'll manage. If you put a part in backwards (easy to do)it won't work. So keep everything in exact order.

As long as it's not leaking, a bit of play is fine.
As for the worn spring slot, you can cut off and weld a new rectangle on, spot weld the corners and file back to shape, weld on some strips of key stock, braze some strips of key stock (just need a propane or Mapp torch and a flux coated brazing rod), epoxy some strips of key stock (make sure it's clean).

Replace the springs in the process! As there is really no pressure on the sides of the slots, epoxy gluing some strips of key stock should work fine for many years.