Replacing seals on trunnion shaft.

[ol'George]

Originally Posted by J-Mech

You can get the seals at NAPA. They're like $7.50. SKF 6763

$4.73 from Deere AM3426T

[Terry C]

Probably a combination of Id andOd too close and that it doesn't spin completely
around. Much like a ball bearing will wear itself out if it doesn't rotate far enough
needle bearings dont need to turn as far

[yeeter]

I just did a set of hydro seals this weekend. Out of the tractor, it is a half a beer job. If you have to pull the rear, from scratch, it is a three beer job

You decide which is preferred...

[Alvy]

Originally Posted by J-Mech

Also, I have yet to have a LH trunion seal leak. Guys talk about leaking trunion seals on here pretty often, and they too have a RH one leaking. It's always the right side. Someday, I'm going so sit on a bucked and think about it and figure out why that is.....

What about the possibility of the trunion shaft having more leverage on the right side as the movement is controlled from the left side so the right would have more force and more wear on it's area than the left?

[J-Mech]

Originally Posted by Alvy

What about the possibility of the trunion shaft having more leverage on the right side as the movement is controlled from the left side so the right would have more force and more wear on it's area than the left?

Should be just the opposite. Since it is controlled from the left, that shaft has switching side/directional load. The other (RH) side only has the pressure from the pump on it. By all theory, it should be the other way around. I would have thought the LH side would be the one to always leak.

[ol'George]

Originally Posted by J-Mech

Should be just the opposite. Since it is cont ) side only has the pressure from the pump on it. By all theory, it should be the other way around. I would have thought the LH side would be the one to always leak.

I thought my theory made sense, but it is just that, a theory.
2 pins in the trunion allow no cocking of the L shaft in the seal, 1 pin allows the R shaft to cock/wobble around as it is a slip fit in the trunion, Granted it is a minute amount.
Wonder if putting 2 pins in the right side would give equal seal life?

[yeeter]

Would one side run warmer than the other? Sometimes age/heat hardening of the elastomer is more important than load

[J-Mech]

Originally Posted by ol'George

I thought my theory made sense, but it is just that, a theory.
2 pins in the trunion allow no cocking of the L shaft in the seal, 1 pin allows the R shaft to cock/wobble around as it is a slip fit in the trunion, Granted it is a minute amount.
Wonder if putting 2 pins in the right side would give equal seal life?

I just had one apart the other day. Only one pin in both sides. Parts book only shows one pin in both......

Originally Posted by yeeter

Would one side run warmer than the other? Sometimes age/heat hardening of the elastomer is more important than load

Nope. Same.
All I've ever had to change the seal wasn't hard. By all theory, that trans shouldn't ever be able to run hot enough to cook a seal. That would be over 200°.


My best guess is that the LH side is more protected having all that linkage in front of it. I would also be willing to bet that if I would disassemble the hydro and change the bearing it would stop the issue..... but that's just a guess.

[ol'George]

Originally Posted by J-Mech

I just had one apart the other day. Only one pin in both sides. Parts book only shows one pin in both......




Nope. Same.
All I've ever had to change the seal wasn't hard. By all theory, that trans shouldn't ever be able to run hot enough to cook a seal. That would be over 200°.


My best guess is that the LH side is more protected having all that linkage in front of it. I would also be willing to bet that if I would disassemble the hydro and change the bearing it would stop the issue..... but that's just a guess.

Jonathan,
I find that interesting, as you say only 1 pin shown per shaft in the parts look up on parts tree, and the same thing in the service manuals listed here on our site for both the QL and the 82 series,-- but also, they say
" note: there are two pins used in the control side". and go on to describe how to drive them out carefully, not too far.
I can tell you I removed 2 pins from the control side a couple of days ago on the 1650 hydro and re installed 2 pins on that side and one pin on the other side.
Confusing to say the least!
Bottom line I would say better two than one since they specifically make mention of two even though they omitted one in the diagram.

Interesting also, while looking up parts for the hydro on JDparts they showed both pins on the control shaft, so it goes, always muddy waters somewhere.
FWIW:
Somebody is gonna ask why I go to my local green dealer for parts,--- because I have an account there, there don't charge shipping on stock orders, they get me most anything I need, and besides competitively priced, they are 5 miles up the road, works for me.

[J-Mech]

I've had a few of these hydro's apart. Some have had 2 some one. Who knows why some are that way. Two would make sense, but when I was putting that one the other day back together I didn't give it any thought, nor did I have another pin, so it got one. Two is not a bad thing. I think the shaft fits the swashplate tight enough that I don't really think that putting two in the far side would matter, but who knows. Next time you do one, give it a shot and let us know in 5 or 6 or 10 years if it leaks, LOL.


As far as getting parts at Deere, I don't think anyone here said anything about it. Same parts, different bag, different price. I'm fine with it.