877 case leak

[Martin 2,133]

if you say there is no play in it, i think you would be good to go......

just went back and looked at my thread on the situation. i think i remember mine being a little off center as well. not 100% on that though. that large o ring is a pain to get centered in the shim i.d. and keep it there while assembling the cam plate support to the pump....

make sure to get the smaller/ thicker one on the shaft first before installing the cam plate support and then install the support with the shim and large o ring positioned correctly on it with bolts to hold the shim in place (just like in the first pic below)......

make sure the small diameter o ring fits into the recessed area in the support.. a very small amount of atf on that one will help you slide it home......

 

 

Edited March 9, 2013 by Martin

[csvt99 173]

Thank you Martin. I got it all back together but unfortunately it is still leaking. When I tightened up the allen screws, I tried not to overtighten them. I stopped tightening when everything fit together snuggly with no gaps or spaces in between. I've attached some pics of what it looks like. How do you know when the large o-ring is in the correct position?

 

The one picture shows the fluid coming out into the cam block. It's really hard to see, and I had to take a pic of the reflection in a mirror in order to see it, so I outlined it in red.  

 

 

[Callen 64]

Try tightening it up more. The metal gasket (shim) provides the proper squish for the o-rings. If that doesn't work, you'll have to pull it apart again and get a fatter o-ring for the shaft.

[Martin 2,133]

i wouldnt tighten it too much. the recommended torque is six lbs.

the thickness of the large diameter o ring should compress just enough when the support/shim is snug to the pump. i would check to make sure the smaller diameter o ring is thick enough and is indeed sealing. the support was hard for me to push up snug BEFORE tightening the screws......

some of these o ring dimensions that are used are hard to match up in standard sizes.

 

there was a bulletin issued on this as well, not sure if it was mentioned in the past......

 

ServiceBulletin_WH61-90_067_650728_Wheel-a-matic_Tractors.pdf

 

you didn't mention where you got the o rings from. was the large one a toro part? i couldnt find anything that was even remotely close to that anywhere else. i think the smaller diameter one i used was just slightly thicker than what was removed from the tractor. im fairly sure that nobody had every been in there before so im confident it had the original o rings in it.....

Edited March 10, 2013 by Martin

[csvt99 173]

For some reason I wasn't able to open that Bulletin. When I clicked on it, it tried to go but never did. Even had my pop up blocker off.

 

Anyway, I got the larger O-ring from Toro via the wheel horse part number. The smaller one was no longer available so I found one to match the one I pulled off the tractor. I even used a caliper to make sure I got the thickness just right. I believe it was 3/32 if I remember correctly. After talking to my dad again the only thing we can come up with is that the one we pulled off the tractor was too small to begin with, and therefor the one we replaced it with was too small as well. How do I know the correct thickness of the correct o-ring? Would I be able to get a spec on that smaller o-ring even though it's not avaliable from Toro anymore? I'm not pulling that thing apart again until I know I have something that will work

[Martin 2,133]

i really have no way of checking for you, other than pulling one down to measure it. i have a spare hydro but its not leaking so dont want to open a can of worms there. i wish i had documented mine more when i did it. maybe some careful searching or googling might help. sometimes i buy double what i need of this oddball stuff, but i just checked and dont have anything i could measure.....

[csvt99 173]

No problem Martin; I do appreciate the effort. I'll check with my dad's buddy who has the Toro dealership and is a long time WH nut. Hopefully he can help me out. I guess I can always try to get one that is a little thicker and see what happens. It did go over the shaft pretty easily; I had to work it a bit (maybe for 2 or 3 seconds) but it went right over. Didn't need a drop of oil or anything.

[Martin 2,133]

when installing the cam block support the recess the smaller o ring sits in was 'firm' to get over the o ring. i didnt have to force it, but it did need some slight pressure with the oil as a lubricant to slide the support home.....

its like the recess held it against the shaft and compressed it against the pump at the same time. if the o ring is slightly smaller it could give it too much room in the recess and not provide the right amount of crush. admittedly even with measuring an old one, its still going to be slightly smaller than a fresh o ring.

i would try and get some similar size smaller ones and test fit them first with the shim only and see how they feel before installing the larger o ring. 

i would always recommend a little wipe of oil on them as well....(whatever they are going to be exposed to in service)

[csvt99 173]

I was finally able to download the service bulletin. Very interesting, I'm extremely greatful to have this as a resource. I guess I'll have to borrow a torque wrench when I put it back together to make sure I get the 6 lbs. They bulldozed the NAPA near my house so I went to the ACE store today to look for O-rings. They didn't have any matches in the lawn shop so I pulled one from plumbing. Will one of these o rings from the plumbing department be okay in the transmission? I asked they guy there and he said they are made from the same material. Check out the photo and let me know if you think it will work. Thanks!

[Martin 2,133]

hard to tell from the pic, im trying to compare it with my pic above of the smaller diameter one on the shaft for thickness. definitely looks closer than the one on the right from your transmission. i would test it and see how it feels. its really hard for me to say whether its the right size or not as i dont remember the dimensions of the one i removed from mine.

i would say if it installs without having to force the support over it, (make sure you lube the o ring), and the shaft will move through reverse and forward without much effort, you may be ok.

 

from comparing the one on the right of your pic with mine in the pic above, i think you were too thin on the one you installed, hence the leaking. 

[Martin 2,133]

heres a chart of sizes. maybe of some help. unless somebody can come forward with a definite size then you just need to experiment a little. i found my local ace to be limited in sizes close to what i wanted, the napa had a size under and over what i thought would be right, i remember buying two or three different sizes but who knows where i put the left overs......

 

http://www.allorings.com/size_cross_reference.htm

[csvt99 173]

I might try replacing it this afternoon. I don't have a little torque wrench so I'm going to try having my wife pick one up at sears since she is already there. Does anyone know if I can replace the O-ring without splitting the tractor like the bulletin shows? I'm guessing I'll have to split it in order to remove the cam block, as that wasn't necessary for the work described in the bulletin.

[Callen 64]

Pretty sure you will need the room to drive the pin out.

[csvt99 173]

The new, larger o-ring will be a very tight fit. Honestly it seems too large but there are no sizes in between. It is very difficult to get it to fit into the seat on the cam block without deforming, and the only way for it to fit over the shaft is when it is loose. I'm going to try a couple things yet before I bombard everyone with a ton of pictures and questions. In the meantime I had a bit of a set back. I had the tranny propped up in my garage and some how it tipped over and all the fluid ran out. Since the tractor was in an abandoned, mouse infested chicken house/ barn for the past 20 years it is filthy so I'm going to take my time cleaning it and putting it back together.

[sorekiwi 761]

I dont know if you read any of the thread at MTF that I linked to earlier.  But that guy had some issues with getting the O rings to seal.  It might be worth a read.

[csvt99 173]

I actually did read that post before but it makes a lot more sense now that I've gone through the process. It could be that I didn't have the screws tight enough. I have a little torque wrench now so that won't be an issue this time. When I took it apart the second time the larger o-ring looked fine, and that isn't where the leak was coming from anyway. I'm going to try putting it back together with the thicker o-ring. Hopefully it will go in the seat when I slowly torque the hex bolts. If not I guess I go back to the smaller thinner o-ring and tighten down to 6 lbs and hope that does it. I guess there is no way to test this thing for leaks without hooking it back up to the belt and running it....

[csvt99 173]

Knock on wood, all is good. The new, larger o-ring must have worked it's way into the seat of the cam block as everything closed up nicely when I torqued it down with a 3/8 drive torque wrench to 6 lbs. I ran it up on the stands for a while and so far I have not seen signs of it leaking.

 

Thank you for all of your help. I'm still not 100% convinced I'm in the clear, but I'm hoping it gets me through the summer into next winter before I have to do any major motor/ transmission work.

[csvt99 173]

For documentation purposes:

 

Problem: Transmission fluid was leaking from tractor. It seemed to be fine during operation, but once I was finished using a small pool would show up under the tractor. Enough to require putting newspaper underneath.

 

Source of Leak: When I investigated, I found the leak to be coming from the INSIDE (or engine side) of the cam block. The suspected culprit was o-ring # 52 (shown on page 54 of the hydro manual, part number 972116).

 

Fix:

 

The larger o-ring (PN # 970026) was available from Toro dealer. I replaced this with no problems.

The smaller o-ring (PN # 972116) was NOT available from Toro dealer. I ended up using a 1 X 3/4 x 1/8 # 15 O-Ring, which was 1/32 thicker than the "bad one" I pulled off the tractor. During my test run I did not have any leaks. Hopefully this holds true after I get it back on the ground. If I have more problems I will re-visit and update this post.