Leaking Final Drive

[sdavies2000]

It’s a good thing his thread exists, I would have definitely taken sand paper to that surface the toric ring sits in.

should the ring sort of twist as it goes in? As in like load up? What I’m reading is you don’t want it to move as it’s installed but if it goes in without a bit of twist or pre load, where does the spring come from?

definitely need new main bearings and races eh. What’s involved installing those? No special tools or heat/cooling required?

i ordered all new needle bearings, thrust plates and pins for the high speed planetary set closest to front cover. Think I should be rebuilding the other two bigger sets?

 

[Nige]

should the ring sort of twist as it goes in? As in like load up? What I’m reading is you don’t want it to move as it’s installed but if it goes in

What you want during installation of each "half" of the seal is for the Toric Ring to "grab" on both ramps and rotate somewhat as the metal ring part of the seal is pressed downwards. The force created by that rotation as the ring is pushed into position is effectively the "spring". Does this make it any clearer.?

In the diagram below the Toric ring #2 is jammed between the ramp #7 and the corresponding ramp in the housing (not shown). When the ring #1 is pressed down the Toric Ring rotates in an anti-clockwise direction and and at the same time compresses slightly, thus becoming "the spring". If the Toric Ring is allowed to slide on one or both of the ramps it will not function as a spring and the seal will most probably leak. The #1 mistake that is made installing Duo-Cone seals is that it's a pretty tight fit to force the Toric Ring past the Lip #8 on both sides. The first thing that folks do is to grab some lubricant to help the process, but if you want the seal to work right after installation that's the last thing anyone should be doing.

 

[sdavies2000]

Yes, that’s makes it pretty clear, really good information there.

Are there some seal groups better than others or are they all pretty much the same quality? I’m told if the box says China, it won’t last and you want seals from India? My box didn’t say anything but a part number and ex200.
This set was half the price of others, 300 vs 600

 

[sdavies2000]

Some light force popping that cracked ring out and...

 

[sdavies2000]

Prepped seal area. It feels so strange leaving that “rough”. Normally rebuilding something, I’d never leave it like that. Is this good? I basically knocked off rust and crap with 2” wheel brush in the dremel. I also knocked out the old bearing races, new bearings on order.
Do I have to install the new races before I can install the new seal?

 

[sdavies2000]

Spindle side seal surface

does anyone have a good way of removing lint stuck to cast surfaces? Considering taking a small propane torch to the fuzzies

 

[sdavies2000]

Pulled apart the high speed planetary set. There’s some grooving in the pins from the thrust plates but the bearings look okay, no blueing.

 

[Nige]

My box didn’t say anything but a part number and ex200. This set was half the price of others, 300 vs 600

Most important, did it have the gauge that is used to set the height of each half of the seal when it is installed.? If not hopefully someone with Hitachi experience will be able to tell you what the measurement is. It's important to maintain the specified height measurement +/- not much all the way round the circumference of the ring.

 

[sdavies2000]

Rebuilt planetary set... anyone see a problem?
I love doing things twice

Nige, there was nothing in the box
What height are you referring to? I took a measurement of one height when disassembling...

 

[Nige]

Nige, there was nothing in the box
What height are you referring to? I took a measurement of one height when disassembling...

Back in the day every new seal group had a small plastic height gauge in the box to assist the installer in ensuring that the seal was not installed "cocked" after it was in position. The Rollos Royce solution is to use a dial indicator. All these instructions refer to Cat seals. While to a great extent Duo Cone seals are similar I would not simply assume that the height measurement quoted in the attachment is correct for your particular seal group.

 

[John C.]

I haven't seen that for years now. Don't think I ever saw that on the Japanese machines.

 

[Nige]

8T0537 was the Part Number for the plastic height gauge. I see that Cat have discontinued it but it's still available aftermarket apparently.

 

[sdavies2000]

Is it best to install the bearing races into the sprocket side prior to installing the one half of the duo cone seal in its housing? I’m worried that if I successfully get the seal installed, I’ll damage it or it will get mispositioned somehow when I’m flipping the sprocket around and pounding the races home on each side. The spindle side should be okay to install the seal on first.

 

[John C.]

I usually install the seals after everything is in place inside and the I put the seals in and mate the elements together.

 

[92U 3406]

I always do seals last.

 

[sdavies2000]

Okay, bearings should be here next week, project on hold until then.

 

[sdavies2000]

This project took a back seat for a while, I apologize for anyone that was following along.

I got back at it today, installing the new races and Bearing on the spindle.

I then moved on to the cone seal using instructions from Willy posted earlier in this thread. I found some wire that fit the gap nicely and had everything clean. Without using any lubricant or alcohol, the seals went in fine using just my thumbs to gently push the toric past the lip. This worries me since I was expecting this to give me a hard time. I imagine the further you push the toric/seal down into the housing, the harder it would be. I don’t know how far I’m supposed to push it down into the housing. The further you press it, the bigger the gap it creates between the toric and the housing lip which I thought was preferred to be zero.
Currently, the top of the toric sits proud of the housing which I’m not sure is correct. On the sprocket side, the actual seal is sitting much higher than the old one. I took a picture of the old one before I took it out with a flat edge and a ruler to see height.

I don’t want to put these two halves back together before I know this is right. The seal has good “spring” to it right now when pushed down

 

[sdavies2000]

Old seal

 

[sdavies2000]

New seal sitting much higher

 

[sdavies2000]

I was going to upload video of the “spring” but not sure how to.