D9h bevel gear shaft.

[gary808]

Hello everyone,
So we're working on a d9h that had a steering clutch non release issue. What had happened was the outer hub walked loose and the nut and the lock bold ended up in the basket. When the clutch was applied it caused the clutch to smash and jam.
The last owner pulled the outer shaft and fixed and pressed a new hub on. They changed the piston seals but didn't do the swivel seals behind the hub.

When we got to the machine we tested it and found the swive seals were gone. We also checked runout on the inner hub and found 10 thousandths run out on it.
We pressed the hub off and found what looked like the front half of the taper belled.( looked looseand worn)
The hub has been making metal to metal contact where the seals run with the bearing housong.
We did out best to check run out on the shaft itself using a feeler guage against the threads and a dial indicator and got 6 to 7 thousandths run out.

Does anyone know the max permissible run out on the shat?
We're looking into either replacing the hub and bearing housing or changing out the bevel shaft.

 

[Old Magnet]

Seems your issue is with a compromised spline/taper on the bevel gear shaft. I'd expect run out to be only a couple of thousands but I couldn't find any specs. My parts diagram is for the D9G but I believe the "H" is the same. If the replacement hub has been running that much out of round it probably has damaged the seal surfaces as well.

 

[gary808]

Thanks for the info. We haven't tried a new hub on it yet. We're hoping the old hub just belled out on the taper spline.
We're going to be pulling the shaft this week. We didn't plan on it but during the process of running it to dial the shaft the bearings sounded terrible. We measured 11 thousands play up and down.
We figure pull it and replace the bearings and we can check the shaft in a lathe.

It's really frustrating caterpillar didn't machine a a smooth spot after the threads to check runout. It's hard to guage off the threads.

 

[Old Magnet]

Specs on the hub press is 35-40 ton and the distance between the face of the hub and the shoulder of the bevel gear shaft should be 0.12", +/- 0.03 in. Might consider a little less press tonnage if belling or splitting the hub is a concern. Good plan on checking the shaft in a lathe. If tapered splines are buggered up or the hub presses to far it's a no go.

Be aware that early machines have piston that is free to rotate. Later machines have the piston and pilot splined together and rotate as a unit with the hub.

There should be an unthreaded portion of the shaft before the shoulder that could be used to check run out.

 

[gary808]

The specs you gave on pressing it on look like the same specs in my h book. They do have a little note saying later model h's will have higher tonnage I think it said 50 to 55, same distance.

This one took about 60 tons with heat to get off. When I put the torch on the hub I did notice oil bubbling out of the front of the hub between the splines.
We will make sure to press it on slowly and periodically check it.

We might have to switch to a older hub and piston if we can't locate a h one. There are plenty of gs parted out locally.
I double checked the shaft and couldn't find a spot to run the dial indicator on. Cat ran that thread right into the face of the spline.
Thanks for the input it's greatly appreciated.

 

[gary808]

Mind the horrible oil. This is the press unit we built.

 

[DMiller]

Looks to have a little moisture in there.

 

[Old Magnet]

Typical tropical climate, can't keep water/moisture out of anything.

 

[gary808]

The oil is horrible, probably the worst oil I have seen in a while. Watery plus they were running that brake with no steering clutch. Its full of brake meterial. Plus they changed the seals on the outer hub shaft that goes into the final drive and managed to put one of the seals in backwards so it was leaking oils back ans forth.

I'm hoping the water is from the brake covers being glued on with rtv red and absolutely no effort to clean the surfaces. They didn't even tighten all the bolts.
It's hawaii and it rains alot, either thay or a bad trans cooler.

 

[gary808]

Here's some pics of the tear down. Spent a few hours pulling the right steering clutch and removing the bevel gear cover.
We also drained the old oil.
We managed to get a used good shape bevel gear shaft, hub and bearing housing for the left side.
The bevel gear and pinion had 55 thousandths play in it.

 

[Old Magnet]

Was wondering how it was going, looks like your in to it. Good luck with repairs.

 

[gary808]

Was wondering how it was going, looks like your in to it. Good luck with repairs.

We're really into it now. We got the shaft out and in the lathe. It has a ten thousandth bend on one end of the shaft. We also found the right bearing housing seal groove is torn up.
We're trying to locate a replacement. If we can't we will machine it out ans press in a hardened sleeve.
We also noticed a questionable line on one of the teeth on the pinion.

We got a new used shaft, we checked it in the lathe ans it runs true.
We also got a used good hub and bearing housing for the left side.

 

[Old Magnet]

By questionable line does it look like a pending fracture? Can't really tell from the picture. That 0.055" backlash probably didn't help any. What kind of service was this tractor in, seems it lived a hard life.

 

[gary808]

It looks like either metal flakes smeared over or a possible fracture starting. We're going to clean it well and get a better look at it.
Worst case we will be pulling the trans to change it out for a new pinion before we re shim the bevel gear shaft.
The story on this unit is murky. It was at one time working in California then sold and shipped to hawaii to rip and pack lots. The lack of service was on this end of its life and happened in a period of a year or two.
We purchased the machine broken hoping the damage wasn't to bad. But as of now it's looking like we're in for our money's worth.
We can make back the investment pretty fast leveling lots. Most lots are 1 acre. It's about 12 to 15k to rip up the lava rock and level it. Rocks not that hard but if your abusive it will destroy a d9 in a shot period.

 

[Old Magnet]

Forgot to ask, what is the s/n?

 

[gary808]

We still haven't found a serial number for this tractor. It seems all the tags have been removed. We have just been going off part numbers ro replace parts.
The machine seems to be a latter serial number machine. Most of the parts are later revised parts numbers.

We end up locating a brand new replacement bearing housing for the right side for $250.00 +100 shipping.
We are now just waiting on bearings to show up.
We still have to make sure we don't have a failing tooth on our pinion. I really wish cat made it so you could remove the pinion from the back of the trans.

 

[Old Magnet]

s/n should be stamped on the rear case where the tag is normally found.....unless it is covered up by the ripper attachment.

Lots of room to work in there with the trans out....

 

[gary808]

Nice pic, is that you in the pic?
We're gonna order a new pinion tomorrow along with new pinion bearings.
We're 90 percent sure its a crack or the start of a fracture on the pinion.
I'll try to take some pics of the trans on the way out.
My only fear is what else we will find failing when we open the trans up.

 

[gary808]

And at the moment the ripper is on the rear of the tractor. We're planing on pulling it after we get the machine up and running. It has a loose nut, possibly a broken stud.

 

[Old Magnet]

That's a buddy working the "flintstone" tractor LOL. I was taking the picture.

Good call on the pinion, you don't want to be going in there again real soon.