1969 580CK - Broken Transmission Gears

[LukeWilson]

Hi everyone, I've been lurking around the forum for some time now but am hoping you guys can help me with my latest problem.

I recently purchased a 1969 580CK diesel with a power shuttle and 4 speed. I bought this machine not running with a broken ring gear on the flywheel. Over the course of a few weekends, I managed to split the tractor and replace the ring gear successfully. This is my first piece of heavy equipment so I learned a lot along the way.

Once the tractor was running I went through the machine and replaced all the fluids and filters, put a couple new tires on the rear, installed new gauges, re-wired the tractor and welded on a roll bar. Everything seemed to be working well with the exception of a couple leaky cylinders.

Last weekend I finally put her to work and started pulling some stumps out which was going very well. As I was using the loader to fill the holes back in, I heard a pop followed by a rattling noise. It was still driving, but I knew something wasn't right. I pulled the shift lever cover off to discover 5-6 teeth broken off what I believe is 1st gear on the countershaft. A lot of the other gears have the edges of the teeth chewed up/rounded, but nothing else is broken. I also noticed that there was a weld repair on one of the shift forks, which is suspicious to me.

Any ideas what might have caused the failure and the rounding of the teeth? I'm planning on splitting the tractor again between the powershuttle and the transmission, but I would really like to know what caused the failure before throwing more money at it.

Here's a couple pics to show what I'm referring to:

The gear that has broken teeth in the bottom of the second picture. It's the first gear towards the engine on the bottom shaft, it is quite a bit more narrow than most of the others.

Thanks in advance for any help or ideas.
-Luke

 

[xgiovannix12]

roundness on the gears is normal shift wear . Chipped teeth would be unproper shifting on the run since they are not syncroed.
sounds like someone was rough on the shifting bending or breaking the forks . I bet the fork for 1st and 2nd were welded

 

[LukeWilson]

Yep, it was the 1-2 shift fork that was welded. I've been searching through the parts diagrams and it would appear that the gear with the broken teeth is actually an oil slinger, not a drive gear. I'm wondering if I can get away with replacing the broken gear and the welded shift fork? It's a fine line between time to do the repair and cost of replace all the parts.

I believe it's number 8 in this diagram:

 

[xgiovannix12]

replacing 8 means you need to work with the ring and pinion. I dont wanna say the broken oil slinger is fine but i think it should be ok. If the gears are not broke id leave them. They should last if the machine is properly shifted. I would replace the forks if they are bent or welded.

 

[xgiovannix12]

after looking at the diagrams the oil slinger is between 3rd and 4th. have you checked every gear in the transmission for missing teeth ? Im not sure if the slinger would cause that rattle

 

[LukeWilson]

Since I heard the initial pop, there is definitely a rattling noise that hasn't gone away in the few minutes I've driven it. I'm assuming this is coming from gear teeth rubbing against each other. Maybe the shift fork bent when the slinger broke causing alignment issues?

Here's the best pic I currently have of the broken gear. The bottom of the picture is the engine half of the tractor.

Thanks for your help!

 

[LukeWilson]

I must have been turned around, you're right, the slinger is between 3rd and 4th gears. I guess it's the 3-4 shift fork that was repaired then.

It's the one with the mechanic's wire on it, hard to see the nasty weld repair in this picture:

 

[xgiovannix12]

that is the oil slinger. Its possible the forks are not engaging the gears correctly

 

[LukeWilson]

I'll have to have a look in the service manual and see if I want to tangle with the ring/pinion. I know it can take some skill to get the engagement pattern set right. Maybe it wouldn't be so bad as I'm not changing the bearings or shims. I would really prefer to replace the slinger gear for piece of mind.

 

[xgiovannix12]

i hear you there. Im not sure how advance your wrenching skills are but anything is fixable. The counter shaft is the pinion so the rear has to come apart to slide the gears off the counter shaft. I think the main has to come apart as well.

 

[LukeWilson]

I'd say I'm about a 7/10 with my wrenching skills, I'll have a better look at it tomorrow when I'm out at the lot. I think my top priority is getting my hands on a 3-4 shift fork and a slinger gear as a start. Alternatively, if someone had a complete transaxle for the right price it might be the fastest way to get back to work. Thanks again for your help.

 

[Tinkerer]

Luke; here is a link to company that sells aftermarket gears and about anything else you may need. I have purchased from then myself. Very knowledgeable people to deal with.
http://www.joseph.com/

 

[fast_st]

Worth running a magnet down around the bottom of the gearbox to see if there are any loose parts, a chipped tooth isn't a big deal but a stray tooth getting between two big strong gears can become something more catastrophic. Sounds like a bent fork could be causing some issues, you might see uneven wear patterns on the fingers. Maybe some new shift forks are in order.

 

[squidrig]

Definitely try to find the piece don't forget to check the drain bucket , might have come out with the oil but usually ends up in a corner crevice

 

[Tinkerer]

Definitely change the oil slinger. It may have more shrapnel ready to break off of it.

 

[LukeWilson]

I'm planning on starting into the job this week. I was able to track down an oil slinger, 1-2 gear, 3-4 gear and both shift forks for a pretty good price.
I have no interest in splitting this tractor a 3rd time, so I figured I'd replace anything with signs of damage/wear.

Has anyone done this before? According to the service manual, I'll have to pull the diff apart.

 

[Grady]

There are a few threads here that deal with this. Do a google search with Heavy Equipment Forum after the subject. Between those threads and the service manual you should be good to go but if you have any specific questions, someone here will surely help out. Good luck.

 

[xgiovannix12]

I'm planning on starting into the job this week. I was able to track down an oil slinger, 1-2 gear, 3-4 gear and both shift forks for a pretty good price.
I have no interest in splitting this tractor a 3rd time, so I figured I'd replace anything with signs of damage/wear.

Has anyone done this before? According to the service manual, I'll have to pull the diff apart.

the Diff has to come apart I dont see any other way of doing it

 

[LukeWilson]

Just about have the tractor split. All of the bolts are out, I just have to pull the halves apart. A hell of a lot easier than splitting the engine from the torque converter!
Finger's crossed I don't find any other carnage while I'm in there.

 

[LukeWilson]

I have found the culprit. Looks like a bolt had been floating around the gearbox and finally decided to jam itself between two gears. Not happy about having to rip everything apart for shoddy workmanship, but glad I found the root cause.

I did find another small pin lying in the front housing. Does anyone recognize it? Looks like its been there a while.

I wasn't able to fully disassemble the gearbox, one of the countersunk slot screws that hold the bearing housing for the diff is seized and I can't get it apart. I'll have to bring the torches out and see if that will persuade it.

I also pulled the shuttle out to inspect/measure the clutch discs while it's apart. I need to put this machine to work and don't want to be repairing it again. More to come on that soon enough.