580C Transaxle- whats on my gears?

[melben]

Delmer,
Actually, this started out as a brake job and leaky seal repair. I do take care of my stuff, but I run my tools and equipment pretty hard. If I was not going to keep it I would probably just call it a day. Between keeping it and being a little OCD I'm going to fix it. The thought of diving into my dirt piles with that much slop makes me nervous. It will be a bigger and more costly job later. Plus I enjoy learning and doing the work. Knowing what I know now I would have bought a newer lower hour machine for more money.

Stinky64- I'm just going to put things back to specification and replace the seals. Replace the thrust washers if they are damaged. Bearings and gears look great.

Steve

Dirt, the thrust washers at the side gears were originally made of a fibre or bakelite looking stuff but all were subbed to hardened steel washers and are selective thickness to set the spider to side gear clearance. A factory manual would be your friend on this job, The resulting increase in the ring and pinion mesh accounts for many ring and pinion failures from improper tooth loading. To properly set the ring and pinion you should have a dial indicator, I have a magnetic base I use, I always set up on the tight side of spec. another thing and I will accept all the beatings anyone is passing out for but I always set the shafts up with slight preload even if it calls for a bit of end float in the manual. I have done hundreds of them and I have never seen one wear tighter and never had a bearing or race failure with preload. Install your brake seals before the final assembly after the shimming is done and be very careful not to roll the brake shaft seals, also do not forget to replace the small seal where the differential shaft comes out, a lot of RH side gear seals have been replaced when the small diff lock seal is the culprit. Ok I'm ready for my beating now about the preload!!

 

[melben]

Dirt, the thrust washers at the side gears were originally made of a fibre or bakelite looking stuff but all were subbed to hardened steel washers and are selective thickness to set the spider to side gear clearance. A factory manual would be your friend on this job, The resulting increase in the ring and pinion mesh accounts for many ring and pinion failures from improper tooth loading. To properly set the ring and pinion you should have a dial indicator, I have a magnetic base I use, I always set up on the tight side of spec. another thing and I will accept all the beatings anyone is passing out for but I always set the shafts up with slight preload even if it calls for a bit of end float in the manual. I have done hundreds of them and I have never seen one wear tighter and never had a bearing or race failure with preload. Install your brake seals before the final assembly after the shimming is done and be very careful not to roll the brake shaft seals, also do not forget to replace the small seal where the differential shaft comes out, a lot of RH side gear seals have been replaced when the small diff lock seal is the culprit. Wiht everything in place and cleaned up I always put one side brake on and tighten it up, that holds the brake shafts on center while you are installing the brake plate on the opposite side, that may sound like a little extra work but it is a rel time and seal saver in the long run. Ok I'm ready for my beating now about the preload!!

 

[melben]

Sorry about the screw up, I added info and done something wrong, Oh Well!!

 

[stinky64]

Steve,when you look up the thrust washers in your parts manual you'll see 6 different sizes, when I ordered mine the sizes ran 1 size smaller,all cnh dealer parts..thought my mic. was off so I borrowed another quality mic. from a guy at work and confirmed smaller size...when I ordered 3rd washer, ordered 1 size bigger and it worked, just throwing that out there because I hate being stopped dead in my tracks because of wrong parts.. probably applies across the board..good luck with the build...Stinky, Almost forgot when you put the carriers back onto the side gears, follow Tinkerers advice and use clear packing tape and a lot of lube so you don't roll or tear the new seals on the splines..thanks Tinkerer, worked for me too

 

[Delmer]

The preload is no different than any other roller bearing, right? The ideal is a little preload, but it will die faster with a little too much preload, than a bigger amount of slop, so they recommend the slop. I mean, free play, not slop.

 

[DirtyHoe]

Thank you everyone for all the excellent tips and ideas.
Melben- Out of curiosity when you tore these down for repairs was it common to see a lot of end play on the rear axle shafts, pinion shaft, and main shaft? Do the bearings and races loose size and contribute to this extra clearance from normal wear and tear?

Stinky64- It's hard to get everything lined out for a bigger job. I'm either missing a part, don't have the right tool, or damage a small special order o-ring. I've been ordering from Dale at e-backhoeparts.com too. My other favorite place is McMaster-Carr for hardware.

I hope to work on it this weekend and figure out what new parts I will need.

Steve

 

[melben]

Thank you everyone for all the excellent tips and ideas.
Melben- Out of curiosity when you tore these down for repairs was it common to see a lot of end play on the rear axle shafts, pinion shaft, and main shaft? Do the bearings and races loose size and contribute to this extra clearance from normal wear and tear?

Stinky64- It's hard to get everything lined out for a bigger job. I'm either missing a part, don't have the right tool, or damage a small special order o-ring. I've been ordering from Dale at e-backhoeparts.com too. My other favorite place is McMaster-Carr for hardware.

I hope to work on it this weekend and figure out what new parts I will need.

Steve

I have not experienced a lot of issues with axle bearings over the years, when you tighten them up tighten them tight, they are a slow rolling shaft and will not overheat. I would imagine bearings or races can wear but that is not the norm. As previously stated by others, deterioration of the LH side gear thrust washers is the main cause of ring and pinion failures. Counter shaft loosening up was hardly ever a problem. Set everything with a rolling torque as we discussed earlier. BTW, the spacer behind the bearing on the counter shaft is selective also and it is to be sized so that there is a noticeable spacing between the gears that are stacked on that shaft when rolling torque is proper. If that spacer is to thick the gears will "stack up" and rolling torque will not be able to be set, gear clearance can just be a few thousandths but must be there.

 

[stinky64]

I think more often than not the damage to bearings/races is due to the milkskake of doom in the transaxle from previous owners neglect...I changed mine out because they were badly pitted from moisture/water in the housing...

 

[DirtyHoe]

Worked on the disassembly a little tonight. The picture below is a good argument for having very little clearance or some preload on the bearings. Both rear axles had end play which got worse over the years. The bearing cone ate into the bull gear.

The gear looks symmetrical about the splined hub. Any reason that I can't machine the damaged area flat, then flip the gear around so I don't change the side to side alignment of the gear to the side gear it meshes with? By flipping it around the castle nut will take up the extra space I machine off.

I was hoping to not have to remove the transaxle because I'm not really set up for handing big heavy stuff. But the welded in steel tubing cross member is in the way of lifting the big bull gear out. It's always something. I did get both axles out. At some point in the tractor's life, it received a lot of love(grease). Each axle housing has at least 2 tubes of grease laying in the belly. No water or oil in the cavity, so the seals were doing their job.

Any guess as to what the transaxle weights? The axle alone was almost too heavy to carry by myself.

Steve

 

[stinky64]

Steve, one of my gears was worn the same way, I ran a weld bead around it and ground it as flat as possible, ran damn near true when installed, no visible wobble...don't know what the weather is like in your neck of the woods, but if you have the tires removed set the housing down on 6x6 blocking, 2 under each axle housing and enough to support front of housing and you can move the machine up and over the housing with the hoe..It seems a lot harder than it actually is..4 bolts either side,disconnect brake lines, remove driveshaft,remove two front support brackets on transaxle, and there's a clamp on the right side hydraulic line that needs to come off so you can get to one of the housing bolts..I know I'm forgetting something but it's not really that hard,really nice to have a helper with another set of eyes outside of machine...One really important tip is to block the front axle so the rest of the machine doesn't pivot when going up and over the transaxle because the stabilizers won' be of any help at this point..I wouldn't recommend trying to move housing by yourself,If you have a neighbor with a tractor with a loader a box of beer will probably get them interested in the job...

 

[Delmer]

I assume those bores are supposed to look like that because they're heat treated, right? Can somebody confirm they all have the heat color? not the wear you're talking about.

 

[Tinkerer]

It appears to me there was some serious friction on it.
Quite a bit of metal is gone by the looks of all the hangies.

 

[stinky64]

Both of mine were blue around center spline, only 1 was worn like that and the cotter pin in that side had been replaced (poorly), maybe someone replaced a seal at some time and torqued poorly as well,,,,

 

[DirtyHoe]

Does anyone have a guess as to the weight of the transaxle? I'm not sure if my Kubota L3560 tractor with forks will pick it up. It's rated at about 1,700 pound lift capacity.
I have everything disconnected and the mounting bolts loose. Blocked and ready to remove.

 

[DirtyHoe]

Steve, one of my gears was worn the same way, I ran a weld bead around it and ground it as flat as possible, ran damn near true when installed, no visible wobble...don't know what the weather is like in your neck of the woods, but if you have the tires removed set the housing down on 6x6 blocking, 2 under each axle housing and enough to support front of housing and you can move the machine up and over the housing with the hoe..It seems a lot harder than it actually is..4 bolts either side,disconnect brake lines, remove driveshaft,remove two front support brackets on transaxle, and there's a clamp on the right side hydraulic line that needs to come off so you can get to one of the housing bolts..I know I'm forgetting something but it's not really that hard,really nice to have a helper with another set of eyes outside of machine...One really important tip is to block the front axle so the rest of the machine doesn't pivot when going up and over the transaxle because the stabilizers won' be of any help at this point..I wouldn't recommend trying to move housing by yourself,If you have a neighbor with a tractor with a loader a box of beer will probably get them interested in the job...

I'm thinking about doing a TIG pad weld instead of MIG. Are the gears cast steel and easy to weld?
I can't weld as accurately as I did in my 20's. I would like to stay out of the splines and avoid the hassle of grinding and filing my mistakes off. Bifocals help, but I wish I had my younger eyes...

FYI- I did find in the manual that it says the bull gears are stamped "Nut Side". So I can't flip it around like I wanted to in my earlier post.

Steve

 

[stinky64]

Your kubota should be more than enough to move the transaxle anywhere you want it..As far as welding, I used an old Lincoln red box with 7018 rod so a decent mig or tig should work just fine,if you accidentally get into the splines use a flat file to clean up and prefit gear before putting back in the machine... I thought about flipping the gear around myself, but the inside collar is just a bit larger..That whole new eyes thing is just a dollar store and $6.00 away,I've got a pair of 2.50's just for welding and reading on the crapper

 

[stinky64]

Steve when starting removal make sure to take bolts right out, you have to move machine forward a bit to clear the two studs on the front of the housing that go through the crossmember before you go up,,I knew I forgot something...

 

[DirtyHoe]

Well, this ruined my day.
I found out the cause of the shaft end play. The countershaft(pinion) blew out the snap ring and a chunk of the casting to the inside of the transaxle. The bearing cup had excessive force on it for some reason. Has anyone seen this failure on a 580C? Not sure if this can be re-welded and re-machined? Or maybe bore the hole oversize and press in a stepped bushing along with a shoulder to replace the snap ring? Unfortunately, I don't have a horizontal mill to tackle this myself.

This may explain why everything is loose and not assembled correctly. I'm guessing a previous owner found this problem and decided to slap it back together and sell it.

I have found no further damage besides the bull gears. All the bearings, gears, etc. seem to be in great shape. I would love some advice on how to move forward.

Steve

 

[edgephoto]

You can probably have it bored oversize, a bushing made and fitted so the stock bearing will fit. It won't be cheap but better than throwing away the machine or trying to find a used part.

 

[stinky64]

That truly sucks, looks like someone over torqued those bearings and blew the snap ring out of the case...there's not that kind of pressure on that cup/ring for the machine to do that...I'm not much for ghetto repairs, but it looks like you have enough of the snap ring groove ..that if you order a new snap ring set it into the groove and mig that top radius you may be able to save it..I would order a new pinch nut as well so you can feel the real torque you're putting the bearing,without the previous crimps in the old nut,no real pressure on that nut that's all you have to do is remove/set endplay...just a suggestion..what do you have to lose? If it doesn't work then you can pursue the boring/bushing method...Not even my machine and it ruined my day...