RCK60P - 28Z gearbox

[davemskinner]

Can anyone tell me if the gearbox for a ZD28 mower deck is the same as for a ZD28F? I have the gearbox apart that came on the above deck. It appears to be different from the parts diagram.

I have spent $600 on parts and they don't fit. It appears the box is too small for the pinion shaft and gears. My only thought is that the gearbox was swapped onto this deck from another model. In the second picture, the two boltheads on the front facing side are not in the parts diagram. The fourht picture shows how the baering will not seat deep enough to put the sanp ring in. The last picture shows the pinion gear on the pinion shaft. There is a shoulder separating the shaft into to sections and the gear only slides on the splines as far as they are ground down to allow. The gear does not seat all the way up to the shoulder.

 

[davemskinner]

OK, so how do the new parts look compared to the old parts? The gear case, pinion shaft and everything else on that gear box is used on every single mower deck, so something is really wacked out!

It is possible to get parts that are packaged/boxed wrong........been there, fought through it, over came the denial!

Lets see some pictures of these new parts up against the old parts and a listing of all the part numbers you've been using in this rebuild.

We'll find an answer!

View attachment 4028

You da Man Vic!!!

I'll get all of that up here tonight.

When I bought the tractor (mower), the guy had just "rebuilt" the gearbox. It came apart shortly after I got it and I thought that the bolt, that holds the pinion shaft had just come loose. So, I put it back together, the way it came apart, without really checking everything over... stupid me. What I mean by "came apart" is the belt started popping off and then I found loose pulleys and broken seals.

When it came apart this time I really started looking and found bad bearings, bad gears, the pinion shaft was bent, and the main shaft and pulley were worn out (where the feather key goes). I also noticed that the pinion shaft was not fully engaging the end bearing where the bolt goes.

What I realized was that the bearing on the other end was on the inside of the collar which made the shaft too short. Or so I thought anyway. So, I ordered all my parts and went to install everything and am finding the shaft to appear to be too long with the bearing on the outside of the collar, like the parts diagram indicates. Just for giggles, I tried the new bearing in the new shaft, on the inside of the collar and it won't slide over the shaft. It fits beautifully over the outside portion of the shaft.

Obviously the bearings need to be seated inside the snap rings. I notice there appear to be two grooves. One on the very outside of the opening and one deeper in. However, if one were to attempt to use the outermost groove for the snap ring, there would not be enough room for the seal.

As far as the parts go, the new ones are the same as the old ones. This is what led to my question because I wondered if they substituted a different box and I was buying parts for an original gearbox when I needed them for some other box. Based on what you are saying, I am not as handy as I thought and must be doing something wrong.

Thanks again for the response Vic. I'll post all detail tonight - off to work now!

 

[davemskinner]

Vic, I have included the parts lists that I ordered from. I did not order anything from the first group. The parts I ordered in the second group are all bolded. I have been trying to get the parts layout pictures to upload but I cannot get them shrunk down enough to upload. The one you supplied, looks identical however, I noticed the yours specifically indicates a ZD28F. The parts breakdowns came from Messicks. My serial number is 31236. I included the first group only so you could be sure of the part number for the case.

Messicks tells me there is a serial number break for the deck but it is not affecting the parts I ordered. At least according to the parts list.

The parts that came out were the same except for the bearing on the pinion shaft where the bolt goes.

The original owner had put the bearing on the inside of the collar on the shaft which kept the shaft from engaging the bearing where the bolt is, The bolt held it all together until it came loose.

Just for giggles I tried the new bearing on the inside of the collar (between the gear and collar) but it would not go.

This one has really stumped me. Why couldn't this wait for snow to start before it let go! The grass just keeps on growing.

Kubota RCK60P-28Z MOWER

BEVEL GEAR CASE:
Part Number Position Description Serial Break
K5761-33115 100 CASE BEVEL GEAR
04015-60120 090 WASHER PLAIN
02074-50120 080 NUT
01153-50812 110 BOLT
06331-35016 140 PLUG
K5761-33250 130 PLUG BREATHER
04717-00800 120 WASHER WITH RUBBER
04711-00300 150 GASKET
K5647-33150 020 STAY CASE RH
K5647-33130 010 STAY CASE LH
04512-60120 070 WASHER SPRING
K5763-33210 030 BOLT REAMER
01073-51240 060 BOLT
K5647-33230 050 BOLT REAMER
01073-51225 040 BOLT


INPUT SHAFT/CENTER PULLEY:

Part Number Position Description Serial Break

04612-00220 130 CIR CLIP EXTERNAL
70712-33550 140 BEARING BALL
K5647-33500 120 SHAFT BEVEL GEAR
04015-50100 100 WASHER PLAIN
01133-51025 110 BOLT
7C765-51260 170 CAP
K5371-33520 180 PULLEY CENTER
K5761-33540 160 SEAL OIL
70712-33570 150 SHIM
76539-33410 150 SHIM
05712-00728 190 KEY FEATHER
K5761-33320 030 KIT GEAR BEVEL
36330-28410 040 SHIM
K5671-33342 020 COLLAR
63313-32270 090 CAP
K5645-33312 010 SHAFT PINION
04611-00520 070 CIR CLIP INTERNAL
76535-33440 080 SEAL OIL
08101-06304 060 BEARING BALL
36330-28420 040 SHIM
08101-06205 050 BEARING BALL

Pic #1 Top of box looking at the input shaft with gear and spacing collar
Pic #2 Top of box attempting to look at the other end of input shaft (pinion shaft)
Pic #3 Top of box showing the bolted end all seated and in proper position
Pic #4 Shows input shaft bearing sticking out of gear case - the bearing is seated against the shaft collar and the gear is on the shaft as far as it will go, The bevel gears are meshing as required.

One other thing I noticed is the output shaft shucks up and down about 1/8 to 1/4 of an inch.

 

[davemskinner]

Morning Bump

 

[birddogger]

In this picture:

The gear in the rear of the photo has the splines ending quite recessed, and the end of the gear collar looks like it might contact the collar on the shaft about as the splines on the shaft bottom out with the splines in the gear. Will that gear slip on the shaft pictured? That would be something to try.

 

[davemskinner]

In this picture:

The gear in the rear of the photo has the splines ending quite recessed, and the end of the gear collar looks like it might contact the collar on the shaft about as the splines on the shaft bottom out with the splines in the gear. Will that gear slip on the shaft pictured? That would be something to try.

Nice thought! I even went out to double check. The shaft size is different. There is no way the two gears will interchange.

It is sad! I'm so willing to accept that I am doing something wrong. I just don't understand what is wrong. I must have a different gear case than originally came on the deck!

 

[davemskinner]

In this picture:

The gear in the rear of the photo has the splines ending quite recessed, and the end of the gear collar looks like it might contact the collar on the shaft about as the splines on the shaft bottom out with the splines in the gear. Will that gear slip on the shaft pictured? That would be something to try.

I forgot to say thanks Birddog! All help is sincerely appreciated!

 

[birddogger]

Oh well. Just guessing going by the pictures.
Are there any casting numbers on the gearbox to help identify it?

Just checked and except for one "plain washer" there's no difference from the the 28 and the 28F.
So what gearbox is it? That would be when casting numbers would help if there are any.

 

[davemskinner]

Oh well. Just guessing going by the pictures.
Are there any casting numbers on the gearbox to help identify it?

Just checked and except for one "plain washer" there's no difference from the the 28 and the 28F.
So what gearbox is it? That would be when casting numbers would help if there are any.

Wow - quick response!!! Thanks!

The only casting numbers can be seen in Pic #3 of the first set. They are:
"4 H U 2"

I did not think they were a P/N but rather a date system. Maybe you find something out.

I will be making a round-trip to Philadelphia today to pick up a horse. I'll check in tonight

Thanks again Birddog

 

[birddogger]

Hope Vic pops back in and can help with the casting #s. I don't have access to that.

 

[davemskinner]

I'm at a loss here, but have a suggestion.

Remove the snap ring and bearing on the bolt end, and build up from the other end. Tis should allow the input shaft bearing, snap ring and seal room to install.

Then re-build from the 'bolt end". I'm interested in seeing if the rear bearing will install and wheter or not you now find the snap ring wanting to clip in place 1/2" or so towards the outside of the casting from where it's snapped in place now.

Hey Vic,

I tried that already. There simply is too much length between the gear stop on the shaft and the outside edge of the collar where the bearing seats.

I'm going to take the mess to my "local" dealer who is 1 1/2 hours away.

I'll post back with results.

 

[davemskinner]

Well it is together and running. We'll see how long it lasts this time.

Apparently the parts assembly diagram is wrong. If you put it together the way the diagram shows, there is no machined surface for the seal to ride.

The bearing goes on the inside of the collar. It is a press fit to get it there. That was the other thing that was throwing me off. The bearing taps onto the outside of the collar, but was a press fit on the inside. A soft press, but a press anyway.

I suspect the bad output shaft and center pulley were causing vibration which is why the bolt would not stay tight. I hope so anyway.

So to be clear. Assembly order is:
1. Press bearing onto the pinion shaft on the inside of the collar.
2. Place gear in case
3. Slide shaft and bearing into the case from the rear-most hole in casing
4. insert snap ring
5. Insert bearing on opposite end.
6. Insert bolt and torque.
7. Insert snap ring on this end.
8. Verify Turning torque and backlash
9. insert Seal and end cap.

 

[davemskinner]

Thanks for the kind words Vic. But really, it was the mechanic at my local dealer who helped out.

When he looked at everything, he saw that there was no way the seal would work without the smooth shoulder. Once the bearing was in the right place, everything fit.

Kudos to Ron at White's Farm Supply in Canestota, NY

Vic, Is there some process for having Kubota revise their drawings? This cost me a full week. I'd love to save someone else the grief.