New 3240 owner with stuck transaxle issue

[ol'George]

Sounds like a plan

[snoel]

A light "tap-tap-tap" with a small steel head hammer, around the "seam", will usually break the bond, from the slight vibration, shock. It may take more than you expect, so be patient, and not get too ambitious with the hammer! Others, may have a better solution.

[t6430gr]

I'm trying to not use the hammer as I usually see it as a tool of last resort. Of course, I do have a nice variety of smashers! Since the material is cast (brittle) I'm avoiding the destruction of this as much as possible. I prefer to pull this straight off as there are two shafts that are supported on each side. I don't want to twist this into submission because I could cock a bearing. I want to be aggressive without destruction.

That can be a delicate balance when one is overcome with impatience!

[Thumper807]

Originally Posted by Oak

Here is the link to the manual. Lots of good stuff here.
http://www.mymowerparts.com/pdf/Cub-...epair-Manuals/

Now you guys got me thinking I need to pull mine and check it......maybe I'll see how difficult it looks first. Lots o pictures please.

Thank you very much for the link Oak!

[t6430gr]

Well gents, here's the scoop om my issue. I was able to finally get this apart, but I wish I hadn't as our suspicions were correct. To get the case apart, I reinstalled the four bolt hub, and also the two axle bolts that attach to the frame. I used two large C-clamps to push/pull the axle against the case. It popped right open with me beating the case to death! One hint here, before opening your case, use a flat file or fine grit sandpaper to remove the rust on the axle shaft as the clearance on the bearings is tight. If you don't you'll encounter resistance pulling off the outer case plate and again when you pull out the axle shaft assembly.

Needless to say, depression set in a little bit once I got it apart. From the pictures, you'll notice the bolt hole and exposed threads. If you can peak inside your case with a flashlight through the dipstick hole or a small camera, and you see exposed threads, you are experiencing the same thing. This is where you stop and make sure you have a 12 pack of beer to get through the next couple of days. Note from this view, you can see the clearance between the drain plug and the diff gear. Before you try to pull out your diff assembly, make sure this plug is backed out first. Also, some good news I guess. When you take your diff assemble out, you don't need to remove the hydraulic pump. After the case is open, the next step is to remove the diff lock. at that point, you can start to pull out the diff assemble and axle shafts. The output shaft that connects to the ring gear and rides on top of the diff gear will start to come out too. Just wiggle the output shaft an inch, and pull out the diff assembly an inch. Eventually, the brake disk will come off as the output shaft extends through the case and turns the brake disk. Note the orientation of the disk before taking it off. As you continue this back and forth motion with the output shaft and diff assembly, the output shaft will disengage from the ring gear and the ring gear will ride on a smaller diameter of the output shaft. These two connect on splines. Once the ring gr=ear is loosened, you'll notice there is more freedom to pull out the diff assemble without the output shaft's need to ride out any more, and should be able to clear the large diff gear. Just be careful to not force anything here. If you feel resistance, you probably need to push the diff assembly back in a little and pull out the output shaft a bit. If you pull the output shaft totally, it's no big deal. There is a flat thrust washer behind the ring gear that you'll lose along with the ring gear itself.

The gears inside my diff assembly have a pretty worn wipe pattern and will need to be replaced eventually. The ring gear is also damaged. I tried to file off the burrs on the outside edges of the damaged teeth, but the gear was harder than my files. I had to surgically grind them off with a Dremel tool and cut off wheel. That made short work of that task! At this point, I think that I can get away with putting this back together and nursing it along for a couple of years. Eventually I think I will buy a new set of gears for this and rebuild it like it needs to be. My goal is just get it going for now, and a rebuild will be better suited in the off season.

Another couple of comments before I go. I found replacement grade 8 bolts (3/8" x 24 tpi) at my local hardware store. Before installing them, I sprayed out the thread holes with brake cleaner and put a drop of Loctite thread locker on each one. The bolts I purchased were just slightly longer than the originals. If I had about another 1/4 inch, I would have plenty of meat to attach a nut on the extra length for good measure. I don't know if that would be necessary or recommended, but considering the fact the bolts tend to loosen, I might do that when I rebuild it next time. There was enough clearance between the diff lock and the nut I tried to make that feasible. These bolts are supposed to be torqued at 220 - 280 inch lbs. My 3/8 drive torque wrench stopped at 250 inch lbs so that's what I torqued them to.

So, last night I got everything put back together except for one last item. It seems I have misplaced one flat bearing washer that goes between the diff lock and the next bearing on the outer case cover. Don't know what happened to it, but between myself and the wife tripping over tools and other items on the garage floor, it's hard telling what happened to it. I guess I'll have to check at the local automotive store for a replacement or order another online. I can't put this back together until I find it, so I went to bed last night ticked that I lost it. It's part number 24 on the parts diagram.

[ol'George]

I am surprised @ the wear on the 4 spider gears, chipping I understand, but one heck of lot of wear on the contact surfaces, for the stated hours.
It appears they are through the case hardening in places.
So you are going to take it easy and avoid any "hole shots" then as time permits replace the worn items in the off season,----reasonable plan.
Wondering if nutting or safety wiring the bolt heads, is advisable.
The bull gear does put all the driving motion through those 4 bolts, I sure would like to see @ least 6 or even 8 bolts taking the strain.

[Sam Mac]

First time I've seen the inside of one of these. I wonder if you could put longer bolts in it and after torqueing it put some lock nuts on the back side? Don't know if there is clearance or not, just a thought.

[t6430gr]

Originally Posted by Sam Mac

First time I've seen the inside of one of these. I wonder if you could put longer bolts in it and after torqueing it put some lock nuts on the back side? Don't know if there is clearance or not, just a thought.

I agree. I had the chance to get 1/2 longer, and I probably should have to put nuts on the back. The size I purchased were about 1/16 longer than the originals. I think that locking washers might work if they could clear the diff lock unit when it engages. I did check and a nut would clear the diff when it engaged. I hadn't thought about wiring them, but I would probably need a machine shop to modify some bolts for me, as these are grade 8 and pretty darn herd.

I will baby this along and maybe work on it this upcoming winter when I won't be mowing multiple acres. I'm thinking more in line on something Oak does to his, meaning really dig into it and replace all gears and seals too. I can see plenty of oily dirt on the deck lift spool and cylinder. I'm sure they need rebuilt too.

[t6430gr]

Originally Posted by ol'George

I am surprised @ the wear on the 4 spider gears, chipping I understand, but one heck of lot of wear on the contact surfaces, for the stated hours.
It appears they are through the case hardening in places.
So you are going to take it easy and avoid any "hole shots" then as time permits replace the worn items in the off season,----reasonable plan.
Wondering if nutting or safety wiring the bolt heads, is advisable.
The bull gear does put all the driving motion through those 4 bolts, I sure would like to see @ least 6 or even 8 bolts taking the strain.

I agree whole heartedly. All of that wear translates into a ton of loosey goosey in the axle play when I rotate the tires back and forth in either direction. I'm really hoping that the hydraulic filters do a good job or I'll be rebuilding it too. I guess all this work is a lot cheaper than the comparable cost of something new. I don't usually buy anything new in this kind of price range. I tend to buy cheap, fix it, and take care of it. I paid a guy $1,300.00 for this mower because I was impressed how clean it was. I have never purchased a mower this big or complicated and I think the seller knew something was wrong. He was just damn lucky that this mower drove nice when I was on it! It was a nice mower in a nice neighborhood with a well groomed lawn and he was a very nice guy. I doubt he was clueless to any issues as the extent of wear indicates that this has been going on for awhile.

I can tell you though, the transaxle is on my garage floor right now, reassembled, and the fresh sealant is drying. I tried to turn the axles after I buttoned it up, and it feels so much more free!

[Sam Mac]

It will probably be trouble free for the rest of it's life. This is part of the deal buying used, you have to figure you will need to put some time and $$$ into it. In the long run it seems to work out.