John Deere X300 Rebuild

1/3rd rule: Never remove more than 1/3rd of the grass length in one cutting.

Mulching is for those that abide by the 1/3rd rule religiously. When following this rule, most outside observers would question if the lawn really needs to be mowed. In your video, you were moving right along and taking a pretty good bite. That's a lot of material for the machine to process in not a lot of time. I think you're going to find that switching to just the mulch plug will actually reduce that performance further and I don't expect it would help with processing leaves either. Mulching is more than just blocking the discharge chute and trapping the clippings under the deck. Efficient mulching is cutting the grass clippings with the outer radius of the blade and moving those clippings to the inner radius of the blade where they get re-cut as they fall back down into the lawn. The raised edge of most mulching blades is just for this purpose, and many are twisted in such a way that they produce no lift, or actually pull air DOWN in the center of the blade, encouraging this recycling action. Switching to a straight-edge blade like the Gator, with a high sail and no almost no raised cutting edge, further discourages the recycling action. Gator's are great for reducing clippings and leaves while side-discharging. And the serrated sails might do great with processing leaves. But the lack of that raised cutting edge means they will rely solely on those serrated sails to beat grass clippings to a pulp. I think there are minor clearance issues with the plastic baffle as well. Said baffle does much more than just reduce volume under the deck, it encourages that clipping recycle action and fills the front "tunnel" that is so desirable for side-discharge operation. With that tunnel open, clippings will tend to migrate to the right side of the deck and overload the right blade, leaving a line of clippings/clumps/leaves along the right-hand side of the pass. That's unavoidable on a multi-spindle deck where all of the blades spin the same direction, and that leads us into......

The 42C and 42X deck is quite versatile. It side-discharges and bags (without a blower) quite well and with a full mulch kit (plastic baffle and OE blades), mulches as good or better than any other convertible deck design. But mulching is something where the best performance is attained by using a a tool specifically tuned to do the job. Deere used to offer a deck called the Piranha Deck, it was a 3-spindle, cross-blade (6 blades!) 44" deck with the two outer spindles swept WAY back. This prevented the deck from having a forward tunnel and encouraged loading of the center blade rather than dumping clippings at the right edge. The deck could also be used as a rear-discharge but that's a different discussion. They were great performers, offered two-sided trimming, but suffered from the same problems all dedicated mulching decks do, they can't process heavy grass well. Expensive to manufacture, low take-rate, and it's placement on premium priced equipment (LX series and up) led to it being quietly discontinued somewhere around 2005.

Enter the Freedom 42, on the LT and LX series tractors, a counter-rotating, parallel (no offset) twin spindle mower deck, with permanently closed in blade chambers. The parallel counter-rotating blades necessitated a cogged timing belt drive that required much more discipline to service properly. Mulching performance (and turf striping!) was second to none really, at least in a multi-spindle design. The counter-rotating blades meant that clippings tended to migrate to the center of the deck, where they would get distributed equally back into the two blades for recycling. When over-loaded, you could get a streak of clippings right down the center of the pass, but everything about this deck was optimized to mulch. While Mother Deere was clear that this deck was intended for well-manicured lawns that were mowed frequently, dealers still sold them to the guy with every vehicle he's ever owned (save the one he drove to the mower shop) on blocks (maybe) in the yard. Striking solid objects with the blades would usually result in a broken timing belt, and bent blades. Almost always over $100 in parts, even 20 years ago. Plus, setting the belt tension properly was absolutely essential to getting it to track around the drive properly and there were many instances of a DIY customer ignoring the included instructions and returning to the dealership with a brand-new, broken belt, and sour attitude, as the broken belt meant that the new blades (remember, counter-rotating, interference design....) were now damaged as well.

The Freedom 42 was discontinued when the X300 series was introduced in 2006. The 42M option for the X300 was a new shell design that sought to alleviate the mechanical booby traps (from the Freedom 42) while retaining as much dedicated mulching performance as possible. Still a counter-rotating design, it offset the blades exactly like the 42X (and most other twin-spindle) deck did using a double-sided belt drive and a couple extra pulleys. This eliminated the mechanical blade interference from the Freedom 42 design, and the timing belt. While the deck was much more tolerant of abuse, it still suffered from the same problem it's predecessors did. You couldn't really wade into 12" tall grass and expect this deck to perform. You would get clippings and clumps if you went on vacation and came back to heavy growth. And if you were mowing frequently enough to get great results with a dedicated mulching deck, the 42X convertible design would mulch just as well to the untrained eye, really only giving up the two-sided trim ability. Owners liked options as well, and you lose the option to bag or discharge with the 42M. So the 42M option went away when the X300 series was refreshed a few years back.

All multi-spindle mulching deck designs are a compromise. You must give up some clipping recycling action to accommodate the extra spindles/width. There are some phenomenal mulching designs that can process a bunch of grass/leaves, even better than the above mentioned decks. But they are all single-spindle designs. Toro Super Recycler walk-mowers, for example. Or a Deere TerrainCut 7700/8800. Get out your wallet for one of those.....

Your lawn type dictates what's best for mowing height and clipping management. On non-irrigated, cool-season grass, cutting in the upper end of the recommended range for your grass type(s), then you probably aren't going to leave visible clippings, even in side-discharge mode. When the weather is cooler, and the soil is moist, cutting in the 2-3" range produces that awesome "barefoot" lawn. But the grass is likely growing vigorously in these conditions and to remain within the 1/3 rule, you will have to mow often, usually more than 1x week. Raising the height will ease up on the mowing frequency, but the turf will not be as dense. You must find balance in the Force Padawan. When summer temps are consistently in the mid to upper 80's or higher, this stresses cool-season turf and it will weather the summer far better at a taller height.

And y'all thought I had a chainsaw problem...........

 

Those spindles aren't terribly difficult to remove the center shaft from and clean it out. Gives a good view of what kind of shape the bearings are in too. Make sure the bearings do not have inner dust seals installed.

 

Very rarely unless you "calibrated" the deck height. It's usually significantly lower. The 42C/42X is easy to measure through the discharge opening. But if the deck is raked forward properly, the most accurate measurement is up front, with the blade pointing at 12 & 6 o'clock. Measure the tip of the blade to the ground. You can cut some "gage blocks" from scrap lumber, use a brick, etc. as well. Creative is good. There are dedicated tools for this task but..... This is also a good way to observe what 1-2 psi adjustment/loss in a tire (especially a rear), does to cut height.

When adjusting the deck level, start with 4 properly inflated tires, level side to side first, then front to back. Front edge of the blade should swing 1/8"-1/4" lower than the back. Calibrating the height can take a little more time, close is good enough, I recommend mental adjustments for minor discrepancies.

 

That's exactly how many golf courses, parks, etc. deal with leaves. Just on a little different scale.

If you can get into them before the leaf cover gets quite that heavy, you'll see even better results. Note the amount of "blow-out" coming from the right side of his machine.

There used to be leaf baffles or anti-blowout baffles for these decks. Not sure if they are still available. But the plastic mulch plug takes care of a lot of that.

 

I really doubt that little bit of damage was the cause for the clumps. I have seen far worse! You were eating quite a bit of grass in that cut. Reducing ground speed, or even better, picking up your cut height would have given a clean pass. Even a 1/2" can make all the difference. WOT is the way.