How do i remove the planetary on a D300 mixer

I don't think they ever made a video for that.
The grease in the D300 is sticky and runny, and has to be removed out the top once the bearing plate is removed. On the top of the main shaft is the first gear cluster and a bevel gear beneath it. If necessary, use a pulley, BUT KEEP IT AS ONE ASSEMBLY.
Once it's out, the rest comes apart easily. Just lay out the components as you find them. Clean and inspect.
The first gear is made of the bevel gear as a base, a center hub with an outer ring gear, and a stepped cover on top that sits under the top bearing. Between the ring gear and the hub are 10 rollers and spring plates which bias the rollers into the shallower end of each roller seat.
You can get instructions and diagrams here.
https://my.hobartcorp.com/resourcecenter/Pages/FilterByModel.aspx
search model number d300. near the bottom of the options is form F-3492-N. That has detailed instructions for the older version.

Tap drip ring off, punch out pin through planetary. Remove back cover, unclip black wire and white wire from rear control board. Tip it upside down, remove pedestal. Undo 5 screws around where planetary came from, undo the remaining 4 screws on underside of gear case, pull the cases apart.

Hi ALLENJUJU. To replace the agitator shaft will require a significant amount of extra effort, but will be well worth it in terms of gratification and reward for being able to successfully do it yourself. First, I’ll assume your mixer is no longer under warranty. Second, I’ll assume you have your Repair Parts manual on-hand. If you're lacking one, you can download a PDF version from the KA website at: http://www.kitchenaid.com/flash.cmd?/#/page/home.
Click on Customer Care>Locate Manuals & Guides> Enter the 6 character model number, in your case use KSM50P (Your K5SS mixer falls within this manual), and select the first file KSM50P.pdf (438.31 KB) listed under Parts List (4) and then check to verify this matches your mixer model.
Turn to pages 4 & 5, titled: “Case Gearing And Planetary Unit” which shows you an exploded view of all the mechanical parts and assemblies for your mixer.
I highly recommend the following website that provides you step by step instructions with pictures (worth every bit of a 1000 words) to gain access to your planetary housing and agitator shaft. The mixer displayed is a different model (tilt-up) than yours, but the ‘insides’ are the same.

• http://www.artisanbreadbaking.com/discussions/kitchen-aid.htm

It would be helpful to have the following tools available as you begin to disassemble your mixer: a flat screw driver, a small Phillips screw driver or a punch drive, a pair of retaining clip/ring pliers, and a hammer.
You will need to remove the Planetary Drip Ring (Illus. No. 42) and Pin (Illus No. 25), which secures the Planetary Housing (Illus. No. 33) to the Center Vertical Shaft (Illus. No 19). (See pictures 6, 7 & 10, 11 from the link).
You’ll need the punch drive or small screw driver with a smaller diameter than the pin, a hammer, steady hands and plenty of patience. Rotate the planetary housing to expose the retaining pin with the vertical (center) shaft.
After removing the Planetary Housing, remove all the residual grease from the 18 tooth Agitator Shaft Pinion Gear (Illus. No. 47), which should expose a Retaining Clip (Illus. No. 61), which will need to be removed. With the Retaining clip removed, the pinion gear and Shim Washer (Illus No. 45) should easily slide off the top of the agitator shaft and you should be able to pull the agitator shaft down through the planetary housing bushing.
Take your new, replacement agitator shaft (be sure you’ve got the lower groove pin ordered, too, and insert through the bottom Planetary bushing. Replace the shim washer, 18 T Pinion Gear and Retaining Ring. Grease up the whole works with new grease, and reassemble the opposite of how you took it apart.
Here are five potential online vendors in no particular order: RepairClinic.com; mendingshed.com; searspartsdirect.com; partstore.com; and Grainger.com (for grease). You should search for ‘food grade grease’ online (although I’ve seen automotive bearing grease used too – your call). Prices can vary widely between vendors, so do some comparison shopping.
I hope this helps - hslincoln, Burke, VA
If this solution has been helpful, please rate it, thanks! hslincoln

sounds like you sheared the key on the on the ptanetary to main shaft. remove planetary of mixer. you will see how main shaft is keyed to planetary. replace key reassemble , and you will be mixing agian, dont forget to vote, thanks, monomoy

The transmission center shaft seal/chimney is bad.You need to tear the transmission down in order to repair,let me know.

Using flat screwdriver, remove upper main shaft cover screws (3 of them) to expose shaft nut. Using 3/4" wrench, remove nut and washer on top of main shaft. Using 9/16" wrench, remove double nuts and washers on both small shafts (the double bearing-retainer plate can stay screwed on). Using flat screwdriver, carefully pry stainless drip ring from lower housing (it's just press-fit). Using 3/4" wrench, remove acorn nut and locknut from bottom of main shaft (hold on to the housing, it's gonna drop down and it's HEAVY). Using flat screwdriver, remove cast iron cover hold-down screws (4). Place wood block over end of main shaft bottom to protect threads, and tap upward with a hammer. Don't go crazy with hammer, top housing could go flying. It may take several taps (it's on tight). Increase force slowly so as to minimize chance of damage. Prying out the two press caps from upper housing with a flat screwdriver will give you a place to stick your fingers to lift cover off once it's tapped loose.That'll get the top housing off. But planetary shaft isn't coming out without complete transmission dis-assembly. Better get a book, or better still, hire a pro. Just be careful with Hobart factory repairmen. I've had a VERY bad experience with a VERY highly-paid factory tech. You may have better luck than me, but I'd ask around at a few restaurants and search the 'net for an independant repairman. They tend to work harder for less money than factory guys, and take more pride in their work. Hope this helps!

hi

there is a ring clamp on top of the main worm follower gear on the drive shaft. you might not see it due to the grease.

you need to get one of those weird little pliers with points on them to spread the ring clamp to remove it. Then the gear is just friction fit on the shaft...it's pretty tight. I carefully used a screwdriver to slowly separate the main follower gear from the lower gear and it goes up the shaft....

after a bit you can wiggle the follower gear by hand and it will come up. Then you can see there is a pin holding the drive gear underneath it in place. The pin in my mixer was actually bent (must have been some tough dough).

then you reverse the process to put the gear back on -- except that the top follower gear has to go on the pin in the right orientation or the ring clamp won't fit.

buy your parts from mendingshed.com

hope it helps.

Thats the center shaft and if it moves back and forth the lower bearing is bad or the shaft has cracked.You need to remove all 3 shaft assemblys. if you already removed the gears on the center shaft then you need to remove the shifting yoke---turn power off to machine then take the screws off the trim plate where you shift speeds,you might see a switch that sits up on the shifter cam,remove the screws and put switch aside,take the 4 allen screws off and pull on the shifter(it will come out).If you didnt already drain the oil do it before you mess with the shifter.after the shifter is out grab the upper left gear assy. and the gear assy. below it,rock both gear assy. and pull up,they will both come out(you might need some force)once out remove the remaining gears on the center shaft and remove the shifting yokes.you then need to remove the planetary (lower part of mixer)if not already done,then pull the shaft out from the bottom.any questions let me know.

I called KitchenAid about this issue with my mixer. The agent on the phone told me they are aware that it tends to happen to some mixers after they sit for some time. Basically, a "lifetime" of grease has been packed into the assembly and it is normal for it to release grease on occasion. I was told to run the mixer at 10 for at least 2 minutes to get it going and I should see a reduction in the oil leak. I had about a tablespoon worth of oil dripping down off the assembly. I was told that if over time it seemed to amount to about 1/4 cup then I should call to see about repairs due to a potentially bad seal. I was also told that the repair for that would most likely NOT cost the same as a new appliance.