My Hobart D300 mixer appears to be leaking oil/grease

Hello Chardanio,

I understand you are wanting to give you Hobart D300 an Oil change.
Here are the steps you need to follow:

1. Locate the oil plug on the buttom of the head next to the plantary and the bowl slides. It will be a bolt just like on you car.
2. Run you machine for a short time in order to get the oil warm so that it will flow out of the gear box.
3. Remove the bolt so that the oil will come out into a container.
4. Once drained you reinstall the bolt
5. Remove the top of the Head (2 screws)
6. You will locate a plate that has a few bolts holding it on. On that plate there is a little tin cap you can remove it with a little flat screwdriver. Becarfule not to damage it you will have to put it back in the hole after you fill the unit.
7. Install 70oz of 140 weight gear oil. It is also thick you may have to push it in to the unit then run the unit and check the oil sight. Add slowly as you do not want to over fill the unit.
8. Replace the cap. (if damaged you will need to order a 00-064871 from the Hobart Corp. at 1-800-446-2278 or another part company)
9. Replace the top of the Head and you are done.

Turn on the unit and us it as you have before.

If you have any other questions please post to this thread.

Thank you for using FixYa hope this helps.

It uses grease which breaks down over time. The transmission has to opened up and all of the old lube removed and replaced with fresh lube and the bottom seal replaced. Contact your local Hobart office. www.hobartservice.com to locate your local office.

Transmission uses #0 weight grease, best to get direct from Hobart (their grease is the correct weight and approved by U.S. FDA & USDA as safe for use in food equipment) but if you insist on not doing so, at least obtain an Extreme Pressure #0 grease and don't overpack the transmission, I believe it should have 35 oz. if memory serves right.

Uses a heavier grease for the planetary gear, use #2 weight. Don't need much, just a light coat on the planetary gear.

Bowl lift rails use medium weight oil, again use food grade oil supplied by Hobart.

Goto hobartcorp.com,create a username and then you will be able to find out what your looking for.I know that these mixers used oil when they where new but now changed to grease.Any ? let me know as im a hobart tech a repair these often.

You have a gear with broken teeth or one sliding out of place because the brass shims are eaten up. Hobarts have what is called a planetary, round head where the grease caps are, and there are no clutches for this planetary. These units are not made to change gears while unit is running (#1 problem of gear failure) (#2 is overloading the bowl) Hobarts need a really stiff GREASE, not oil. If you decide to take the planetary apart, get all the syrup out and replace with a stiff axel grease. It is a very difficult job replacing a gear & ALL the shims. The round head where the grease caps are can easily be removed to do this.

Depending how old the mixer is they used to use oil,now they use grease.Regardless it sounds like a seal is worn.Where is it leaking from?

You can put in a all purpose grease. I use MOBIL 1 Synthetic Grease (RED IN COLOR) and it works fine -- you will need 3 tubs of 16oz's each tub. The cost is 30.00 or so. Make sure to get all of the old grease out and pack around each of the trans and worm shafts with the grease, then pack around the MOTOR GEAR and then put all back together. While running it make sure you can see the grease and hear the noise of the mixer through the 2 caps that are FILL caps on the head of the mixer. ALSO, you will find that you will lose 1st gear IF you have tigtened down too much on the LOCK nut, SOOOO loosen in small increments until all 3 gears are perfect and strong. ALSO, the key to noise adjustment is to Tighten (WHILE MIXER IS RUNNING) slowly the large nut that controls pressure on the worm transmission. The general rule with tigtening this nut is to tighten it till it will not tighten and then back off the nut -- IF the unit when starting does not run or it seems bound up when you first turn it back on, THEN you have tightened it TOO MUCH, SOOO back it off again (loosen it) until it starts smoothly and when you turn the mixer OFF it should come to a slow stop and not abruptly stop the mixer. Hope this helps some of you out there trying to do your own adjustments --

Sounds to me like the shifting yokes are locked up,or a broken shaft.Is there any noise?

this unit uses grease if it is leaking out the grease has broken and needs replacing

Thanks,, great info..

I took mine all apart and the oil was just at the point of turning into grease. Nasty,, brown smelling ****.... I cleaned it all up and just used a sync 50w gear oil.. I over filled it and the extra ran out of the motor end of the gear box... It might have been about 2 table spoons too much.. Now it does not leak anymore.

Thanks again,, jaybeesee

Daniel from Penokee