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Need advice for a Hobart a-200T

risenshine's picture
risenshine

Need advice for a Hobart a-200T

Hello,

I just bought this used mixer and noticed that there is a rhythmic sound (almost a bump)in all speeds. I'm suspecting it might be in the planetary gear section but can not get it apart. I've taken the gears and grease out to inspect and all gears look pristine in there... Also when the gears were out, I did not hear that sound... Hummm  It almost sound like there is something in one of the gears.... some foreign body or a chipped tooth...  ( in the planetary) ?

The planetary does not just drop off the shaft one the two retaining nuts are removed. I'm wondering if the youtube video "A200 Hobart Service" showing the dropping of the planetary assembly has changed in the new models?

Also - I may just take apart and degrease everything.. other than seals is anything else a "must replace" at this point?

Thank you in advance..

Tom

risenshine's picture
risenshine

Well.. I contacted Hobart to see what they would say. Not good.. They said on the a200 model that the planetary sometimes seizes on the shaft and have to cut off... Planetary costs about $500 and the shaft around $100. I'm contacting a machine shop to see if they can drill out the shaft from the planetary...  Hobart asked if I had heated it up.. That would be a mess...burn all the paint off the planetary and who knows what. Anyone else here had these problems and any advice?

Bob Marley's picture
Bob Marley

You might try posting your question here:

http://www.cheftalk.com/f/22/cooking-equipment-reviews

risenshine's picture
risenshine

Thank you for the advice.. I did just that!

 

risenshine's picture
risenshine

Ok.... I got this !$#!^! thing apart... It was like brain surgery to do all this.. If you've seen the replacement cost of working on these things you can soon run up expenses that cost more than the mixer.. Especially if you use Hobart parts.

I decided to use after-market parts where I could. I went with a company called "National Band Saw". There was a company with lower prices but it was one of those companies that had no real store front or address, no\ real service people etc.. and I felt NBS was worth the difference. In fact I was able to call NBS and talk with the tech person ( their engineer) about the quality of the shaft I had to replace and he personally knew the specs and that it was properly hardened etc..

Ok.. the culprit was RUST... A mixer, from the outside that looked very clean... at some point had something corrosive get below the ball bearing/ grease seal and drip down the shaft. This emphasized the importance of routine /periodic basic maintenance. It is not difficult to pull the gears out of an A200T and replace the grease and inspect the gears for wear. Gears and bearings are surprisingly reasonable in the aftermarket prices. A planetary shaft from Hobart runs about $350 and aftermarket runs about $140. Bearings are $5 - $10.. Grease is $10 - $15 per tube of SYNTHETIC.

It is going to cost me about $300 to put this all back the RIGHT way.  I paid $1000 for the mixer  so I'm well within its value... At some point you are probably best to just sell things for parts value.

Looking at the pitting on the shaft, I don't think it could have been saved. I had to use penetrating spray to try and dissolve/ lubricate whatever was in the space between the shaft and planetary assembly. I used a hand sledge to force the shaft through.. under the seal is a bushing with a o-ring. This too was seized.

On the inside of the gear box, all had been removed except the remaining gears on the planetary shaft, the axillary attachment gear/assembly, and the post the shifter slides on.  With the planetary off,  the shaft was loose, so I had to hold the shaft down with the weight of the sledge on the raining gear.. and a regular hammer to strike the shaft up.. I heated the shaft and hit it with more penetrating spray.. and it took 15 - 20 good strikes to push it through the bushing. This ruined the bushing and is a Hobart only part.. and about $47 dollars.

it is now all apart... 

The "must replace parts" were the planetary shaft, the bushing, o-ring, Grease seal. The bearing felt good but only cost about $6 to replace so there was no reason to take a chance.  I also had to replace the lower key for this shaft, a castle nut that protects the end of the shaft...

The Key for the wormgear shaft was also fractured.. this may have been what was causing the "thumping" sound as the mixer operated without load. I knew from the sound that this was something that would progressively get worse and possibly cause more damage.

I'm a believer in synthetic lubricants. I talked with a guy who worked in NASA as a lubrication engineer and he talked about the superiority of synthetics. Regular petroleum starts to break down immediately. The grease in my mixer had already separated into liquids and solids... Not totally but in the areas most important.. around the gears the would bear the load/ wear. Synthetic molecules do not breakdown like petroleum. Get synthetic in your mixer!

I also replace the gasket on the transmission shifting assembly. Just using synthetic should avoid any leaking of the emulsified oil from petroleum greases, but for $2.. it is the ounce of prevention. 

Anyone who has brought a used mixer needs to beware. I think Hobart is one of the best names in mixers. But maintenance and parts costs are very high. Commercial mixers take a real beating. My mixer was used in a place that made pretzels.. this is one of the heaviest doughs to mix. They have perscribed structural limitations on the type and quantity of dough they can handle. I believe many places probably do not even understand let, alone follow these limits. In a well maintained mixer the the transmission should be about as loud as the motor ( under no load). A noisy transmission could be just grease that is long overdue for a change. THAT could also mean lots of wear on the gears that have not been properly lubricated or much worse. Buyer Be Ware!

There is normal wear.. that is to be expected. A bronze worm gear that is softer than the mating worm gear. Seals, and O-rings, bearings, Grease, Switches, cords. As things wear out, it puts stress on other areas causing more wear. This is why routine/ periodic  maintenance is the cheapest route to go... Take care of your mixer and it will serve you for a life time. Especially these commercial machines designed for 12 - 24 hour / day use. But, no matter how well it was designed and built, it will slowly tear itself apart, if left to the fate of time and wear.

DaChef's picture
DaChef

risenshine : Really appreciate your thoughts on your A200T.  I am in the process as I type this comment of breaking apart mine and trying to remove the old, worn Lubricant/grease from the top housing of this unit. I have stripped out all the gears and degreased all the gears to remove all the grease. I took all the parts home and in the back yard soaked them in gas, ok I used petro to clean them, which did an excellent job, left them outside to get rid of the smell and dry up. Brought them to work at 5 a.m. and ready to pack them with grease. I will try to use a penetrating spray to remove excess grease in the cavity on top, but will not be totally clean. Once reassembled, both top and bottom, I will be pulling motor out and checking bushing, etc.