Hobart L800 Mixer
I need some advice on a Hobart L800 mixer. It is at a pizzeria that mixes heavy dough daily. The original complaint was that it leaked oil from below the main (planetary) shaft (not the agitator shaft). I ordered an oring and chimney and replaced those and that corrected the leak. However, when I pulled the main shaft I noticed that it was worn at the bottom bearing. The bearing looks good but it is very loose on the shaft. It can be pushed easily up and down on the shaft. There is a lip on the bottom of the shaft (see photo). Otherwise, the mixer is quite and runs ok.
My question is: replace the shaft and bearing? My cost on the shaft alone is $500+ from Hobart. I just don't want to have the customer pay for something he doesn't really need.
Been too long since I've wored on the big uns.
That area to the left of the lip- what goes there? The book shows a thin-ish spacer up against the inner race of the main shaft bearing.
I'm assuming the planetary would be to the right, and the chimney to the left, yes?
A bearing of that size should need to be pushed on fairly hard, on to the diameter that it rides on.
That bearing slides down into the transmission case. There is nothing below it. The planetary slides up to the step on the shaft below the bearing. The bearing won't come off unless the lip is filed down.
Then the bearing inner race was spinning on the shaft, and has severely worn down the shaft. To make it right, replace the bearing and shaft- that's a lot of wear. I'd bet that when you move the bearing down to just above the lip, it is possible to "wobble" the bearing a bunch.
What that amount of play, in that area will do, is allow the small planetary gear to walk up against the ring gear too hard. In fact, I'd bet if you had the planetary off, and then grabbed that main shaft as it hangs down, and give 'er a good horizontal tug back and forth, you'd see or feel a bunch of play. never a good thing with highly loaded bearing assemblies.
If your customer was planning to use this mixer forever, you'd want to replace the bearing and shaft. If they were low on funds and wanted to make it by for a year, it would fly, except that you'd be damaging the ring and planet gears, and to a lesser degree, the transmission gears.
In addition, any oil that gets by the chimney will not be held back by the bearing, as there is now a path for that oil to migrate downwards by way of the loose inner bearing race. Put some Permatex sealant on the large flat washer at the bottom of the planetary when you reinstall it to keep the oil in the plantary, and not drip down into the bowl. Check the *planetary* oil level every month or two and insure the oil level doesn't rise too far.
You *did* replace the sight glass window in the transmission case, yes?
Yes. It was completely black.
The customer depends on this to mix all of his dough, so I'm sure he will want it fixed.
Thank you for the help on this!
Not a problem.
Yeah, while it does cost a lot, these mixers are work horses, and it should be good for another hundred-thousand miles when you're done.
If it has not been done lately, while I had the planetary off, I'd be replacing the shaft seal on the bayonet shaft, even if it was not leaking.
It's cheap insurance and a lot easier to do with the silly thing upside down.
Wait until you have to work on one of the V1401 double reduction planetary units. Two guys and a jack to get it off and on without dropping it. Heaaaavy!
I've actually done that a time or two. If you can find a scrap Hobat 5801 meat saw pulley, the agitator shaft slides perfectly into the bore of the pulley. It makes it a lot easier to handle. I usually run the bowl yoke all the way up and lay a couple of short 4 x 4's across it to make platform to support the planetary.
AWESOME. I actually have one laying around the warehouse and was wondering why the hell it had no saw attached to it. lmao. Its little tricks that can save a back!
Originally Posted by samservice