The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Diagnosing the Ills of a KA K5SS

drfugawe's picture

Diagnosing the Ills of a KA K5SS

I'm in the middle of what I think is a straight-forward repair job on my elderly KitchenAid stand mixer (K5SS), but I think I'm at the point where I'd profit from the collective wisdom of other KA users on this forum. About a week ago, I was about to put my unit to work on its weekly bread dough, and I had just put the dough in the mixer bowl – turned the machine on and as soon as the hook hit the dough, the hook stopped – motor kept running, no strange noises, but the torque was not there. Over the years I've heard a lot about the nylon gear that's intended to act as a fail-safe to protect the rest of the mixer – so I immediately stopped it, and proceeded to research how to get inside to check on the gear in question.

The more research I did, the more I was convinced that the behavior of the mixer indicated that it must surely be the nylon (plastic) worm gear that had stripped thereby causing an almost full loss of torque, while the motor was not affected. After a few more hours, I had found enough good instruction on the web that I felt comfortable in starting to dismantle the mixer. Without getting graphic -or going off-course- it took me a full 3 days, and at least 3 trips to the hardware store before I was into the guts of that baby, and could see the internal gears.

Here's the deal – now that I'm able to see all the inner workings, I frankly don't see any damage on that worm gear, or any other gear in there! And the more I looked at that gear, the more it looked like a steel gray metal, not the yellow material in all the photos and videos. Is there a chance that my K5SS actually has a metal worm gear? Or did the old original worm gears come in a metallic color? And is it possible that this gear has been damaged and that I may not be able to determine that fact?

I know some of you have done this same job and had similar experiences – if the worm gear is damaged enough to lose torque on the hook, would I be able to see that clearly on the gear? And if it's not the worm gear causing the problem, what might it be?

Thanks for reading and I hope to hear from a few of you – I appreciate your assistance.

clazar123's picture

I believe this will be similar to your model mixer. The innards are pretty similar on most of the mixers. If not, take a look through You Tube. I know my handyman (also known as husband) has been inside my mixer, which is now 36 years old and functions wonderfully. I do remember the grease-the innards looked absolutely new under the grease.

Search google for : kitchenaid stand mixer schematic

I know he found replacement parts and a schematic but that was about6 years ago already. Or more?? I don't remember You Tube being involved.  The gears can be subtly worn or even cracked-it can take some pretty close inspection.

Good Luck!


drfugawe's picture

Thanks clazr,

I agree with all you say - that video was the one prime instruction piece I used in my teardown (although it was not quie as easy as the tech in the video made it seem!) and I'm also using mendingshed for my needed parts - really nice prices!

Much appreciation.


GAPOMA's picture

I too have a KitchenAid K5SS that's old enough that I don't remember how old it really is.  At least 15-20 years.  I've been using it to make bread for about that long too, so it's definitely seen some abuse.  

Over that time I've had too replace the worm gear twice.  The first time about 8 years ago, the second time about 6 months ago.  I honestly don't remember whether the original gear was metal or plastic (I think plastic, but it might have been metal), but I know for a fact that the replacements are plastic.  It's not really too hard to do, but it's kind of messy.  Get a new gear, and get some new grease too.  (I think if I do it again, I'll also get a new gasket.)  Basically I follow the instructions on this page (or one similar):

The first time it took me quite a while, but the second time I was pretty fast (30 minutes or so).  I would recommend taking out all/most of the grease.  Doing this really helps you to see what the problem is, and makes it easier to work with.  You'll need to replace it with the recommended new food-grade grease.  (I bought a can of grease the first time, and it's enough to do at least 5 repairs, so I'm set for life!)  I also now always keep a spare worm gear on hand because I know it's eventually going to break.  But it's definitely worth repairing!!!  FWIW, I recently bought a new KA mixer for my second home in AZ, and the new mixers simply aren't as rugged, and can't handle the dough capacity that the old K5SS could!!  I'm NEVER getting rid of my K5SS!! ;-)

You ask whether you should be able to see damage on the gear.  The anser is yes ... but ... there's an awful lot of grease on there so it may be hard to see.  In addition the damage may be much less obvious than you might imagine.  Based on the symptoms you describe, I'd be really surprised if replacing the worm gear didn't solve your problem.

- Greg

subfuscpersona's picture

...not plastic.

Model K5-SS was made by Hobart (not Whirlpool, who purchased the KitchenAid brand from Hobart in the mid-1980s). Hobart did *not* use plastic for the worm gear.

I've owned (and used) my Hobart-made K5-SS for over 20 years. About 8 years ago I took it to a local authorized KitchenAid repair center for servicing. The repair person raved over the quality of the mixer. No parts were replaced - just regreasing and a little cleaning.

I have the Hobart Service Manual for the K5-SS. It is in Adobe Acrobat (pdf) format. If anyone would like a copy, send me a PM and include your email address in the PM. I will email you the manual (as an attachment) within a few days.

GAPOMA's picture

Definitely would like to have that!


subfuscpersona's picture
  1. Sign into TFL.
  2. In the upper left corner, click on Messages
  3. Click on New Message
  4. Address your message to me (subfuscpersona).
  5. Use a subject header re Hobart K5SS manual so I will not inadvertently send your email to my junk mail folder
  6. Include your email address in your message so I can reply to you.

I will send you the manual (as an attachment to the email) within a few days.

Yours - SF


cyclebread's picture

Hi. I know I'm late to this conversation. But it's hard to find info on repairing a Hobart-era K5SS. Mine has been making a "grinding gear" sound that I'd like to repair. 

I can't figure out how to make the direct message option work on this site. But I would appreciate getting a copy of the service manual. You can e-mail it to cornwallw at gmail


dWolf's picture

May I please have a copy of the K5SS manual.

(I don't see the messages button in the upper left?)


thank you.

waldemar's picture

Hello - I realize that your kind offer dates back a few years, but if you (or anyone else) can send me the Hobart service manual (we have a K5SS) that would be great! It looks as if the messages component has died with one of the Drupal upgrades to this site, but I can be reached at wjkowalski _at_


breadbaker47's picture

Having same exact issue. Did replacing the gears help?