Kitchen Aid mixer shaft - fell apart

[SteveH-CO]

Got this from a buddy. Kitchen Aid 6.0 quart pro model. The splined shaft is pressed into the casting, and it simply fell apart during use. When I attempted to reinsert the shaft into the casting, it had a lot of resistance. I'm tempted to clean it well, apply sleeve retainer, and just press it back together and assume it will hold. I also considered drilling through the casting and shaft (which is surely hardened) and installing a roll pin. Any other approaches I should consider? A set-screw through the casting? This shaft/casting interface mostly sees lateral loading and minimal tension. The last photo shows that the casting hole is blind. Thanks!

 

[240sxguy]

You could see what a new one would cost, I was pretty surprised at how reasonable the parts were when I rebuilt the one I got with stripped head gears.

 

[SteveH-CO]

Thanks! I rarely give new parts enough thought.

The new part is $50-70 (and you have to get the right color), but this is Garage Journal, so I'm trying to be cheap and fix it myself ;-)

 

[nadogail]

My opinion is; study all your options before planning a course of action.

 

[240sxguy]

Thanks! I rarely give new parts enough thought.

The new part is $50-70 (and you have to get the right color), but this is Garage Journal, so I'm trying to be cheap and fix it myself ;-)

As least you know you're only in for $50-70 if your repair doesn't go as planned. Not that I'd know anything about that. lol

 

[RPH]

Used to work for Hobart on the big machines. Rarely would we see the kitchen aid line. Can you drill through the casting and into the end of the shaft. Use a bolt to attach it. Also use food grade grease for lube. Whatever lube you use, you will be eating it!

 

[My Old Tools]

I would press it in with some Loctite bearing retainer and see what happens. You can always drill it later. If have a lathe, you could knurl that shaft to get more bite.

 

[rlitman]

Before you go fix it and have the machine die soon after, what material is the gearbox cover made from? If it's one of the notorious (especially on that model) plastic gearboxes, go and replace it with a cast metal one. You may be able to save the grease if it's still in good shape. Also, if this is a bowl lift, make sure the three head to base screws are tight, and consider adding some loctite to them.

 

[SteveH-CO]

Thanks. Good suggestions. I bought a 1/8" roll pin (tension pin) at Ace for .33, so I may resort to that, as well.

I have seen the head-to-base screws work loose (on my wife's well-used machine). The plastic gearbox cover has not yet cracked, but a YouTube video pointed that out as a weak spot. Looks like the metal gearbox cover is fairly expensive, so I may just wait until it cracks.

RPH >> Can you drill through the casting and into the end of the shaft. Use a bolt to attach it.

I thought of this - might be easier than drilling cross-ways through that thin casting.

 

[rlitman]

... The plastic gearbox cover has not yet cracked, but a YouTube video pointed that out as a weak spot. Looks like the metal gearbox cover is fairly expensive, so I may just wait until it cracks...

The $36 gearbox top is cheaper than a replacement gear set that you'll need after it cracks (plus the grease).

 

[matt_i]

My suggestion would be to drill a thru hole in the casting on its center up into the recess, then drill & tap the shaft end for something like #8 to #10 screw and use a button head stainless steel internal-torx drive screw to fasten them together.

It appears the spline is working for "tractive drive" unless you can see the internal splines are wiped off. The cross-pin (spring-tension rolled pin) is reasonable at first but you have to have a long skinny drill go down next to the flange and not push off the OD as its trying to pilot into the OD. Much more easily done with something like a spot drill but that requires a close-grip on the drill bit and there's no clearance for the chuck. But to get a cross-pin to work correctly, the holes have to be aligned when its assembled and the easiest way is to put them all on center with fixturing in a machine tool like a knee mill. I've seen poorly executed holes which wander and require the pin to bend its way thru but something eventually gets destroyed from excessive force: the end of the pin or the fragile OD of the hub could easily let loose. With the on-center screw to simply retain the spline-drive all of these issues go away.

 

[SteveH-CO]

I ended up using sleeve retainer (Loctite) on the shaft. Reassembled and it seems to sound and work as it should. I will have my wife make some bread, which puts a heavy load on the mixer, and see how it holds up. If it passes that test, I'll consider beefing up the repair and/or the metal gearbox upgrade.

I thought of all the issues that @matt_l mentioned and he's right. If it doesn't survive my repair, I'll do what he suggests. @rlitman - thanks for the link to the metal gearbox cover - I hadn't found one nearly that cheap.

 

[rlitman]

I'm betting that your repair will hold, but if not, I wouldn't go drilling it. Too much risk of something falling into your food.
Because this sits under everything and faces the stainless bowl, I think a chrome one wouldn't look terrible (as opposed to needing to get white):

Pardon Our Interruption...

I'm not 100% positive that's the right one for you though...

Or here's a black one that's even cheaper:

WP9708176, Black Planetary Assembly fits Whirlpool KitchenAid Stand Mixer | eBay

New, WP9708176, Black Planetary Assembly fits Whirlpool KitchenAid Stand Mixer.

www.ebay.com

I do agree not to throw money into a gearbox before you know the rest of the machine works.

 

[SteveH-CO]

Those are great prices on that assembly. A great 'plan b' if this doesn't hold. Thanks!

 

[jimy]

If the label says made by Hobart it would be great to fix it. The newer ones - not so much.

 

[trs71]

I've got about the same model.

It's supposed to be the best you can buy, for home use. It's powerful, but if you overload it or wear and tear, that's the weak point.

Sadly like almost all items today, everything's cheap plastic. not even regular plastic.

 

[SteveH-CO]

My fix with sleeve retainer compound survived my wife's bread making. She runs the mixer on speed 4 with the dough hook, rather then 2, as suggested by Kitchen Aid. It puts the hurt on the mixer, and it passed with flying colors. I'm declaring it fixed. May upgrade to the metal gearbox if I'm feeling sporting.

 

[jacked_72]

What timeliness! I just picked up one of these mixers last night for $25 with the same problem! Based on what I see on the internet, it is a common, common issue. What a terrible design. That rod is supposedly pressed in, but it can't be much of a friction fit. I red locktited mine back on last night and it seems to be holding -- the weight of the attachment didn't cause it to fall off like before. I've ordered a replacement part, but it will certainly fail too. I'm thinking that drilling and running a roll pin or a SS bolt with a nylock nut on it is the way to go. There should be plenty of room. The only issue is getting a straight enough shot at drilling the hole.

 

[jacked_72]

Here's what I did to the shaft and planetary last night. I couldn't find the right size pin or stainless bolt, so I used a regular bolt, double nutted it and red locktited it. I don't think its falling off again in my lifetime. I think a cotter pin or even a bent nail would have sufficed. I would like to have drilled it closer to the bottom, but there wasn't enough clearance for my drill press. Nothing is hardened, so this was an easy fix. I do think the red locktite would have been fine for many years, but it would take a lot of this to fall off now.