Model YTH 18542 Mandrel Assembly

[oldntired55]

I've had this riding mower since 2019 and after this much use I'm anticipating replacing them even
though at this point they seem to be doing ok. From past experiences I never get more than five years
out of a Mandrel assembly. So on my last sears mower I replaced those mandrels with ones that had
grease fittings which worked real well. But---now I see from doing internet searches, all the mandrel
assemblies available for my mower are grease-less?

Could somebody please explain how these new mandrels work without grease? and is it a waste to
look for an assembly with grease fittings these days? Thanks Bob

i disassemble the mandrels, wash out any dirt grease etc, then i drill and tap for 1/4 x 28 grease fitting. clean the chips out... THEN, remove the seals from bearings that face toward inside of mandrel. rinse the bearings out, then re-assemble. i also drill a 1/16 weep hole at the top of mandrel, just below upper brg. this lets you know when the grease is up there, BEFORE you blow the remaining seals out . when you're finished greasing, put a #8 self drilling screw in the hole. that will keep the water out and grease in. before anyone doubts my process...i did this to my 30 yr old Craftsman mower 12 yrs ago... SAME spindles today.i grease mine twice a season. sealed bearings are a joke in this application, you will see what i mean when you pop those seals. if the bearings spin free after you remove the old dried out grease.. re use them!!

 

[RevB]

I've had this riding mower since 2019 and after this much use I'm anticipating replacing them even
though at this point they seem to be doing ok. From past experiences I never get more than five years
out of a Mandrel assembly. So on my last sears mower I replaced those mandrels with ones that had
grease fittings which worked real well. But---now I see from doing internet searches, all the mandrel
assemblies available for my mower are grease-less?

Could somebody please explain how these new mandrels work without grease? and is it a waste to
look for an assembly with grease fittings these days? Thanks Bob

I've had this riding mower since 2019 and after this much use I'm anticipating replacing them even
though at this point they seem to be doing ok. From past experiences I never get more than five years
out of a Mandrel assembly. So on my last sears mower I replaced those mandrels with ones that had
grease fittings which worked real well. But---now I see from doing internet searches, all the mandrel
assemblies available for my mower are grease-less?

Could somebody please explain how these new mandrels work without grease? and is it a waste to
look for an assembly with grease fittings these days? Thanks Bob

This damn forum software sucks....what damn site DOESN'T take jpeg files. And for mobile devices....halt, stop, freeze, tries to correct your spelling.......y'all should bitch hard at this site's owners.....but good luck finding them.

Rant done. Get a set of grease needles off Amazon. In most cases you won't need to remove the spindle to slip the needle under the seal edge, or straight through if desired, and give the bearing a couple of shots.... don't over grease as too much will cause balls to skid, not roll as they should

 

[StarTech]

Well you can also blame your mobile devices for saving in the largest file they can. And forum site only has has so much storage capacity.

I recently was given a Smart phone that every image takes up a lot memory with unnecessary reduntant data. Personally I still use the old VGA pixel format of 640 x 480 for images. And for this site I use a 1000 x 1000 max format.

 

[tgzzzz]

So, bearings don't come with much grease ..........and that's OK. Kinda hard thing to relearn. I have back up spindles without Zerks. Think I'll jsut leave them as is.

 

[StarTech]

And after market bearings comes packed with lousy grease too. This is why I repack them here before I install them with EP2 wheel bearing grease.

 

[TobyU]

Some people on internet claim the grease still gets into bearings despite being sealed. I know in some cases it takes up to 150 pumps on these spindles before grease comes out to let you know it is full. Others claim at a minimum it helps keep moisture out. It has bothered me for a long time, and wish I could get a definitive answer.

People say a lot of inaccurate crap on the internet. I have taken these bearings out myself and have yet to find one that was open on the inside. They are the most common and cheapest bearings out there with the little rubber press and seal on each side which is designed to keep everything out so no grease is getting in there.

 

[TobyU]

I've had this riding mower since 2019 and after this much use I'm anticipating replacing them even
though at this point they seem to be doing ok. From past experiences I never get more than five years
out of a Mandrel assembly. So on my last sears mower I replaced those mandrels with ones that had
grease fittings which worked real well. But---now I see from doing internet searches, all the mandrel
assemblies available for my mower are grease-less?

Could somebody please explain how these new mandrels work without grease? and is it a waste to
look for an assembly with grease fittings these days? Thanks Bob

It's not worth messing within all the news pretty low quality bearings today. Just don't buy the brand name spindles and buy them online where you can get them super cheaply.
The last ones I ordered we're between 9 and 12 dollars a piece shipped to my house. I do always buy the ones that come with the screws too so I don't have to go to the hardware store because you almost always snap off some of the bolts. At these prices if you get over 3 years out of them it's well worth doing again.
Also, if you're not doing that long out of them, keep water away from machine and never use that deck Port wash clean out.

 

[bertsmobile1]

RS is the designation for radial seal, which is a rubber seal and seals water/grease/dirt out (up to the point where pressure, vacuum, wear, or some other force causes the seal to fail). 2RS designates that there is one on both sides of the bearing. ZZ metal shields are not necessarily water/grease/fine dirt tight, but do keep the bigger stuff out.

I work in manufacturing, we also do some assembly. One of those assemblies calls for a 1RS bearing. The seal gets assembled on the environment (water/dirt) side, the 'no seal' side towards the grease fitting. The 1RS bearing is a special, the 2RS is readily available. We buy the 2RS bearing, pop 1 of the rubber seals out with a screwdriver or pick, and we're good to go. The 'no seal' side allows the grease to enter from the grease fitting, the seal keeps the environment stuff out and allows pressurized grease out.

I don't work in the mower world and am curious, do those of you who do work on them daily see more spindle bearing failures on the decks that have those garden hose ports built into them and used all the time?

You have that backwards
Pull a seal out and have a good look at the direction of the lip
It keeps the grease in not water out

And yes the water sits on top of the hot bearing then gets sucked in as it cools
Replaced so many of them it is not funny and for some reason Cubs seem to be the worst .
Never let water near then deck, use air, grass responds better to air than water .

 

[bertsmobile1]

OK Thanks, I might just try doing the bearing change out when the time comes and use this thread as a
reference. Other question I have is from past experience in removing the mounting bolts that hold the Mandrel
assembly in place usually break off when you try to remove them! For the normal hack mechanic
like me, that pretty much renderers the housings un-useable

I guess pre-treating the treads with penetrating oil might help that

penetrating oil is of little use
The self tapping threads have very sharp edges that raise stresses so initiate a failure
They are also induction hardened and that makes them even more prone to cracking .
The bolt is steel the mandrel is aluminium so you get galvanic corrosion if the two metals are in intimate contact and the whole thing gets damp and for that just dew is enough.
THe aluminium oxide Al203 is about 4 times the volume of the aluminium before it corroded so it locks the thread in really tight
The mechanical shape of the self tapping thread means it is very strong when being screwed in but a lot weaker when being undone so usually ay least 1 of the bolts will break or a lug snap off completely so never touch the mandrel bolts unless you are going to replace the whole shooting match .
This is why I suggested precutting the thread and applying anti seize ( not grease ) to the bolts .

 

[platefire]

So that is why it's being recommended just to pull the deck and change the
bearings in place-------saves dealing with a broken Mandrel bolt or having to
replace the whole Mandrel assmebly?