50 inch Deck Idler Pulley Bearings

   / 50 inch Deck Idler Pulley Bearings #1  

mowcub

Member
Joined
Aug 23, 2011
Messages
38
Location
Piedmont, SC
Tractor
Cub Cadet GT2550
I have a GT2550. Anyone else experienced bearing failure on the double sheave idler pulley? I began hearing a high pitch whine last season even though I had greased all the pulleys, I gave them another shot and it changed the sound a bit so I knew it was a bearing. I could not tell which pulley. So over the winter I dropped the deck and removed the belt. It was easy to tell which one was the problem once I could spin them by hand. So the idler pulley has two bearings that are only sealed on the outer face. The open side is supposed to be fed grease by one nipple in the center of the pulley shaft which is hollow between the bearings. Well I think the grease tends go to the bottom bearing and does not get forced to the top. The top bearing was bad. The bottom wasn't far behind as it had some rough spots as well. The bearings are not pressed in. In fact they fit rather loose in the pulley. Not a big problem unless they bind and start to turn in the pulley. Mine showed no signs of that. So the bearings are a 40mm OD for a 5/8" shaft and 12mm wide. I bought two sealed bearings as a replacement and installed them. So far, it is the quietest my deck has ran since new. Hopefully they will hold up and not overheat. The other idler pulley has a sealed bearing. Any thoughts? BTW the MTD OEM bearings are about $15 each and I bought 2 sealed ones for a total of $7.24. They are identical in size and also made in China. I might find a better quality one if they work OK.
 
   / 50 inch Deck Idler Pulley Bearings #2  
Sorta sounds like mebbe that brg was damaged and dry from the getgo.. but perhaps when that zerk is pumped full of grease the top brg will get some of the lube...? Anyhow, good that you are up there in the peidmont and not down in the midlands or lowcountry where all that sand is about... brgs don't much like sand.
 
   / 50 inch Deck Idler Pulley Bearings #3  
I got a little over 500hrs on our 50" deck and have replaced every deck bearing possible. meh...it is what it is.

I admit to working the deck harder than the next 10 guys here. Not that I don't pull near religious like maintenance ...I do. But I made a lot of mods to cut a real short fairway type cut...and I cut wet grass as well.

Got to say I'm really happy with this mower now...just wish I could have bought it this way.
 
   / 50 inch Deck Idler Pulley Bearings
  • Thread Starter
#4  
I've been real pleased with the mower so far. This will be my 4th season. It still has the original belts, but I have a set on hand for this season. I put risers under the belt covers this winter so it will be easier to blow the grass out from under them. Other than a battery, everything else is original. I was disappointed to see that the bearings were made in China. I will be looking for higher quality replacements if the spindle bearings start to go. The cost of good bearings might save MTD some bad PR because if you don't service them regularly, they will go dry and quickly fail.
 
   / 50 inch Deck Idler Pulley Bearings #5  
What mods did you make to cut shorter ? I want a shorter lawn than what this will do now. I was thinking of asking a machine shop to make longer spindles and add spacers to lower blades.
 
   / 50 inch Deck Idler Pulley Bearings #6  
bluefin,

Over time I carefully, gradually and equally lowered tire pressure after starting from a known pressure.

Then I added washers between the blades and spindles...and used red lock tight. Also took off the guide wheels and cut off the guide wheel brackets where they hung below the deck.

Cobbled up a 'bale' to flip over and hold down the deck adjusting knob...in that way I could tweak the 2 deck springs so the deck would float and stay where-ever I put it. Now the deck will raise automatically when inclined by mowing conditions to do so.

Because of the washer tweak and the blades hanging lower I save beaucoup time by sharpening them right on the deck with an angle grinder. Boy do I love that move, yeah it's way less perfect than the way I use to bench grind but the blades are of such a low quality now that they don't deserve that extra time spent anyway.
 
   / 50 inch Deck Idler Pulley Bearings #7  
By idler pulleys do you mean the spindle bearings , as the 2 idler pulleys I refer to one is solid mount the other spring tension mounted , well one chopped out the other week and second one was so gravelly that I replaced it as well
GT 2550 were available new in Australia up until last year so mine is still under warranty , dealer gave me both pulleys and I installed.
With the old ones you can drill out the pressings 1/4" and press out old bearing , put in a new one and clamp back together with 1/4" bolts and nylock nuts.
The reconditioned ones are better than the new genuine part
These pulleys must have been on a recall as dealer replaced them no worries , no arguments.
With regard to cutting close the first thing I noticed is that with the anti scalping wheels at the highest mounting point you could not get the deck all the way down , so I made a template of the holes and used it to drill and additional hole higher up on the bracket , this has partially solve the problem but next time I have the deck off I will put a small spacer in to lower the blades down the spindle a bit more , this should give a slightly closer shave.
One tip in putting deck back on is to sit it on 1/2" pieces of wood at each corner anti scalping wheel and you will find it much easier to connect the back 2 hangers
 
   / 50 inch Deck Idler Pulley Bearings
  • Thread Starter
#8  
By idler pulleys do you mean the spindle bearings , as the 2 idler pulleys I refer to one is solid mount the other spring tension mounted , well one chopped out the other week and second one was so gravelly that I replaced it as well

I am referring to the idler pulleys. Specifically the one that is mounted with the spring tensioner. It is a double pulley. The two bearings were not a tight press fit. I replaced them both with sealed bearings. So far the other one is still OK.

My deck cuts at 2" which is plenty low enough for my grass. My ground is not smooth enough to cut any lower.
 
   / 50 inch Deck Idler Pulley Bearings #9  
Our decks must be a bit different as I have that dual pulley , belt from motor and deck belt plus 2 other idler pulleys these are the ones that had dodgy bearings
 
   / 50 inch Deck Idler Pulley Bearings #10  
^yeah our 50" deck has the double pulley centered near the back of the deck. The top pulley gets drive from the PTO and the bottom pulley connects and drives the blades.

I took the idler pulley to mean the springed tensioner pulley...and yeah I replaced that too.
 
 
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