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lanshark12

craftsman blades randomly engaging

lanshark12
9 years ago

craftsman 42"
model 917.255440
new belt

engaging the blades does not usually engage the blades, there is no difference when moving the blade engage handle. but after running a while (random length of time) you can hear the blades smoothly engage. blades will continue to engage and disengage randomly.

any steps to troubleshoot?

Comments (20)

  • tomplum
    9 years ago

    Is the new belt a 130969? You could be dealing with a few different things here. There is an adjustment in the linkage off the main deck lever to help you get the correct tension. The idler cam on the top of the deck must pivot freely. You could also have a broken spindle leg which allows the spindle to pull with the belt, so it won't keep tension. Sometimes the top plate of the deck will come loose (welds pull through) making it impossible to hold tension on the belt. A few things to get you started.

  • lanshark12
    Original Author
    9 years ago

    the belt i have is the 130969

    thanks for the suggestions, i'll go check them out.

  • lanshark12
    Original Author
    9 years ago

    i couldn't find an adjustment in the linkage, although i did find where the engage rod tied into the deck there was an additional hole in a different (further away i believe) position.

    i also found that the star portion of the spindle was completely gone, so i will start with replacing that.

  • lanshark12
    Original Author
    9 years ago

    could anyone help explain exactly where this adjustment is, or should be? this is an adjustment attached to the linkage for the blade engage correct? helps tighten the belt?

    i replaced the spindle and now the blades barely run at all, the pulley atop the other spindle seems to wobble a bit so im guessing thats a bearing and should be replaced, even so i'm thinking the belt is too loose?

  • lanshark12
    Original Author
    9 years ago

    ok my apologies, i just had the opportunity to check out a friends mower and it appears the adjustment is at the "beginning" or towards the lever side, the rod is threaded, but mine is not

  • tomplum
    9 years ago

    Yes, usually the rod off the lever is threaded. Typically the lever will begin to engage the deck about 3/4 the way up or near the ignition switch. BTW, 142655 is the part number for the adjustable rod assy that fits your deck should you wish to install one. Thoughts would be that there must be other issues as the new belt should be able to have tension to run. Sometimes these spindle pulleys do wobble some, which can accelerate belt wear- but in itself doesn't affect tension. The center of the pulley is splined and locks to the shaft, so if its spun and slightly loose, that blade will not have enough toque behind it. does your new spindle turn freely?

  • lanshark12
    Original Author
    9 years ago

    there is slight resistance on one of the spindles, is this the bearings on the spindle?

    the bearing at the top of the mandrel seems pretty set in there, do i just need to strong arm it out? any fear of breaking the mandrel?

  • tomplum
    9 years ago

    If there is enough resistance that may have an effect on the belt, do the following. Inspect the 3 legs of the spindle and if they seem solid- not cracked, it is time to go further. Leaving the spindle installed in the deck, loosen the 7/8" nut so it is flush w/ the shaft and give it a whack with a sturdy hammer using a block of wood to protect the shaft end. Then the nut, pulley and washer can be removed. The shaft should drive out the bottom is the end result. From there you can inspect the bearings. Usually the lower will fail first.

  • lanshark12
    Original Author
    9 years ago

    ok in total the new parts are
    the adjustable rod assembly
    new belts
    2 spindle pulleys
    1 mandrel
    2 spindles (and bearings)
    2 blades.

    at first things looked good but now blades are still randomly engaging. i haven't checked the pulley attached to the engine and i haven't adjusted the belt tension. is there a method to set the correct tension?

  • tomplum
    9 years ago

    Did you check the top plate of the deck? They typically break loose from the rear weld area. The engine pulley does wear some and some times even break- so that is worth an inspection. If all seems good, I'd probably put the new adjustable rod link on.

  • lanshark12
    Original Author
    9 years ago

    i checked the top plate of the deck and it looks good. the new adjustable rod link is on and i attempted to adjust it as the belt appears to have a decent amount of slack (~1" of play[?] when engaged) but extending the rod as far as possible doesn't do much for the belt tension.

    it might be not that the blades aren't engaged, but not engaged fully, such as quarter / half speed. also it appears that a hard left hand turn nearly always makes the blades engage fully believe it or not ...

  • tomplum
    9 years ago

    I think that you are at the crossroads of rechecking some things or having it professionally inspected. I suggested inspecting the top plate where it is welded to the deck. Unless you are watching the plate lift once the deck is engaged or physically pull the deck, it will look normal. Something is obviously just wrong part wise or for some reason you cannot build tension on the belt. You had stated that you had replaced 1 mandrel & 2 spindles (and bearings) . What are you referring to as a mandrel as they are really a spindle - and your deck has 2- but somehow 3 were installed?

  • lanshark12
    Original Author
    9 years ago

    apologies for the mandrel / spindle ignorance. I guess I meant to say that i replaced 1 mandrel housing (part #128774) I replaced one of these mandrel housings including spindle and bearings on one side then one spindle and bearings (but not mandrel housing) on the other side.

    could you provide additional description of exactly where the top plate culprit would be to confirm i am inspecting it correctly? I will try it when the deck is engaged and pull the deck again to recheck.

    i appreciate the help!

  • tomplum
    9 years ago

    On the top of the deck, you have a flat plate that the upper part has the mid mount stud where the deck lift hooks to. On that same plate, the idler cam bolts to. At the rear of that plate is a single weld. That weld is what normally pulls through the deck. When tension is put on the belt, the plate will pull up in the rear so the belt remains loose.

  • lanshark12
    Original Author
    9 years ago

    i can squeeze the belt together right up against the front engine pulley, that's how much slack there is with the blades engaged. am i correct in thinking this is too much slack?

    it appears that the spring on the arm assembly spring was too tight not allowing it to move forward, therefore not allowing the idler pulley to move backwards in its full range of motion which would then put more tension on the belt.

    after loosening the spring the pulley the tension on the belt doesnt increase much. this is with the blades engaged and the engagement arm set to put maximum tension on the belt

    mower deck picture attached, maybe i am missing something?

    This post was edited by lanshark12 on Fri, Aug 8, 14 at 18:30

  • tomplum
    9 years ago

    That is an oldie! If this is a 42, it is an early version. Yes, you need less slack, plus that mechanism needs to pivot freely. Those springs do seem heavy too. The idler cam will develop wear spots at the point the brake arm rollers contact which will interfere w/ operation. Hence, the rollers must work freely too. Temporarily unhook the brake springs and see if you then can get tension. If so, back to the idler cam and rollers. BTW, your new adjustable rod will set the belt tension greater if the rod adjustment is turned towards the front end of the rod. By the pic, you have lots more adjustment you can do.

  • lanshark12
    Original Author
    9 years ago

    so to back up just a bit, that adjustable arm was previously adjusted all the way out to the nut, leaving approximately 1" of thread. when lifting the lever to engage the blades tension started about half way up, after that it was no longer moving the linkage down below, just building further tension.

    also you hit it with the roller, it moved freely on the bolt but when it hit against the metal it was supposed to roll on it did cause tension and sticking.

    now to confirm with you as i just reconfirmed with myself; if i adjust the engagement arm out towards the front (to push the pulley far into the belt) the slack (mentioned in the previous post) still exists. with the arm attached, if i attempt to push the pulley further back into the belt there is no additional movement allowed. also if i remove that adjustable arm and try to manually move the pulley the stack still exists. both of these attempts involve constant checking and movement of the arm assembly to ensure that everything was in place.

    im trying to think this thing through, whatever the answer is im sure its simple, although apparently i am more so. it appears all welds and bolts are solid and nothing looks like it has been moved (welds / bolts). im thinking any of the pulleys could be just a bit smaller than they should be, therefore creating slack? maybe with the new adjustable arm i made it so tight it stretched the belt while there was another problem that has since been fixed leaving the problem to the new belt being stretched?

    im thinking the problem lies after (towards the deck) the adjustable arm. if i cant get the idler pulley to move further back (to create more tension) then ...

    additional thanks for staying with me.

  • tomplum
    9 years ago

    Typically the PTO lever will start to tighten the belt when the lever is at the ignition switch level or around 3/4 of the way up. I'm having some difficulty following along. Some of these decks also used the 144200 belt. Though it wouldn't be the first time that the decal and IPL was wrong. That belt is substantially shorter- like 3.5 inches than the 169 belt. My cheat sheet shows the 969 belt at 92" and the 200 belt at 88.5". I see that you installed new blades, and that they were for sure for 42" rather than 38"? Was the deck ever changed on this tractor? Sans bringing the tractor in to someone familiar with these, you may just have to cheat on the belt size.

  • lanshark12
    Original Author
    9 years ago

    summer had got me all tied up, heres an update.

    i had the 969 belt which i thought was 92.5. i went for a napa belt at 92 and it seemed to do good for a while.

    i put new mulching blades on, 42". they did good for a while too. now it seems as if there is too little power for some reason and the blades seem to slow considerably if there is any grass to cut, very much like the original problem only if my speed is set to 1 (slow as possible) it runs fine. or if i drive a bit, then stop, they will speed up. I am guessing this is because the grass is cut and the blades dont have to push through the grass and spin freely?

    not sure if the deck was ever changed on the tractor.

    don't think i can get much shorter on the belt length as the 92" seemed somewhat snug.

  • tomplum
    9 years ago

    This might be one of those things that someone with experience will need to look at. My best guess is something is being missed. At this point, the belt tension seems to be getting closer to what it should be in your estimation? Or is the tension looking good, but there is another difficulty? You should be a ble to back the adjuster off in order to accommodate a shorter belt if you need to. In looking at the OEP belt by length chart, they reference belts which are 91.5" (They showed the 969 belt at 92.25 BTW) One belt is their part number 15-026 which is a Cub Cadet/ MTD 954-04142. You may be able to pick one up locally. Stens 265-222 is also a cross for that belt. Stens belts are generally pretty decent.

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