Walker Mower Blades Hit

[jonno]

I recently purchased a older walker (I believe it is a '95) MSSD 36" but it didn't have any blades on it. I put some on and they hit each other just slightly on one side of the blades only at the rear of the deck. I do have the correct shear bolts in and they are installed correctly (aprx. 65 ft lbs of torque on the center nut). There is a small amount of play in the shafts and the gearboxes were dry when I checked them. The play doesn't seem to be in the gearbox itself but it has about a 1"+/- of play at the tip of each blade causing them to hit. Is there a way to retime them so they don't hit?

[ericg]

The best thing to do is loosen one of the outboard gearboxes from the coupling and index the blades so that they are perpendicular to each other. In other words, one blade should be facing front to back and the other blade side to side. At that point, they are in time. Someone may have replaced one of the boxes and not realized that they have to be indexed.

Eric

[jonno]

Inside the outside gearboxes there are two gears with about a dozen teeth each to transfer the motion from horizontal to vertical. I am 99% sure the mower has been mowed with since the gearboxes were redone and also the amount of blade hitting is a not whole tooths worth of misalignment. The tips of the blades just BARELY clip (every 360 degrees but doesn't do it at 180 when the oposite sides of the blades are in the same position) when they pass each other at the rear of the deck. Any help would be greatly apreciated. Thanks
~Jonathan

[ericg]

Jonno, read this thread. If the blades are times properly there is no way that they can hit anywhere in the arc while they rotate.

http://www.lawnsite.com/showthread.php?t=144536

Eric

[ed2hess]

Well did you look to see if the tang on the spindles are still in place to keep the blades from turning after tighening the nut. Maybe the device to keep the blade from turning relative to the spindle is worn off.

[jonno]

I have attached 5 pictures with this showing the problem. The first shows the blades at the rear of the deck as far apart as the play allows. The next one shows the actual problem itself with the blades overlapping as much as possible. The next two show the blades at the front of the deck in both positions. The final picture shows the blades perpendicular to each other (exactly 90 degrees). If I retime them so they do not hit at the rear it seems to me they will at the front therefore I have been somewhat reluctant to go through the trouble of retiming the (besides the fact I just filled them both up with expensive EP90 gear oil). I have just recently noticed a small leak from the right gearbox (see image 5) that was previously dry. I am wondering if they gears are worn from being run dry and the play is causing them to hit. If so, will I need to replace the gearboxes?

[cantoo]

jonno, 36" deck uses 20" blades. 42" deck uses 22" blades. 48" deck uses 25" blades.
Looks to me like you have 42" deck blades on there. Check a mower blade website and make sure you have correct length. Nothing wrong with your timing by the look of the pics.

[ed2hess]

Shear pins loose on one side .....that probably means one side is slipping relative to the spindle shaft, maybe.

[SLR]

jonno, 36" deck uses 20" blades. 42" deck uses 22" blades. 48" deck uses 25" blades.
Looks to me like you have 42" deck blades on there. Check a mower blade website and make sure you have correct length. Nothing wrong with your timing by the look of the pics.

Cantoo, how on Earth can you tell these blades are 42" deck blades,tell secret please!

[ericg]

Cantoo, I just looked at three of our Walker's with 42" decks and when the blades are rotated by hand, there is never a point where the blades even come close to hitting each other. I can't tell from the pictures whether or not the blades are right for the deck but it seems to me that the timing is off and that is causing the problem.

Eric

[SLR]

JonnoWrote:"There is a small amount of play in the shafts"

Could the bearings underneath the blades or something be old/tired?

[jonno]

Cantoo: Sorry but the blades are the right ones. They have a 20" diagonal on them. Good guess though (that was my first thought too):)

Slr: I don't believe there are any bearings on a shaft driven mower like this. One of the pluses.

Ed2hess: They have brand new shear pins on them and I believe them to be installed correctly (a nut and a bolt through a hole, how hard can it be?)

Eric: There is the possibility that the gears jumped a tooth but the amount of wear on the teeth doesn't seem to warrant that happening. Either way they would still hit if I moved them over a tooth (I think worse actually).

How important is the 65 ft/lbs of torque on the nut? So long as the blades don't fall off (I don't have a torque wrench. Should I get one?) I am about ready to break down and take it in to the dealer and ask them to tell me what's wrong.
Thanks, Jonathan

[ericg]

Jonno, I have rebuilt many of the Walker gearboxes. I am not saying that the wear on the bevel gears would cause them to jump a tooth. In fact, if the gears were that worn, they would be jumping teeth all of the time since there would not be enough tooth contact to transfer the torque to turn the blades. I believe that one or more boxes might have been replaced and from that time, they were not timed properly. The Walker gear box system is very simple with no adjustments on the gears or bearings within the boxes, so they are either good or no good. If you loosen up either one of the outside boxes and separate it from the couplings, you should be able to reinstall the box and align it so that when one blade is facing front to back, the other will be facing side to side. The other thing to check, and this would be a long shot, is the couplings that attach the right and left side boxes to the center box. The spline for the coupling is a very fine spline and I am wondering if there is any issue there where the coupling is worn allowing the fine spline to shift within the coupling.

Eric

[cantoo]

I couldn't tell what size the blades were from the pics but it looked like they were hitting by quite abit and were tight to outside of deck so maybe wrong length?
Maybe the lip hub is worn off and letting the blades spin freely? They might appear to be tight but when power is applied they free spin?
Fact is the blades are hitting and from pics they are timed right only other thing it can be is the blades aren't staying in that position. So the blade cup side is worn or the spindle lip is worn.

ps, torque doesn't seem to matter much. I used to torque ours down but don't bother anymore and (gasp) I don't use the little Walker shear allen bolts either. I buy the little machine bolts and just replace them every couple of weeks. Much cheaper and very very seldom break. And I've never wrecked a gearbox in 1600 hrs either.

[ericg]

Jonno, Cantoo's point about the blade holder not staying in its correct position may be valid but that is something that is easily checked. But the fact of the matter is that if the blades are timed properly then there is no time at any point in the rotation of the blades that they should come close to hitting each other. I think that you need to step back, take a close look at the blade holders and see if there is any play when you attach them to the box and then start to revisit all of the other items that people have suggested. My point is that if the blades are timed properly with the mower off, you should be able to rotate the blades through a full rotation and never have them hit. Now if that is successful and you go out mowing and they start to hit, then something is slipping. Even with the play built into the Walker blade drive system which can be up to 1" there is still enough room for the blades not to hit. I just checked a 42" Walker deck by manually rotating the blades a full rotation and nothing even came close to hitting. Since this deck came to you without blades and you never saw it working properly, you will have to check everything to determine what the problem is.

[wallzwallz]

In the pics the 2 nuts don't look threaded all the way. Have you checked the 2 blade cups to see if there all the way up on the spindle? Are the 2 straight sides of the cups center hole rounded? How about the spindle end, is it still square on 2 sides?

[jlawnman]

jonno, 36" deck uses 20" blades. 42" deck uses 22" blades. 48" deck uses 25" blades.
Looks to me like you have 42" deck blades on there. Check a mower blade website and make sure you have correct length. Nothing wrong with your timing by the look of the pics.

I would have to agree here... these are the wrong size blades... measure 'em and let us know...

[tomo]

hi ,
Side discharge gearbox decks ARE NOT the best product walker ever produced . READ ON

On the 36,54 sd [54 uses same blades ] decks it was found that there was to much over lap . Therefore any wear in below items risks damage
1/blade adapter gold colored piece
2/ the out put shaft has 2 machined parallel flats that fit into the above adapter . I have my 42 output shafts machined every 2years or so

THE pictures of the gear boxes leaking oil is typical of blade collision . Both need a good over haul
Together with the flats on the output shafts being machined ,the area where the seal contacts will probaly be grooved [repair at the same time ]
Reset bearings with locktight bearing mount if the housings are not worn out

Critical on these decks is the blade timing ,they cannot be one spline out

Blade collision is more so encounted with after market blades [slightly different shaped at tip area ].

On the 54 and therefore the 36 i cut around 3/8 inch of each tip

Remember the 54 but now it is a 56 inch deck using the same blades .
THIS TELLS U ALOT the overlap has been reduced :hammerhead:

AT a point in time there was a swing back blade conversion EG push mower type for the 54

Flip the deck up and look in the overlap area ,on a side/ d deck the blades rotate in opposite direction
EG After the shear pins break the design promotes a head on collision of the tips therefore causing damage to gearboxes eventually

ON A GHS DECK THE BLADES SPIN IN THE SAME DIRECTION IN THE OVERLAP AREA -blade contact if it occurs causes very little damage

TOMO :waving: