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MTD Yard Machine 10HP 28" snowblower drive not engaging, machine barely moves...

23K views 28 replies 9 participants last post by  RIT333  
#1 ·
I have an MTD SnowBlower Yard Machine 10HP 28" cut. Model# 31AE5MLG729, Serial# 1I104B50399.
The auger belt and auger engages just fine. The drive system is another story. When putting it into to gear, any speed, it initially moves than stops, so I removed the under plate, looked at everything and looks normal. I removed the belt cover and found that the drive belt was a bit loose. I've been working on snowblowers for a while now and I can't recall a drive belt being loose. The auger belt being a bit loose is normal until you engage it. So the drive belt was on the upper shaft pulley and the lower pulley.
I attempted to adjust the the drive cable tighter but it didn't matter. I still ended up with the same result. The machine would move a bit when engaging the drive but then stops. Everytime I end up having to push it back into the garage.
What am I missing?? I ordered a new belt online just in case but why would the drive belt, which looks in good shape, be so loose?
All the springs on the drive plate are in tact. The rubber wheel/skid plate wheel for the drive looks ok too. Hope someone can help. Thank you.
Anthony
 
#2 · (Edited)
First, determine if it's the belt or the rubber wheel that's slipping. With the belt cover removed, see if the belt and plate are still spinning when the machine stops moving forward.

Check how well the rubber wheel presses against the plate. With the engine not running but the drive lever engaged, are you able to hold the plate steady and turn the rubber wheel by hand, making it slip? You shouldn't be able to, even with a fairly strong hand. If it's worn down or the plate has something slippery (like oil) on it, then you should clean the plate and/or replace the rubber wheel.

As for the control cable, you want to adjust its length such that at about 2/3 to 3/4 of the handle's travel the rubber wheel touches the plate, and that for the rest of the handle's travel, you're stretching the large spring that allows the handle to be go all the way.
 
#5 ·
This is great information. Very kind of you to respond so quickly. I ordered the donut skid plate disc to replace just in case. Heres the strange part, the machine starts to move a little bit as I engage the handle down, then it stops. I will have to clean the plate as recommended. I will follow up.
It might be the wrong size belt...
 
#9 ·
Ok everyone! I received my new drive belt and found it's the identical size as the one that was in there. I also came to realize that the brake rubber wheel of the drive was engaging on the plate tightly.
So, here is the problem again for those who are interested. The drive belt doesn't spin all the time when the machine is started. It seems that the belt is too long but its not. Could it be the tensioner spring or the tensioner? I'm lost and I'm usually pretty good on wrenching on these pieces of crap...
 
#10 ·
any chance the tensioner spring is shot? the belt is too loose on the machine even though i replaced it, the only thing that snugs up the tension on the drive belt is the tensioner... could the spring be fine and the pulley is bad?? im assuming the pulley is the pulley, it may be the spring...
 
#11 ·
replaced the belt, adjusted the cable, the drive belt still does not spin in neutral, meaning too loose.. loose as heck... bad tensioner? seems as though the tension spring is too long, no tension on the belt drive belt should be tight all the time as its the wheel plate and rubber wheel that makes the machine move, not the belt by itself.. correct?
 
#13 ·
My gosh! You are right on the money...
Allow me to respond- First, yes, as you described, the idler pulley is mounted to the motor, the pulley spring hooks to the bottom of the pulley housing, other end of the spring connects to a bolt threaded into the motor on the other side of the shaft. And yes to the belt number, that's what I purchased..
Now as far as the 2 piece pulley for the drive belt, it does split in two as your photo shows... but I'm confused on your instructions to spin the PTO(not sure what PTO stands for) sheave after leaving pressure on the belt... is this the lower, under the machine aluminum wheel that the drive belt hooks up to or the upper drive pulley? Is the key replaceable...?
I have done several shear key replacements on lawnmowers, is this what might be the problem? Again, I appreciate your assistance.. I'm getting closer to figuring this out... Well looks like I bought a brand new belt for nothing but thats ok. I did make one more mistake I will share... I thought by shortening the tension spring it would put the necessary pressure needed on the belt to engage... I used needle nose cutters and spread the spring out and shortened it... oh well, Ill have to purchase another spring.. part number MTD OEM 932-0710.. I'll wait to hear back! Thx Brother!
Anthony
 
#14 · (Edited)
if/when u put it in drive see what the engine pulley is doing, if under load(in drive) and motor pulley stops turning but engine shaft is still turning then looks like a sheared key in the engine pulley, and yes it would cause same problem as in a lawn mower key broken.
correct me if i'm wrong, pto sheave aka main engine drive pulley, the one w/a possible broken key
 
#15 · (Edited)
i would remove the spark plug wire, cable tie the drive handle down remove the belt cover, stand it on its nose, remove the pan , turn the tires to see where the slippage is happening. and its odd that the wheels arent pinned on the axle? pics?
 
#16 ·
So I just removed both halves of the drive pulley... both key areas in each half are in tact. I attempted to spin the split pulley on the shaft and it catches the slit in the motor shaft... Im confused on where the shear key is located for the engine pulley? do you mean the drive pulley? sorry, confused on where to look.. thx!
 
#17 ·
I did try this... I clamped the drive handle to engage the drive, tipped the machine and tried to move the wheels, the wheels dont move, the rubber donut friction drive wheel locks down on the drive plate tight..theres nothing wrong with that part... the drive belt does not get tight, i purchased a new drive belt but it was identical to the old one... I cant figure this out..
the wheels are not pinned on the axle, they are bolted on.... each side has. at the hand bars, a lever to pull for traction on one side or the other..hard to explain what that is..
 
#18 · (Edited)
k, engine on, lever for drive tied down, belt cover off, belly pan removed.
you should see drive pulley turning visible either from belly pan area or from top of machine under drive pulley depending on machine.
idler pulley for drive pulley turning.
rubber friction wheel turning.
drive disk wheel turning, the flat disk where the rubber friction wheel makes contact to.

warning: if all these are turning then the wheels must also be turning "unless" you have a broken chain and or sprocket/gear going to/attached to the wheel shaft
u can make vid of all these points for us to see
 
#21 · (Edited)
so the belt is slipping at all the points of its travel? slipping only on the large drive pulley, the one attached to drive friction disc? slipping on the engine pulley?

ive heard of a bad pulley where the "v" in the pulley was too worn out so the belt would not grip the sides of the "v" in the pulley especially if under load no matter how tight the belt was

edit. u could spray into the "v" of the bad pulley w/what football players use to help catch the ball, stickum iirc to test it out, might only work for a minute or 2 if at all
 
#20 ·
i can make a video, I understand if my description is not clear. The machine moves for a second, than stops moving, it tries to move but the drive belt is too loose, it supposed to be spinning on the the drive pulley at the shaft where the auger pulley is, but it doesnt, even being on the drive belt tensioner properly, the belt should be on tight, when starting the machine the drive pulley is not spinning the drive belt as it should meaning there is an issue somewhere with the belt, the belt drive pulley or the drive wheel below under the belly pan...
 
#22 ·
I will make a video and share. The drive belt, when installed, with the motor off, should be tight. The auger belt will not be as tight as if it was the auger blades would always spin and cause potential injury.
When I install the drive belt, the tensioner and belt in the correct position, the belt is not tight at all. That is the whole problem.
The split pulley has both metal tips in tact which slides into the engine shaft no problem. It's looks to me that the tensioner is not doing anything to tighten the belt. Again, even though the belt is hooked around the lower drive disc and hooped around the upper drive pulley and around the tensioner, WHEN STARTING THE ENGINE, the drive pulley spins but the belt does not spin because it's too loose
 
#24 · (Edited)
spring in idler pulley is weak or not installed correctly.
or pivot point for bracket holding idler pulley needs lube or is binding on something.
or try a belt 1 inch shorter, goto auto parts store, bring belt w/you, ask them to measure and buy an indrustrial or farm vbelt thats 1inch shorter, not automotive vbelts.
 
#27 ·
Jan 2019 - I was having the exact same problem with my MTD Yard Machines Snow Blower. Drive belt good, seated correctly, friction rubber wheel making solid contact with drive flywheel. When i would engage the drive, the blower would move an inch then stop - just as you had described above.

I discovered the issue and came up with a solution. The problem was the drive idler pulley. The hole in the idler arm in which the idler pulley bolt screwed in was stripped, thus the bolt was not holding the idler pulley well, thus no real tension on the drive belt. Lucky for me I had a bolt the same diameter, only slightly longer. I disassembled the idler arm from the engine, ran the bolt through the back of the idler arm (through the stripped hole) and used two nuts to secure the pulley to the idler arm. Then re-assembled the whole assembly, and hooked the spring back over its bolt to add tension. Now the drive belt was spinning properly when the motor was on, and the snowblower now moves in all 5 gears and the 2 reverse. Great because its snowing outside right now - need it for the morning!!!!!