Loose driveline set screw B2782B snowblower

[nbryan]

While hooking up the front snowblower driveline yesterday the front female section slipped off the reduction box shaft into my hand, with the 1/4" key landing on the floor.
Hmmm.
It seems that the allen socket set screw for the key simply let the key go and it slid right off. It's a very good thing this happened NOT while operating it under load at 2500 rpm.
The key has a set screw scar or dimple like it should, so the screw was initially tightened ok new at the factory. It took a lot of torque to back the set screw out so I back and forth loosened it up to ensure sufficient play for tightening again. Also cleaned up a few small ridges on the key and in the key slots. Put it back together and its good and tight now.

So everyone running a B2782A or B2782B blower:

CHECK THE FEMALE DRIVELINE HEX SET SCREW AT THE REDUCTION BOX SHAFT FOR TIGHTNESS!!

I am thinking there may have been dirt or something in the key slot when the yoke was initially installed, allowing the screw to set but come loose as the dirt inclusion wore down or away?

So check your front shaft where it attaches to the blower, folks! It's not maintenance manual item, but I'll be tugging a bit at that shaft every hookup from now on!

 

[Rcflyer330]

Check your manual again I am pretty sure it says to check all screws and bolts. Actually its on page 9 #13 check all nuts and bolts periodically for tightness. Any way i am going to check mine tomorrow thanks for the heads up.

 

[kubotasam]

Are you sure that the yoke and shaft are not cross drilled for a 1/4" bolt? It is that way on my B2781. It has the set screw that lands on the key plus the 1/4" bolt through to keep the yoke on the shaft. The cross bolt shows on the parts diagram on the B2782 just like mine.

 

[Berry]

Are you sure that the yoke and shaft are not cross drilled for a 1/4" bolt? It is that way on my B2781. It has the set screw that lands on the key plus the 1/4" bolt through to keep the yoke on the shaft. The cross bolt shows on the parts diagram on the B2782 just like mine. View attachment 54398

I agree with kubotasam, my front loader also has the hole for the 1/4 bolt for locking the shaft. With set screws, I have always checked the female threads as rust can can build up at the bottom to a point you can tighten up your set screw and it may not bottom out onto the key. I suggest you run a tap through your yoke to clean threads. Never re use set screws as the teeth on the bottom of the screw wear off. I also suggest Orange lock Tight, a great product. I recommend loctite on all bolts of the front end mount snowblower to accommodate any vibrations.

 

[GreensvilleJay]

if the tapped hole is deep enough, you can add a 2nd setcrew to 'lock' the 1st one......

 

[Berry]

if the tapped hole is deep enough, you can add a 2nd setcrew to 'lock' the 1st one......

That's absolutely true, in this case it is not te ate screw on mine is almost flush.

 

[Toyboy]

Clean out the thread's with brake cleaner and use some BLUE loctite on it.

 

[GreensvilleJay]

If you don't have any locktite, use your wife's nailpolish....

 

[North Idaho Wolfman]

Like Kubotasam pointed out you are missing the bolt and nut that holds the drive line on!
That little set screw is to hold the Allen key and or to remove slight slop in the fitting, not hold the shaft on.
It's a grade 5 fine thread bolt and self locking nut.
Everyone of those models are the same, B2781A/B and the B2782A/B.

 

[nbryan]

Like Kubotasam pointed out you are missing the bolt and nut that holds the drive line on!
That little set screw is to hold the Allen key and or to remove slight slop in the fitting, not hold the shaft on.
It's a grade 5 fine thread bolt and self locking nut.
Everyone of those models are the same, B2781A/B and the B2782A/B.

View attachment 54420

There was never that bolt and nut #190 + 180 on my snowblower shaft to begin with! So all the torque on the shaft went through the #070 key for the last 3 1/2 winters. Time to fix that! I'll check, but just curious, what's the diameter and length of that fine thread bolt? My manual is out in the seriously frozen shed.

 

[nbryan]

Thanks everyone!

There's no sign there was ever a through bolt installed in the shaft coupling. Can't see any wear marks from a bolt, head or nut, all looks like new. Tomorrow I'll find a 1/4" x 2 1/2" bolt for it and that should solve it.

 

[North Idaho Wolfman]

Thanks everyone!

There's no sign there was ever a through bolt installed in the shaft coupling. Can't see any wear marks from a bolt, head or nut, all looks like new. Tomorrow I'll find a 1/4" x 2 1/2" bolt for it and that should solve it.

Not the first time I've heard that one.
It is quite scary and damaging when that shaft comes off at full operating RPMS.