Coupler on MTD snowblower busted....

[Castleford]

I run an MTD snowblower attachment on my lawn tractor and about 2 years ago 1/2 of the Lovejoy coupling snapped so I replaced it along with the plastic insert/spider. The model number is 190-032.
This coupling connects the output shaft of the right angle drive to the input shaft of the impeller.

Today the entire coupling shat the bed,all 3 jaws on one side gone, the jaws on the other half has badly damaged jaws but the spider is more or less intact, surprisingly.
I figure those couplings should last longer than 2 years so I've done something wrong during my last repair.
The only adjustment i could see was sliding the individual components back & forth on their respective shafts so I gave them about 1/4" clearance between them.
Has anybody had any experience with these couplers,secrets to installing them properly?
Thanks...

 

[StarTech]

The Lovejoy assembly when all components are new will properly space itself individual components as there are spacer tabs on the rubber coupler insert. But sounds like you have either something moving around miss aligning the coupler or have maybe an U-joint or auger gearbox problem from wear.

Due costs of the Lovejoy from MTD you might consider checking out Grainger under "jaw coupling hub and spider" components. This allows to mix and match the jaws mounting hole for different shaft sizes. They they also another type Lovejoy system.

 

[Castleford]

I think it's possible that I had set the 2 metal segments too far apart, I'll pay closer attention to the clearance when I reassemble the new joint, make it 'snug'.

Yah, the $119 CAD (+ tax & shipping) price for a new Lovejoy assembly sure is eyewatering, I did in fact order the new parts from Grainger for $52....(Tax & shipping incl)
Thanks!

 

[Castleford]

I found this on You Tube.

 

[Castleford]

Well, this is as snug as I can make it....used a few trashed screwdrivers as pry bars to ensure the 2 jaws are as close as possible to each other...website sez 'picture is too large', film at 11....here's the pic...sorry for the quality, Windows has taken charge.

 

[Castleford]

And the above repair lasted a couple of hours,just long enough to dig out from a major snowstorm.
The coupling was noisy with vibration, so the spider was the first to go, 3 of the 6 arms detached.
Back into my shop, it was obvious that the alignment was poor.
Luckily I had a spare urethane spider so here it is shown prior to adjustment.
The problem was the rightangle transmission was sitting low at the back and a lot of force was needed to bring that up,and forward.
After a few attempts I hit upon using a couple of pry bars with 2 clamp set 'backwards'....here is one set up before setting the 2nd one.A lot of force not apparent here....

The alignment is drastically improved, and I ran it for an hour doing cleanup, no noise or excessive vibration. The spider is intact....time for a happy dance!

 

[disallow]

Just had the same experience withthe same unit. Been using it for most of last year and this year. Last year was nuts. Not sure if anything else has been damaged on the Auger Shaft side of things or in the worm gearbox. But noticed the alignment sucked when I initially put it together. Also, the allen bolts came loose when I fired it up. Am thinking of putting some never-come-off juice onto these to prevent them from backing off. Supposed to snow this week, so we shall see!

Grainger took over 3 weeks to get me my parts. Not happy but now I finally have them and installed.

 

[Castleford]

Just had the same experience withthe same unit. Been using it for most of last year and this year. Last year was nuts. Not sure if anything else has been damaged on the Auger Shaft side of things or in the worm gearbox. But noticed the alignment sucked when I initially put it together. Also, the allen bolts came loose when I fired it up. Am thinking of putting some never-come-off juice onto these to prevent them from backing off. Supposed to snow this week, so we shall see!

Grainger took over 3 weeks to get me my parts. Not happy but now I finally have them and installed.

I would definitely use thread locking compound, alignment is critical for a happy joint but there's not a lot of room for a straight edge/small machinist square to ensure this, as recommended by the mfgr's documentation so I just used the method as described. Low noise & vibration is my goal.I know what you mean about Grainger, but I guess we're stuck with them until McMaster Carr starts selling to non commercial entities outside the US....