Introduction: Replacing a Broken Coupling Hub
First, I'm not sure that Instructable is the perfect place for this but I thought someone might find this useful. Also, I'm a computer geek and just pretending to know something about repairing snow blowers. It is really easy any with these steps anyone can do it.
I live in Michigan and have a pretty big driveway. Rather than pay for snow removal I decided to just buy a MTD snow blower attachment for my Cub Cadet LGX 1054 riding tractor (lawn mower). I used this all last winter and it worked great.
This year I got my snow blower all setup and took it out on its first voyage of the year and quickly ran over a large stone! I heard a loud bang and then it was no longer shooting the snow out. I wasn't sure what it was at first and thought maybe the shoot was just clogged but I was not so lucky. Soon I found the rock and a broken part on the driveway. Luckily I was able to look this part up online and found a replacement on Amazon.
Enough with the story....let's get to the instructions! I will outline the steps I took to replace the broken Jaw Coupling Hub. Overall it was pretty easy and if you can take the snow blower on/off your tractor then you can definitely fix this.
Step 1: Remove the Cover
The first thing you need to do is remove the snow blower attachment and then take the drive shaft off. I will not go into removing the snow blower in these instructions but let me know if this is of interest and I may add it to another Instructable in the future.
Once the snow blower is removed from the tractor I stood this up with the auger blades facing down to the ground. I was then able to take off the cover by removing the 1/2" nut & bolt from each side. Now I could see the missing coupling that joins the drive shaft to the auger shaft and the broken plastic spider.
Step 2: Remove the Drive Shaft
Next remove the four 9/16" bolts holding in the drive shaft. I also removed the small bar which held the drive belt in place. You may not have to remove this but that made it easier to work with the belt out of the way. In my case the coupling on the drive shaft side still looked good but make sure you inspect this and replace if any doubts.
Step 3: Add the Replacement Spider and Coupling
I removed the broken plastic spider (elastomeric element) and cleaned the drive shaft. I placed the new spider on the old coupling hub. I put the new coupling on the auger drive shaft. When putting the new coupling on I had to line up the hole for the keyway pin and then tap the square pin into the hole (luckily I didn't loose this piece when the original coupling broke). After the keyway pin is secure there is a small set screw on the side of the coupling to tighten which will hold everything in place.
After this it was as simple as putting the two sides together (a little harder than it sounds). When it was together I bolted down the drive shaft and put it all back together.
When it was all fully assembled again and I attached the snow blower to the tractor again I was finally able to test this. It is working great so now I had to go finish cleaning off the driveway three days later! I have used this a few times now without any issues.
Step 4: Parts List
Before I took on this project I called the dealership and they said their service center was booked for over a week so that wasn't going to work. They did have the parts for almost $80 and service fees on top of that. I looked online and found what I needed on Amazon for a lot less. I ended up ordering two couplings and a five pack of the plastic spiders.
- Lovejoy 10690 Size L075 Standard Jaw Coupling Hub
- 0.75" Bore
- 1.75" OD
- 0.82" Length Through Bore
- Price: $5.88
- Lovejoy 10626 Size L-AL 075 Open Center Type Jaw Coupling Elastomer
- 3/4" Open Center
- 1.75" OD
- 0.44" Length
- Price: $8.61