Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Hello all. In the process of rebuilding  this blower and apart from replacing a couple of bearings, I found that the idler arm for the tractor section is really warn and causes quite a bit of arm deflection. It would probably run ok but I am concerned about premature belt failure.

In the photo below, (sorry for the bad focus) you can clearly see that there is a 1/8" grove worn in the shaft and the hole it goes into is also worn oval by at least 1/8 ". So, I'm open to repair suggestions.

I could weld up the shaft and regrind, but you need to be careful of the cotter pin hole.
I could also weld up the bracket & re-drill but it's tough to get to the back side.
I also thought about grinding off the welds on the shaft head & replacing it with another bolt of the same diameter, but I'm not sure of the clearance for a nut to hold it in on the back side of the bracket.
Then there is the deluxe fix by welding in a piece of steel tubing between the two tabs of the bracket. Then the shaft would be supported along the entire length & be much less likely to wear and the arm remain well aligned.



What say you???

Here is a pic from the parts manual to show the whole idler arm & where it goes (# 46).



 This arm controls the traction drive not the auger. In the original photo above, the frame is upside down to get a better view. The worn pivot pin is like a bolt that is inserted into a hole in the idler arm then welded in place, so it shouldn't take much to grind off the weld & replace the pin. The problem is with the holes in the bracket that it pivots in. Flanged bearings are a good idea, but I don't think the bracket is big enough to drill a hole large enough to fit in a bearing. Maybe a needle bearing, I'll do some more research tomorrow.

Thanks guys.   

Flanged bushings, like on the auger or axles, would only be 1/8" - 1/4" thicker diameter than the shaft.  Can get some type of plastic/nylon or oil impregnated bronze.

I actually thought most of those idlers had bushings already, guess yours didn't.

Unfortunately the tab in the front is only 3/4" wide and the pin is 3/8" so there is precious little room to drill oversize. All the flanged bearings I could find were 5/8 wide leaving 1/16 per side (in theory). Metal bushings would work if they were thin enough, but I think plastic would wear out too fast. I did find some steel tube, 3/8 ID with a 1/16 wall that I could also use as a bushing. I could always replace the pivot pin with a slightly smaller one to give me more room for a bearing. hopefully it wouldn't be too weak to hold up to the bending forces.

Anyways, here are some photos of the area in question. As you can see, I am stripping her down for paint. Rust looks alot worse than it is. It's only a very light surface coat because I used acid to attack the few rougher spots.

First, a wide shot of the main tractor section chassis, looking from the front towards the rear of the machine. (arrow points to the offending bracket)


Second, a closer look at the bracket, same point of view.


Third, a shot with the idler arm in position. As you can see, the pivot pin is like a bolt welded into a hole in the bracket, so it would be easy to grind off the weld and replace the pin.

Nice pics. Heres my 2 cents. From your first pics I can't tell if your pivot is threaded but in diagram #'s 49 & 50 look like its a threaded part.Also the bracket in the diagram is not in the same orientation as in yous last pics.And last what is the cotter pin hole for? Anyhow I would go about it like this.Use a steel block. After having a perfect hole machined for the shaft I would center it and weld it in between the two tabs of that bracket so that the pivot has good support.Replace the pivot with a bolt, weld the head to be flush enough for belt clearance, and have a long enough shoulder (smooth no threads)so that the threads start just inside the back side of frame where bolt comes through the other side.Have just enough thread for a washer and hefty bolt.Tighten(lock)bolt against end of thread leaving just enough movement for pivot but not enough for slop.If you can't afford the room for the nut in the back use plan 2 which is: Same steel block idea,except you will need to shorten the block between the two tabs of the bracket in such a way that you will weld the the block to the back portion of the bracket and leave enough space to use cotter pin hole. In plan 2 you can leave original pivot and rely on block for support.

Go for it and weld in the tube.

GtWtNorth,

   Impressive job on tractor base restore.  It looks great.  That’s a super model to restore.  It’s got to be one of Ariens all time classic Ariens models.  Post picture along the way and the final. 

So, I finally decided to take the plunge and drill out the hole to put in a piece of tubing. Toughest part was trying to drill the hole as true as possible to the original location. I think the outcome will be a trouble free fix.
Here is a shot of the completed repair with the tube tacked in place. The end of the tube is sunk just below the face of the bracket so it doesn't rub on the bracket arm.



I also ground off the weld on the original pin on the bracket, removed & replaced it with a high strengh bolt.



Now, you may be wondering why this part is yellow and the main body is orange? Well, I decided to go with a non stock color scheme, bright yellow for all the moving parts inside the tractor body and orange for the rest. (Kind of a safety reminder for myself) Haven't decided on what color I will use on the inside of the bucket yet, but the augers will probably be yellow (maybe black tips)
The restoration is still ongoing because we aren't getting much snow here and my trusty MTD is still serving me well.

Now that you have the tube in place. Are you going to cut the bolt longer than the previous rod and drill it for the cotter pin on the end to hold it in place?  I'm guessing there is
plenty of room for a longer rod. Yes?

Did you consider brazing the hole and then redrilling it? Or did you think that brass would be too soft for the purpose?

jrtebor - there is plenty of length for a nut on the end but I will shorten it a bit to make sure there is no interference. I'll use a nyloc nut so there will be little chance of it vibrating off.

tkrotchko - I did consider brazing & welding but I think this gives the shaft support along it's full lenght so there will be no re-occurrence of the problem and dis-alignment of the idler arm.

Cheers