Defective idler arm?

[jwasbury]

As part of my rebuild, I'm replacing the old style idler arms with the updated ones. I had nasty wear on the idler pivots.

The pulley wheel is binding on the right side (P/N 930-105-510-00). It seems like the bores on either side of the arm that the pulley shaft presses into are not square to each other. The pulley wheel spins fine, then once you press the shaft home, its binding up. I need to use a plastic hammer to press in the shaft on the new idler arm, while it goes in without effort on the old arm.

Seems like a crap part to me. Anyone else seen this? I thought these new arms were supposed to be an upgrade! New left side is fine BTW.

[lindy 911]

Curious, did you also replace the shaft in the chain box? If you had big wear in the idler I would suspect the shaft to have wear as well. If you did replace it, how big of a job was it?

Lindy

[jwasbury]

Shaft was toast indeed:



I had the machine shop replace it for me.

[Henry Schmidt]

Supertec arms are not susceptible to these kind of issues.
They also react more favorably to pivot shafts with inconsistent surfaces.

[LeakProof]

Try some 400 grit crocus cloth with Marvel Mystery Oil, worked great for me. Or perhaps those shafts are to far gone.

Correct me if I'm wrong, I do not think those shafts can be replaced in the chain housing.

Henry, I need to get some of those arms I couldn't find them on your site.

What's the cost for the right and left? (if you can't answere this, I will contact you)

Mike.

[jwasbury]

Folks,

Just to clarify, the issue I was posting about is that the idler sprocket wheel is binding in the idler arm (a brand new part).

The idler pivot shaft in the chain housing pictured was indeed replaced by my machine shop with a good used piece. I purchased two newer style idler arms to replace my old style idler arms. My understanding is that the larger bearing surfaces and bushings are improvements to the design which should hopefully prevent the wear that I experienced with the old style set up.

So...again...the idler sprocket itself was binding in the NEW idler arm (right side only). I sent the part back to Pelican, and have a new one on the way.

[lindy 911]

Hope Henry is watching: I just ordered a set of Supertec arms and I assume by looking at the design that I don't need the spacer any more? My shafts don't look as chewed up as these shown but I do have some wear. I am going to polish them as mentioned above unless Henry says no.

Lindy

[Henry Schmidt]

Originally Posted by lindy 911

Hope Henry is watching: I just ordered a set of Supertec arms and I assume by looking at the design that I don't need the spacer any more? My shafts don't look as chewed up as these shown but I do have some wear. I am going to polish them as mentioned above unless Henry says no.

Lindy

Hey Lindy
Thanks for your order.
You are correct, no spacer is necessary.
Polishing the support rod to ensure a smooth contact surface to aid in freedom of motion makes sense. One benefit to the full width bushing is that it has more contact area so slightly marred support rods can still function properly.

[Speedalac 930]

I just had a new factory left side arm break off at the ear on my race 930. Not good!

[jwasbury]

Originally Posted by Speedalac 930

I just had a new factory left side arm break off at the ear on my race 930. Not good!

Great! Something new to worry about...just what we needed.

To update and close out my issue...the new right side arm arrived from our host and its perfect. This also confirms that the original brand new part was defective. Such a simple piece its hard to imagine how it could be screwed up like that.

[Walt Fricke]

You just never know. I once noticed that the left chain tensioner seemed to be more extended than usual, and that the idler arm foot it bore upon was up closer to the top of the chain housing than normal. Chain wear? I took the idler off and noticed that there was a fracture in the forging which resulted in the arm part or whatever you want to call it being at a greater angle than it should be. Luckily it hadn't broken, though. Just luck on top of bad luck or bad parts.

[LeakProof]

That's a trip.

[lindy 911]

For all of you who are interested: I just received my Supertec idler arms and they are PERFECT. I mean the sprocket shafts fit better than stock and they are a perfect fit on the chain box shaft. It took almost ten minutes to take the originals out, take them apart and reassemble the new ones with the stock shaft and sprocket, and then reinstall them into the chain box. Of course my motor is on an engine stand at the moment!

Just another excellent, excellent product from Henry Schmidt and Supertec.

Lindy

[LeakProof]

I will be purchasing those lovely arms also.
Defiantly, good piece of mind and insurance.

Mike.