Dawg’s idler pulley project

I've decided to start building one of those idler wheels for the alternator belt.  I have a belt on the car now that is much less than a year old and it's starting to squeal already.  What a pain.

So here we go.

Because I already had the bearings and steel, I decided to make a dual bearing wheel.  Should last forever that way. 






Here is the shoulder bolt I made from a larger bolt.  It's shoulder lets it act like an axle without "pinching" the bearings.





Next I need to make the bracket.  Then I will trial fit everything to determine where I want the wheel to sit and how thick the spacer will need to be to center the belt.  Ideally a simple washer will do.

Stay tuned.

gesus man is that a pulley or a flywheel LOL.   :)  Ya I'd say that will last forever, and probably keep the engine running if it dies for a second.  

I'm coming down the home stretch.  I finished the bracket this afternoon but then realized the water pump is worn out.  So installing the idler will have to wait till I get the new pump in there tomorrow.



Here's the final assembly.  Look closely and you will see that I slotted the mounting holes.  This will allow some up and down adjustment which could come in handy.  If I make more of these I'm considering slotting them even more.  We'll see.








I can't wait to see it all finished.  Anything like this that makes the car more reliable is such a feel good project.  Wasn't expensive either. 

Well, after I pay for the the new water pump and alternator I may not feel quite the same....:)

The Dawg

i have the rodney dickman one on my car ....and honestly it works great for a week ..then i have to tighten the alt agian ...starts to get a lil squeek in the rain ...very annoying..im going to look at an actual tensionor now ...one a side note that looks well built :)

You could be right Kevin.  On the day I'll have to keep an eye on the flexing for sure.  It feels pretty darn rigid however.  Like most days, I built it with what I had in the metal bin....:)

It would be easy to modify either way.

If you look at your diagram, which I used as a guide thank you, you mention drilling clearance holes for 17 and 15mm bolts.  Those would be huge bolts indeed.  I believe those bolts are 12mm actually.  (shank diameter)

I went to put the assembly on last night and I ran into a few snags.  For starters, I think I'm going to have to back pedal a bit regarding the offset.  With the water pump off, it sure looks like the bolts indeed are offset by quite a bit after all.  I measured a little over 3/8".  Originally I placed the bracket on the bolt heads and looked down to see if it was parallel to the belt.  It seemed to be.

I'm going to wait till I actually get it mounted before spewing numbers this time....:)

A couple more snags came up also.  I tried to remove the lower bolt with a large 3/8 ratchet and no way.  I was pressed for time so decided to tackle it another day.  I had already installed a new water pump and alternator and it was getting dark and spooky.

Then I noticed the bolt right below it was not tight. 




I've never been down this low on the motor.  Could my problem be that the weight of the motor is sitting on the top bolt?  I tried to tighten the bottom one but it appears to be bottoming out.

I'll have to dig a bit when the sunshine returns.

The Dawg

Yes, the bottom leg will need to be longer.

The Dawg

I'm estimating 3/8.  It really isn't that critical.

The Dawg

I had some spare cash last week so I was able to fill up my Argon tank.  This means TIG welding time!

I modified the bracket to include a 3/8" offset between the two mounting points.  It sure looks like a lot but the ruler don't lie.  Hopefully this will lend itself to perfectly even pressure across the whole belt.

Also, since I was making a fairly major modification anyway, I decided to add some rigidity as Kevin suggested.  This came in the form of two gussets.

Rather than upload the images in this message I simply updated the originals above.

If it's nice this weekend, I'm going to try and get it all installed.

The Dawg

Thanks!  I'll get it right eventually...:)

The Dawg