Timing Belt Idler Bolt Length

[912126]

Hi,

I am replacing an idler pulley (Passenger/Right Side-Upper) that failed.

From pictures of pulleys for sale, it appears I might also need a new, shorter bolt.

The existing bolt, when screwed alone into the block, leaves 0.40 inch space; engine-to-bolt-head underside.

The old idler is 0.59 inches thick, so there is 0.19 inch of margin now.

Pictures on RockAuto and ebay seem to show pulleys thinner than 0.59 inches.

Any new pulley thinner than 0.40 inch will not be held in place with the existing bolt. I will need to tap the hole deeper (it is drilled to 1.1 inches), or buy a shorter bolt. Finding a suitable bolt could be as difficult as finding a new pulley.

I found no references when I searched the LC BBS posts, recent and archived.

Has this been an actual problem? If so, what have you done?

Any places that have dimensioned drawings of their (for sale) idlers ?


Thanks for your help.

'90 Legacy wagon 168k miles

[Legacy777]

All the timing belts are pretty much the same width. I would question whether it's the correct idler pulley. I may have an old pulley somewhere I can try and take a measurement for you.

If I don't postt back in the next day, shoot me a PM or email to remind me.

[912126]

Didn't make my self clear enough (especially the "The old idler is 0.59 inches thick," part).

All pulleys are 35 mm wide, but the bolt is recessed into pulley.

Pulley comprises: thin-wall outer cylinder, two ring bearings, and solid inner cylinder with thru hole for bolt passage. This inner cylinder is counter-bored so bolt head is recessed. Depth of counter-bore determines bolt length required. I need: [(35mm) minus (counter bore depth)] dimension from new pulley to determine if old bolt is too long.

My pulleys are original. Most "good" car owners would have faced this years ago. That is, if indeed there really was a change to face.

From the lack of response, I guess this never was a problem.

Thanks for responding,

D

[Legacy777]

Ok, I looked in the parts book and have a better idea of what's going on. Subaru changed the pulley design mid-way through the first gen Legacy. So the 92-94 legacies had a different pulley design, which I think you discovered that required a different length bolt. Anyway, the easiest solution is probably going to be to get the newer style bolt.

You can try and find it used, or If you can get me the month & year your car was built (will be on the plate in the driver's door area) I can tell you what the part # is of the newer bolt.

Alternatively, if you want you can d/l the parts book from me and look up the part #'s yourself. Take a look at the notes in the thread, it tells you how to decipher the comments in the parts book.

http://bbs.legacycentral.org/viewtopic.php?t=30531

[912126]

Thanks

I just ordered a couple idlers, so I'll wait 'til they arrive.

Too much ado over a bolt, but I thought my post might ring a bell with someone who could just say "order this one".

Thanks again,

D