colinnwn Posted February 15, 2015 Share Posted February 15, 2015 I was getting belt squeal starting up in the morning that would go away within about 15 seconds. I hadn't changed the belts in over 6 years so I figured it was time. I put in new Nissan belts (in addition to an electric radiator fan conversion that I'll do a separate writeup on). Man if you don't have the fan in the way, belt changes on these engines are stupid easy. I don't have a measuring tool to figure out the correct tension. I've read on here it should be pretty tight, but I also didn't want to ruin any of my accessory bearings. I believe the FSM says the A/C belt should flex no more than 9 mm with 22lbs of pressure between pulleys, and the main belt 5 mm. I tried to gauge this by finger and sight. I thought I had the belts overly tight and it turns out I had at least the main belt way loose. For the A/C belt which I haven't been able to test yet, I just used a socket wrench extension and turned the adjusting bolt as much as I could by hand with only the extension. For the main belt I did the same, and then I put the wrench on the extension and gave the adjusting bolt one additional full turn. The first day I had no squeal, the 2nd I had a chirp, the 3rd it was a couple seconds long. I tried putting a few drops of dish soap on the belt on the inside and out. The 4th day it squealed a few seconds longer. So I gave the adjusting bolt a half turn more. For the next 2 days I had very small chirps. I just gave it another half turn, for a total of 2 turns past hand tight, and it looks like that's going to be the perfect tension. Just thought this might help someone 2 Link to comment Share on other sites More sharing options...
anyexcuse Posted February 17, 2015 Share Posted February 17, 2015 Yes it may! Mine has a squeal for a few seconds after starting it and I need to look into it. Thanks for the info! 1 Link to comment Share on other sites More sharing options...
CDN_S4 Posted February 17, 2015 Share Posted February 17, 2015 Thanks for this, I have the start up squeal too, 2-3 seconds. Sprayed it with belt lubricant but didn't really make a difference. So you're saying tighter made it better...interesting. I was thinking mine were too tight maybe. I'll check back after I tinker around with this a bit. Link to comment Share on other sites More sharing options...
kdj Posted February 18, 2015 Share Posted February 18, 2015 (edited) I'd say it's NOT your belts slipping but your idler pulley squeeling. I thought I had a loose belt till I checked out the idler. When I took the pulley off it would barely turn by hand it was so gummed up. WD40 and compressed air...put it back together and I had no squeel. The belt wasn't the problem. Edited February 18, 2015 by kdj 1 Link to comment Share on other sites More sharing options...
CDN_S4 Posted February 18, 2015 Share Posted February 18, 2015 ^^ good to know!! Did you take it off for that? Or just removed the belt? Link to comment Share on other sites More sharing options...
colinnwn Posted February 18, 2015 Author Share Posted February 18, 2015 When I had my belt off I could spin the idler pulley easily. I would expect the squealing to last longer or not stop if the idler was gummed up. Is that not the case? Link to comment Share on other sites More sharing options...
Kingman Posted February 18, 2015 Share Posted February 18, 2015 Could try taking some fine grit sandpaper to the inside of the pulleys to knock the glaze off. Grippy grippy is no squeaky squeaky. 1 Link to comment Share on other sites More sharing options...
kdj Posted February 18, 2015 Share Posted February 18, 2015 With mine I thought it was a belt but the adjuster bolt was siezed so that's why I had it all apart, which was a great time to remove all the AC stuff. Who needs AC in Canada? Cleaned up the idler and injected bearing grease into it. Quieter now than before it started squeeeling. 2 Link to comment Share on other sites More sharing options...
colinnwn Posted July 9, 2017 Author Share Posted July 9, 2017 I just finished replacing my alternator, and used the same belt from this thread. For the last couple months before the alternator had gone out, I had been getting the occasional startup belt chirp. I had been planning to tighten it up another half turn. But after the alternator replacement, starting from a removed, old but good condition belt - I again hand tightened the tensioner with just the extension, and did one full turn with a wrench. That seemed too loose by pressing on the belt, but I actually didn't try starting it up. I did another half turn, for a total of 1.5 turns, and then the belt felt appropriately tight. There was no chirping on startup. Link to comment Share on other sites More sharing options...
colinnwn Posted February 1, 2019 Author Share Posted February 1, 2019 I had to replace my alternator again, and when I did I noticed that the idler pulley turned freely, but it made a light clicking noise. So I replaced it. The engine idles much smoother and quieter. now I couldn't separately detect it from the rest of the engine noise, but the old idler must have been clacking around. It was a Dayton part from Advance Auto Parts. At first I was flustered because the dust cap wouldn't fit on it. But then I read the box closer, and it said the new one had a sealed bearing and discard any old dust cap. I didn't bother removing the AC belt and checking that idler pulley. I guess sometime I will. Link to comment Share on other sites More sharing options...
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