V8 Timing Belt - Help with Idler Replacement PLEASE!!

[MoonshineV8]

I am really hoping someone on here can come to the rescue. I am right in the middle of replacing the timing belt on my 2009 V8 and I am having issues with the replacement #1 idler pulley (it's the one on the passenger side for the tensioner held in place by the 10mm allen head bolt/sleeve. After torquing the allen bolt to 25 ft-lbs per the SM, the idler refuses to pivot around the sleeve like it should in order to properly tension the timing belt.

Before anyone asks.....YES I did make sure the thick washer was installed on the backside between the engine and the idler bracket. The old idler moved very freely and I am reusing the sleeve/bolt and washer. I have measured the thickness of the castings because it seems like just tightening down the bolt is somehow locking it in place like it is too thick or something but it is the same as the old idler. There are not any burrs or defects in the materials as far as I can tell that would keep things from rotating. I've compared bearing and casting numbers and everything is a match. The idler is part of the Aisin TKT-021 kit which includes the belt, water pump, gaskets, tensioner, and both idler pulleys.

Please reply if you have any suggestions on what might be going on. I am really hoping I don't have to go pop another $100 for another idler.

 

[rdruss]

"Sounds" like you checked everything. Can't you take that idler back and swap it for a different new one? The bearing in it may be defective, or misassembled somehow.

 

[BlackWorksInc]

I am really hoping someone on here can come to the rescue. I am right in the middle of replacing the timing belt on my 2009 V8 and I am having issues with the replacement #1 idler pulley (it's the one on the passenger side for the tensioner held in place by the 10mm allen head bolt/sleeve. After torquing the allen bolt to 25 ft-lbs per the SM, the idler refuses to pivot around the sleeve like it should in order to properly tension the timing belt.

Before anyone asks.....YES I did make sure the thick washer was installed on the backside between the engine and the idler bracket. The old idler moved very freely and I am reusing the sleeve/bolt and washer. I have measured the thickness of the castings because it seems like just tightening down the bolt is somehow locking it in place like it is too thick or something but it is the same as the old idler. There are not any burrs or defects in the materials as far as I can tell that would keep things from rotating. I've compared bearing and casting numbers and everything is a match. The idler is part of the Aisin TKT-021 kit which includes the belt, water pump, gaskets, tensioner, and both idler pulleys.

Please reply if you have any suggestions on what might be going on. I am really hoping I don't have to go pop another $100 for another idler.

Can we get a picture of what you're talking about? It sounds like probably a casting defecting. I have started getting in the habit of scrubbing those things with a soft brass brush and then a very light coat of moly or engine lube to make sure they're nice and free-spinning.

 

[MoonshineV8]

I'm 99% sure now that it is a casting/machining defect in the bracket. It looks like the bracket of the idler is a little too thick...and I'm talking maybe a few hundredths of a millimeter....so instead of the washer tightening against the allen-head screw with the bracket floating/pivoting in between, it is tightening against the idler bracket keeping it from pivoting. I have a brand-new Toyota OEM idler waiting for me at the dealer that I will be picking up this afternoon. Fingers-crossed and I will update the thread after I get the new one installed and checked.

Thanks for the responses....that's why I love this forum!

 

[MoonshineV8]

I picked up the new idler from Toyota and got it installed. Sure enough, it is working fine now and pivots around the 10mm allen bolt/cylinder exactly how it should. The OEM part number of the idler I'm talking about is 13505-0F010 (this is for a 2009 with VVT-i just in case it may be different for other years and configurations).

I had also posted this issue on a YouTube tutorial video made by Timmy the Toolman and he replied that he had heard of this exact same issue several times in the last few weeks. Apparently there are some QC issues with these idlers. His tutorial is fantastic by the way...extremely thorough and full of little things that you won't find in the service manual that make it a bit easier. Here is the link to part 1 of 2: https://www.youtube.com/watch?v=zRPhl1xcYYw

I hope this helps anyone who purchases the same Aisin TKT-021 kit (or any #1 idler assembly) and runs into the same issue. Be aware that the defective idler I received in the Aisin kit and the one I just received from my dealer are 100% identical to the naked eye (same Koyo bearing with matching numbers, same markings on the bracket casting and hardware) but one is just a hair (literally a hair) narrower allowing it to pivot properly.