TunedRX300

Many RX300 and ES300 owners have the squeaking noise from AC/alternator belt. Even though my mechanic changed a new AC/alternator belt for the RX last year, belt tension decreased over time. I decided to get rid of of the noise during cold startups by tightening the belt a little. Here are DIY instructions and pictures I took along the way. Please feel free to post correction if you find an error.

Step 1: Lay out tools
Required: 12mm six point socket, wrachet (1/2" drive in picture), 12mm open end wrench (one in RX's tool bag)
Optional: Autozone Serpentine Belt Loaner Tool



Step 2: Check Current Belt Tension
pop the hood, locate the alternator the belt we adjust connect three pulleys: AC, Alternator and crank.



I don't have a belt tensioner measurement tool, so I twist the belt and found I can turn more than 90 degrees, obviously that needs to be tightened.

TunedRX300

Step 3: Loosen Adjusting Lock Bolt

The adjusting lock bolt is right under the adjusting bolt. It is tougher to reach and I found it is easier to mount the 12mm socket to the shorter rod w/ 1/2" drive in Autozone's loaner tool.



If the locking bolt is too tight, you can get additional leverage by connecting the longer handle with the shorter rod



Once loosened, I used wrachet to turn and kept the wrachet on the bolt until I am done adjusting.

TunedRX300

Step 4: Adjusting Belt Tension
The adjusting bolt is just above the locking bolt. Use the 12mm open wrench to turn the adjusting bolt clockwise to tighten. Check the belt by twisting belt, I stopped when I could no longer twist it past 90 degree. I did not loosen the pivot bolt since I am not going to replace the belt.



Important: There is not a lot of space between the alternator and AC condenser fan. I got around by using my left hand to help to wedge the wrench onto the bolt, using my right hand to turn at the same time. It requires a lot patience and wrench flipping to not to strip the bolt, perhaps a 12mm wrench with build-in wrachet can save some agony.

Step 5: Tighten the Adjusting Locking Bolt

After belt tension is adjusted to your desired level, just tighten the adjusting lock bolt. I first used the short rod + 12mm socket to tighten until I get enough space, then use wrachet to finish it off.

Last step is put tools away and turn on the car and check for noise. I had couple of cold starts and squeak is go e

FYI, if one wants to replace AC/Alt belt, here is a good link:
http://autorepair.about.com/library/faqs/bl794h.htm

thomas1

Nice tuturol thank you

salimshah

Nice!

90degree twist is nice to know. I am still looking for a cheap tool to measure tension. In past I have overtensioned the belt and runined a bushing of an old waterpump. Fortunately the SC and RX have serpentine blets with tensioner pully.

Salim

[7]

LiqrSicc

Exactly what I needed. Thanks TunedRX

ppcpilot

Do you just need to loosen the locking bolt, or take it all the way out?

TunedRX300

Just loosen the locking bolt, I don't think you can take it out

dhg2496

Have you had any other problems with your AC or Alternator? I was thinking of trying a new belt or tightening the existing belt to see if that fixed mine.

Thanks for posting this information, it's great to have this info!

TunedRX300

If your mechanic determines AC compressor is bad, you can get a Denso one at www.rockauto.com, get further discount by Google the 5% discount code.

Belt is cheap, I would replace it since there is no additional labor charge. I used Gates belts for both my Acura and Lexus, same quality as OEM, just slightly cheaper from Rockauto and saved me trips to dealers.

99jewel

Ditto on the kudos to TunedRX. Finally a clear & concise description with pictures. Thanks!!!!!!!

Ribuchen

wow i just joined the forum and found what i was looking for thanks

Pogophil

Perfect! This was what I needed today. Mission accomplished.

TunedRX300

Thanks for the feedback. Couple days ago a radio auto show explained why belts squeaks at cold, it is because rubber contracts when the temperature is hotter, so the belt wraps around the pulley tighter than when it is cold.

edbro

I'd of thought just the opposite. Don't things expand in heat and contract in cold?