How do you change the drive belt?

After looking under the hood at lunchbreak, it actually does look pretty straightforward.

Should I put a mark on the adjustment bolt to mark where the original position was...?

snipped-for-privacy@gmail.com wrote:

=== The article describes a serpentine belt. You should have two accessory drive belts, one for the alternator and A/C compressor and a second for the power steering. The recommended method for tensioning the larger belt is a Burroughs belt tension gauge. I found one on eBay for $50 after looking for a while. First time I checked (dealer installed belt) it was off by around thirty pounds. For the smaller power steering belt you can use the "click it" type gauge which should be available at NAPA, but IIRC, the max belt width for those is 3/4" so I didn't feel it would be as accurate for the alternator belt. That adjustment bolt arrangement for tensioning on the Gen. III Camry is the easiest method I've ever seen and if you have the Burroughs gauge you can watch the dial move as you tighten the belt so is easy to get a precise setting. I think most people just guess based on belt deflection, but that is far less accurate. Have heard excessive belt deflection can actually accelerate bearing wear, though not sure how much a factor really. I did notice at the correct setting, when you bring up the engine speed the belt does not vibrate. The Factory setting seems tight to me, but I have checked the published figure in several places - around 120 lbs. with A/C and after several years the alternator bearing is still fine, plus you probably get a bit more power if the belt isn't flopping around excessively. Of course, over tightening is not recommended. Best simply get it right. As you may know, I always use Toyota parts, including the belts. They appear to be extremely well made to my view with numerous reinforcement plies. Also, the tension changes after five minutes running, so you should re check them with the "used" belt setting in the service manual.

Thanks for the info.

Burroughs belt tension gauge, huh... sounds interesting.

I just made a mark on the metal square (which slides up and down based on the adjustment screw's position) and tightened the new belt to that same mark. No more wiggling when I run the A/C. Although, the belt wiggles slightly when the car idles... hmm...

Where did you get your Burroughs? eBay? (Harbor Freight doesn't carry one. :-)

Michael

I know new tension gauges are hard to find. It's obvious Toyota dealers don't use them. So I settled for the Krit-it II Micro-V gauge for about ~$20 from NAPA.

Specified initial tension is usually 30% above operating tension. You'll have to retension after 5 minutes of operation (I personally go

10). Old belts can stretch and new belts can have some minor variations so the "old mark" method is very accurate. You're almost guaranteed to over tension a new belt that way. Auto tensioners have been around for decades. It's a shame Toyota doesn't use the automatic tensioner on all the belts even in the post 2002 2.4L engine. Cost too much bulk I guess, so you'll have to spend to get a gauge.

A properly tensioned belt will hold most of its tension until near the end of its useful life. And properly tensioned belts in a properly aligned drive system will seem stationary while operating except the print marks on them. Over-tightening will cause the pulleys to wobble and that's not good for them and it stresses the belts.

Also, check for pulley misalignment (not operating in the same plane) as part of the belt replacement process.

rockauto.com has good prices on Gates belts, hoses, and timing components kits. But NAPA is more convenient and faster. I shop both.

In the old days, like when dinosaurs roamed the Earth, belts were tensioned using a jack screw. The jack screw (a long bolt) was turned to tighten or loosen the belt, and a lock bolt on the jack screw prevented it from loosening afterwards. Of course, the pivot bolt on the other side of the alternator had to be loosened to allow you to tension. Then both the pivot and lock bolts needed to be tightened to specified torque (such as using a $14.99 Harbor Freight torque wrench on sale). Modern designs use the Serpentine system developed by Jim Vance of the Gates Rubber Company (see below).

The basic steps are:

1. Loosen the necessary bolts and remove the old belt(s)
2. Clean the pulleys of oil, grease and dirt and allow to dry
3. Check to make sure the pulleys are in the same rotational plane without misalignment. This can be done with a simple straight edge.
4. Install the new belt(s)
5. Tension the belt(s) to specified initial tension and run the system for 5 minutes. A new belt, after running for 5 minutes, is considered "old belt" tension wise.
6. Retension the belt to specified operational tension

"A serpentine belt is a single, continuous belt used to drive multiple peripheral devices in an automotive engine, such as an alternator, power steering pump, water pump, A/C compressor, air pump, etc. The belt may also be guided by idle pulleys, and/or belt tensioners. Not all cars have an air pump; cars without an air conditioner (A/C) don't have an A/C compressor. It was invented by Jim Vance while working for the Gates Rubber Company, and first used by Ford Motor Company for the

1979 Mustang.

It is more efficient than the older multiple belt system. By using a single, wider belt instead of multiple, thinner belts..."