Drive belt engine

**dr. d** · October 29th, 2019 11:38 AM

i would replace my belt, when it shows minute cracks on the ridged inner surface. kuripot ako.
others would replace theirs, after every xxxx km, regardless of belt condition. pms to the fullest definition! heh heh.

**bokswager** · October 29th, 2019 12:25 PM

Thank you guys for the inputs. Papasadahan ko nalang for the next PMS if due for replacement na talaga. More power tsikot!!

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**H1Tman** · September 18th, 2024 02:35 PM

Napansin ko yung drive belt Altis ko parang may tahi sa outer part. Tapos ngaun parang lumalalim na yung tahi. is that a sign to replace?

**Dr.Kamiya** · September 18th, 2024 11:09 PM

Originally Posted by H1Tman

Napansin ko yung drive belt Altis ko parang may tahi sa outer part. Tapos ngaun parang lumalalim na yung tahi. is that a sign to replace?

From the 4runner forums: Replacement OEM Serpentine Belt fraying?! | Toyota 4Runner Forum

I contacted Bando for a definitive answer. They’re the ones producing these made in the USA OEM belts for Toyota.

Here’s the engineer’s response:

“That fraying will eventually wear off. The fabric is only stitched to hold it in place during the building of the belt. The rubber impregnated fabric is cured to the backing of the belt so the stitching isn’t relevant to the functioning of the belt during use.

Most auto manufacturer’s have transitioned to a rubber backed belt without any fabric backing. As I mentioned on the phone, our aftermarket belts do not have the fabric backing.”

I bought a second belt from Toyota and it’s obvious the same stitching will have similar results. Glad there’s nothing to worry about.

Hopefully this might help someone else.

So seeing the stitching apparently means your belt is still fresh since it hasn't been thrown off yet.

**dr. d** · September 19th, 2024 12:14 AM

i pay attention to the cracks that might appear on the inside, perpendicular to the long axis.

the other week, i had the altis belt replaced.
it didn't have many cracks, but it had been making squeaking noise when started from cold in the morning.
i googled and saw the squirt-water test.
ok na si new belt. tahimik na ulit.

**jick.cejoco** · September 23rd, 2024 06:40 AM

One of the indicators of a premature worn serpentine belt is the sign of the pulley groove crest that is polished and the groove valley of the belt being in contact with the pulley crest. The belt was designed to have contact with the inclined surfaces of the belt and the pulley. Also check for debris stuck in the pulley grooves.