I've replaced the drive belts on my Corolla. I went with Bando EPDM, except for the conventional (nonribbed, noncogged) A/C belt, for which there is no correct aftermarket part. So, that one got Toyota OEM made by Mitsuboshi, luckily very cheap. Bando is also an OEM for Toyota. All belts seem to be of high quality.
The hardest part of the job was putting the wrench on some of the bolts where there is little space from the wall. I needed some extension on the wrench as well. Sockets wouldn't go in there.
I used the following exact formula for the belt tension, assuming my right index finger applies 10 lb of perpendicular pressure:
(Deflection of belt) = (0.25)*(span length of belt between the two pulleys where the force is applied)*(perpendicular force applied on belt midway between the two pulleys)/(belt tension)
I've also replaced the A/C idler pulley with a Dayco one. The Dayco has a made-in-Taiwan standard tightly sealed NTN bearing. The Toyota OEM 88440-12160-83 has a Nippondenso custom bearing. OEM is a heavier pulley, of same or very similar geometry, with a loosely sealed bearing. To my dismay, it was unavailable in USA at the time I needed it. The Dayco pulley seemed to fit well but it has more seal friction because it's the tight-seal type. I'm not sure if the OEM pulley had gone bad but I was occasionally hearing some pulley noise coming from somewhere. The coating on the OEM pulley was also gone.
Toyota/Nippondenso OEM 88440-12160-83 A/C idler pulley. Note that one of the edges is thinner than the other -- same with Dayco. The Nippondenso (ND) date code on the pulley bearing dust cover is May (E = 5) 1983.
Dayco 89039 pulley:
The hardest part of the job was putting the wrench on some of the bolts where there is little space from the wall. I needed some extension on the wrench as well. Sockets wouldn't go in there.
I used the following exact formula for the belt tension, assuming my right index finger applies 10 lb of perpendicular pressure:
(Deflection of belt) = (0.25)*(span length of belt between the two pulleys where the force is applied)*(perpendicular force applied on belt midway between the two pulleys)/(belt tension)
I've also replaced the A/C idler pulley with a Dayco one. The Dayco has a made-in-Taiwan standard tightly sealed NTN bearing. The Toyota OEM 88440-12160-83 has a Nippondenso custom bearing. OEM is a heavier pulley, of same or very similar geometry, with a loosely sealed bearing. To my dismay, it was unavailable in USA at the time I needed it. The Dayco pulley seemed to fit well but it has more seal friction because it's the tight-seal type. I'm not sure if the OEM pulley had gone bad but I was occasionally hearing some pulley noise coming from somewhere. The coating on the OEM pulley was also gone.
Toyota/Nippondenso OEM 88440-12160-83 A/C idler pulley. Note that one of the edges is thinner than the other -- same with Dayco. The Nippondenso (ND) date code on the pulley bearing dust cover is May (E = 5) 1983.
Dayco 89039 pulley:
