when should serpentine belt, timing belt and tranmission fluid be changed?

[fido_fido]

hi,

Parents of mine is wondering of when to change the serpentine belt, timing belt and transmission oil, Currently the car (2000 Toyota Sienna) have 139,099 km on the ometer. and what about the spark plugs? i was told 160k from dealership. My parents are driving to Florida, Miami week after next week so they want to knw when is the best time to change so they don't have to change in the states.

They never did any maintanence to the car except for brakes, oil w/oil filter of course, air filter, rad coolent and rust proof. all that within 7 years of ownership. Me and my parents are not good at maintaining cars that well, so any exra tips would be great.

Thanks,
Chris

[Spud72]

The manual will have the recommended service intervals.

Go with that.

Chances are they're coming close to due on the tranny, probably past due on the belt if they are still running the factory one.

You parents can probably register on ClubToyota.ca https://clubtoyota.toyota.ca/tohp/experience/en/home/index.jsp?wosid=VEg4C1VmJwVECPXNIrUv50&woiid=23 and it should give them all their recommended service intervals plus service history.

[hytong]

http://www.toyota-onlinemm.ca/NewVersion/Cache/1/1255/EN-CA/149_2_2000_Sienna_Automatic_6-Cyl_2WD_km_136000_64.PDF
or
http://www.toyota.ca/cgi-bin/WebObjects/WWW.woa/9/wo/Home.Owners.MaintenanceMenu-wKSUdfAHbtK9xZsrr2pWSw/36.13?o110000e%2ehtml

[ES_Revenge]

Serpentine belt, whenever it's worn IMO. This belt is readily/easily inspectable visually so it's easy to tell when it should be replaced. Replacing it earlier than necessary is not a big deal here either as the belt is usually relatively inexpensive so it's one of those "cheap insurance" things you could say.

Timing belt and trans fluid, I would follow the manufacturer specified intervals as mentioned already. Timing belt is pretty crucial in this area particularly on interference engines where you'll really be kicking yourself if the belt breaks because you didn't change it on time!

[Pete_Coach]

A serpentine belt is readily/easily "visually" inspected alright but it is far from easy to tell if it is worn. There are many types, from grooved to ridged to v groove but unlike in the old days, just looking for cracks in the belt webbing or surface is not enough. The belts are made from many different materials and layers and the tensioners put strain on both sides of the belts nowadays so, the OEM recommendations are ever more important to follow. Sometimes you may hace to remove them to get a good look at them.
Same goes with the timing belts. Each OEM often has their own material specs and the OEM recommendations are items which should be followed. Having said that, the OEM understands us and is fully aware that we do not always do as they require and have a relatively large safety margin incorporated into their recomendations so a few thousand kilometers over will not be critical.
Fluids, well, they generally work to worst case scenario. You should stick as closely as you can to the suggested fluid replacement intervals.